No Spark or Fuel, what else am I missing?
08-05-16, 07:01 PM
#1
Rookie
Thread Starter
No Spark or Fuel, what else am I missing?
Bought this car a few weeks ago. 92 SC300 M/T, 250k on Chassis, Unknown miles on replaced 2jzge. That same week I replaced Thermostat, Radiator to cure a higher than normal temperature.
For the most part, the Car has been running fine. I have been driving it with no issues, but did notice it consumed fuel more than usual, but nothing out of the ordinary like smoke or anything like that. I noticed one day, however, when cold, the car had good noticeable amount of power, but warmed up I could tell it lacked power when accelerating. I showed a video of the car idling and AliSC3 could tell it was misfiring. With all of this, I figure it was only a matter of time before the ECU was going to give out. When I opened the ECU area I noticed the Car has had ECU replaced with a Junkyard 95 M/T Ecu (Not Rebuild) by previous owner.
I drove it last week on a hot day for a few miles, came home and the next day it would crank but NOT start. Nothing out of the ordinary, no warning, no hesitation, nothing. Was supposed to take it in to put a Catalytic Converter on that next morning and it just cranked and cranked.
What I noticed:
- No fuel pump noise
- No spark upon crank at plug wires and coil wire going into Cap.
- Heater fuse blown (No coin in cig lighter); replaced.
- No CEL
Troubleshooted:
-New plugs, wires,cap, rotor.
-New starter.
-New Battery.
-Tried a different Fuel Pump ECU.
- Relays: Main Ignition and EFI : Good.
-Timing belt: good
-Head Gasket: no slushy oil.
I decided to send the ECU to Tanin last week and literally just got it today. Plugged it in with excitement, turned the key and same deal, no dice.
- Noticed Heater fuse blown again; replaced.
- Replaced Ignition Coil.
What else am I missing guys? I've read a few posts but the ones that were related to what I was experiencing did not report back results. I'm reluctant to replace the igniter unless someone can suggest that it could be it, but know that AliSC3 always mentions that igniters do not commonly fail.
These old bones are tired of troubleshooting. The hot weather does not help.
Thank you for any suggestions.
For the most part, the Car has been running fine. I have been driving it with no issues, but did notice it consumed fuel more than usual, but nothing out of the ordinary like smoke or anything like that. I noticed one day, however, when cold, the car had good noticeable amount of power, but warmed up I could tell it lacked power when accelerating. I showed a video of the car idling and AliSC3 could tell it was misfiring. With all of this, I figure it was only a matter of time before the ECU was going to give out. When I opened the ECU area I noticed the Car has had ECU replaced with a Junkyard 95 M/T Ecu (Not Rebuild) by previous owner.
I drove it last week on a hot day for a few miles, came home and the next day it would crank but NOT start. Nothing out of the ordinary, no warning, no hesitation, nothing. Was supposed to take it in to put a Catalytic Converter on that next morning and it just cranked and cranked.
What I noticed:
- No fuel pump noise
- No spark upon crank at plug wires and coil wire going into Cap.
- Heater fuse blown (No coin in cig lighter); replaced.
- No CEL
Troubleshooted:
-New plugs, wires,cap, rotor.
-New starter.
-New Battery.
-Tried a different Fuel Pump ECU.
- Relays: Main Ignition and EFI : Good.
-Timing belt: good
-Head Gasket: no slushy oil.
I decided to send the ECU to Tanin last week and literally just got it today. Plugged it in with excitement, turned the key and same deal, no dice.
- Noticed Heater fuse blown again; replaced.
- Replaced Ignition Coil.
What else am I missing guys? I've read a few posts but the ones that were related to what I was experiencing did not report back results. I'm reluctant to replace the igniter unless someone can suggest that it could be it, but know that AliSC3 always mentions that igniters do not commonly fail.
These old bones are tired of troubleshooting. The hot weather does not help.
Thank you for any suggestions.
Last edited by nsjuice; 08-05-16 at 07:18 PM.
08-05-16, 08:47 PM
#2
Rookie
Thread Starter
After starting this post I went back and cranked the car. This is the first time it actually sounded like it wanted to start and I could smell fuel in the air from the exhaust? Still no sound from Fuel Pump however.. not sure if there's supposed to be but I do remember hearing it once, as I thought to myself, "What's the sound? Oh, fuel pump." Not sure of the difference but I don't hear it or notice fuel pump noise in my 97 SC400, or maybe because i'm not hunting for it.
Anyway, here is a video of the SC3 cranking:
Anyway, here is a video of the SC3 cranking:
08-07-16, 04:55 PM
#3
Well Ill just say things I can tell from the video that might be helpful.
first few times you crank it nothing is really happening. my guess is something electrical or the timing or the fuel is off enough for it to not want to turn over.
around the 40 sec mark you can hear it turn over once, and then on later attempts the same thing it fires off for a second but its not enough to start.
I would say this likely rules out no spark and no fuel cause that noise is telling me you got a small combustion there.
still to test the fuel pump and bypass the fuel ecu, you can jump FP and B+ in the diagnostic port and that will turn on the fuel pump.
you will hear the fuel pump and the fuel running through the rail even with the motor off. still a worthy test to do is why I mention give it a try but I don't think that is the issue.
Generally a cold start will be harder than a warm start, you need extra start fuel and you need the right timing, either one out and you will have issues.
since you repaired the ecu, lets assume for now its ok and the fuel should be on point ecu wise cause unless you had several injectors fail, the car would still start as long as most are working. normally a bad ecu causes overfueling but again usually starts. you could have a faulty fuel rpessure regulator but most of the time they work for the life of the car.
Where I think your issue might be is timing. if possible get a timing light and try and get a read on the timing while cranking the motor.
If you put the car in diagnostic mode you should be seeing 10 +/- degrees on the crank while cranking. if the timing is off a tooth then that will be a significant amount.
you have no idea how many people think its fine to juts line up the notches on the distributor and install it, and they don't check it. you can be quite far off if you don't check it.
Since you said a replaced motor and someone was likely having issues with it, its the first thing I would personally verify cause its the only mechanically set thing on the engine.
Now what I also think it could equally be from your description of before it stopped working when you noticed power loss when it warmed up, is your coolant temp sensor.
These don't always throw codes, but the car wont know the right temp and hen the cold start fuel mixture is off, or the hot running mixture is off. this doen't exactly explain why you aren't able to start it cold, but it sort of fits some of the symptoms you mentioned. these do tend to go bad every couple 100k, so its not a bad idea to test or replace it.
If I think of anything else I'll let you know. sounds like you are getting a spark initially then the ecu stops like its not getting IGF which is he ignition confirmation signal, so the second it misfires it cuts off the ignition as a safety feature, so you need to fix whatever is causing the missing but it could be lots of things. this also explains why you aren't seeing spark cause after the first misfire the ecu is likely shutting it off.
first few times you crank it nothing is really happening. my guess is something electrical or the timing or the fuel is off enough for it to not want to turn over.
around the 40 sec mark you can hear it turn over once, and then on later attempts the same thing it fires off for a second but its not enough to start.
I would say this likely rules out no spark and no fuel cause that noise is telling me you got a small combustion there.
still to test the fuel pump and bypass the fuel ecu, you can jump FP and B+ in the diagnostic port and that will turn on the fuel pump.
you will hear the fuel pump and the fuel running through the rail even with the motor off. still a worthy test to do is why I mention give it a try but I don't think that is the issue.
Generally a cold start will be harder than a warm start, you need extra start fuel and you need the right timing, either one out and you will have issues.
since you repaired the ecu, lets assume for now its ok and the fuel should be on point ecu wise cause unless you had several injectors fail, the car would still start as long as most are working. normally a bad ecu causes overfueling but again usually starts. you could have a faulty fuel rpessure regulator but most of the time they work for the life of the car.
Where I think your issue might be is timing. if possible get a timing light and try and get a read on the timing while cranking the motor.
If you put the car in diagnostic mode you should be seeing 10 +/- degrees on the crank while cranking. if the timing is off a tooth then that will be a significant amount.
you have no idea how many people think its fine to juts line up the notches on the distributor and install it, and they don't check it. you can be quite far off if you don't check it.
Since you said a replaced motor and someone was likely having issues with it, its the first thing I would personally verify cause its the only mechanically set thing on the engine.
Now what I also think it could equally be from your description of before it stopped working when you noticed power loss when it warmed up, is your coolant temp sensor.
These don't always throw codes, but the car wont know the right temp and hen the cold start fuel mixture is off, or the hot running mixture is off. this doen't exactly explain why you aren't able to start it cold, but it sort of fits some of the symptoms you mentioned. these do tend to go bad every couple 100k, so its not a bad idea to test or replace it.
If I think of anything else I'll let you know. sounds like you are getting a spark initially then the ecu stops like its not getting IGF which is he ignition confirmation signal, so the second it misfires it cuts off the ignition as a safety feature, so you need to fix whatever is causing the missing but it could be lots of things. this also explains why you aren't seeing spark cause after the first misfire the ecu is likely shutting it off.
08-07-16, 05:54 PM
#5
Rookie
Thread Starter
Tried again to no avail. Jumper works; clip is hot to the touch. No pump/fuel sounds however.
Is there a protocol to reconnecting the car ecu? After I got it back from tanin I just plugged the harnesses and bolted it back into the floorboard. Just wondering.
Is there a protocol to reconnecting the car ecu? After I got it back from tanin I just plugged the harnesses and bolted it back into the floorboard. Just wondering.
Last edited by nsjuice; 08-07-16 at 07:55 PM.
08-07-16, 09:54 PM
#6
Ness,
First off, since you're in California do you have a Cali Emissions or Federal Emissions 1992 SC300 M/T model? You said that the previous owner had replaced the original 1992 ECU with a 1995 ECU.
That may be significant. Possibly not but I want to investigate this just a bit before writing it off.
I can tell you that with my 1993 SC300 M/T with CA Emissions when I ran a 1995 SC300 M/T CA Emissions ECU it did a couple of abnormal things:
1) Since 1995 CA SC300's (and possibly 1995 Federal SC300's?) use heated O2 sensors their ECU's will be looking for those. No 1992-1994 SC300 regardless of having CA or Federal Emissions runs heated O2 sensors from the factory. When I plugged in the 1995 SC300 CA ECU I had a permanent CEL.
2) Since the 1995 SC300 CA ECU's (M/T or A/T) see heated O2 sensor wires missing they will overwork the #1 and #2 O2 sensors and dump in more fuel to compensate. The 1995 CA ECU (and possibly 1995 Federal) does this because it thinks doing so will either accelerate heating those sensors up or it just does so as compensation for more complex O2 sensor inputs it isn't getting. The result is more unburned fuel. That unburned fuel also happens to get dumped directly against your first catalytic convertor and over time it can ruin the convertor's effectiveness due to fouling.
3) I can't confirm even though I went through this same scenario but I am pretty sure using the 1995 CA ECU in a 1992-1994 SC with the ECU forcing a rich fuel condition also probably wears the spark plugs prematurely.
This is my guess: since you have the incorrect ECU in your car (even though 1995 is still considered OBD1) you had a permanent CEL light when the car was still drivable and would start. You also detect a rich fuel smell from the exhaust. You also probably have burned out #1 and #2 O2 sensors on the exhaust manifold which need to be replaced.
Now before you do all of that you really need to put a correct version ECU back into your car.
From here: https://www.clublexus.com/forums/per...s-by-year.html
If you have a 1992 SC300 M/T California model you can use any of these ECU part numbers:
#89661-24320 — 1992 SC300 M/T California
#89661-24321 — 1993-1994 SC300 M/T California
#89661-24322(84) — 1992-1994 SC300 M/T California (Toyota Reman of 89661-24320 & 89661-24321)
If you have a 1992 SC300 M/T Federal model you can use any of these ECU part numbers:
#89661-24300 — 92-93 SC300 M/T Federal
#89661-24301 — 1/92 through 8/93 Lexus SC300 2JZ-GE M/T Federal (Toyota Reman of 89661-24300?)
#89661-24302 — 1994 SC300 M/T Federal
These are not easy to find. My best luck has been by scouring ebay. When you do find one I also recommend sending that directly into Tanin for service once you have it.
It sucks that you just had them work on the wrong ECU for your car. I am sure that is in fine shape now but unfortunately it probably isn't helping your 1992 vehicle.
If you can, please tell us what the Toyota part number of your Tanin repaired 1995 ECU is?
If it's a 1995 SC300 M/T CA Emission ECU it will be 89661-24380. If it's the 1995 SC300 M/T Federal ECU it is another part number we don't yet have verified in our records here on CL.
I would check or replace your O2 sensors or wait on that until you can get a correct ECU into your SC (since the 1995 ECU will likely foul up whatever new O2 sensors you install within 1-3 months. And your #1 catalytic convertor if it hasn't done so already).
....
^^ I strongly agree that you should check this as Ali SC3 points out. Has the ECU coolant temp sensor ever been replaced? It is very possible that it has gone bad given the age since it also contributes to engine startup and maintaining idle. It is located in a hard to reach but not too hard to reach location underneath the intake manifold on the front of the engine. It also has a separate factory metal gasket that gets replaced when you install a new Toyota sensor. Member TheMole did an excellent writeup on how to do this yourself (with the engine cold of course which will not be a problem for you).
https://www.clublexus.com/forums/per...-i6-sc300.html
First off, since you're in California do you have a Cali Emissions or Federal Emissions 1992 SC300 M/T model? You said that the previous owner had replaced the original 1992 ECU with a 1995 ECU.
That may be significant. Possibly not but I want to investigate this just a bit before writing it off.
I can tell you that with my 1993 SC300 M/T with CA Emissions when I ran a 1995 SC300 M/T CA Emissions ECU it did a couple of abnormal things:
1) Since 1995 CA SC300's (and possibly 1995 Federal SC300's?) use heated O2 sensors their ECU's will be looking for those. No 1992-1994 SC300 regardless of having CA or Federal Emissions runs heated O2 sensors from the factory. When I plugged in the 1995 SC300 CA ECU I had a permanent CEL.
2) Since the 1995 SC300 CA ECU's (M/T or A/T) see heated O2 sensor wires missing they will overwork the #1 and #2 O2 sensors and dump in more fuel to compensate. The 1995 CA ECU (and possibly 1995 Federal) does this because it thinks doing so will either accelerate heating those sensors up or it just does so as compensation for more complex O2 sensor inputs it isn't getting. The result is more unburned fuel. That unburned fuel also happens to get dumped directly against your first catalytic convertor and over time it can ruin the convertor's effectiveness due to fouling.
3) I can't confirm even though I went through this same scenario but I am pretty sure using the 1995 CA ECU in a 1992-1994 SC with the ECU forcing a rich fuel condition also probably wears the spark plugs prematurely.
This is my guess: since you have the incorrect ECU in your car (even though 1995 is still considered OBD1) you had a permanent CEL light when the car was still drivable and would start. You also detect a rich fuel smell from the exhaust. You also probably have burned out #1 and #2 O2 sensors on the exhaust manifold which need to be replaced.
Now before you do all of that you really need to put a correct version ECU back into your car.
From here: https://www.clublexus.com/forums/per...s-by-year.html
If you have a 1992 SC300 M/T California model you can use any of these ECU part numbers:
#89661-24320 — 1992 SC300 M/T California
#89661-24321 — 1993-1994 SC300 M/T California
#89661-24322(84) — 1992-1994 SC300 M/T California (Toyota Reman of 89661-24320 & 89661-24321)
If you have a 1992 SC300 M/T Federal model you can use any of these ECU part numbers:
#89661-24300 — 92-93 SC300 M/T Federal
#89661-24301 — 1/92 through 8/93 Lexus SC300 2JZ-GE M/T Federal (Toyota Reman of 89661-24300?)
#89661-24302 — 1994 SC300 M/T Federal
These are not easy to find. My best luck has been by scouring ebay. When you do find one I also recommend sending that directly into Tanin for service once you have it.
It sucks that you just had them work on the wrong ECU for your car. I am sure that is in fine shape now but unfortunately it probably isn't helping your 1992 vehicle.
If you can, please tell us what the Toyota part number of your Tanin repaired 1995 ECU is?
If it's a 1995 SC300 M/T CA Emission ECU it will be 89661-24380. If it's the 1995 SC300 M/T Federal ECU it is another part number we don't yet have verified in our records here on CL.
I would check or replace your O2 sensors or wait on that until you can get a correct ECU into your SC (since the 1995 ECU will likely foul up whatever new O2 sensors you install within 1-3 months. And your #1 catalytic convertor if it hasn't done so already).
....
Now what I also think it could equally be from your description of before it stopped working when you noticed power loss when it warmed up, is your coolant temp sensor.
These don't always throw codes, but the car wont know the right temp and hen the cold start fuel mixture is off, or the hot running mixture is off. this doen't exactly explain why you aren't able to start it cold, but it sort of fits some of the symptoms you mentioned. these do tend to go bad every couple 100k, so its not a bad idea to test or replace it.
If I think of anything else I'll let you know. sounds like you are getting a spark initially then the ecu stops like its not getting IGF which is he ignition confirmation signal, so the second it misfires it cuts off the ignition as a safety feature, so you need to fix whatever is causing the missing but it could be lots of things. this also explains why you aren't seeing spark cause after the first misfire the ecu is likely shutting it off.
These don't always throw codes, but the car wont know the right temp and hen the cold start fuel mixture is off, or the hot running mixture is off. this doen't exactly explain why you aren't able to start it cold, but it sort of fits some of the symptoms you mentioned. these do tend to go bad every couple 100k, so its not a bad idea to test or replace it.
If I think of anything else I'll let you know. sounds like you are getting a spark initially then the ecu stops like its not getting IGF which is he ignition confirmation signal, so the second it misfires it cuts off the ignition as a safety feature, so you need to fix whatever is causing the missing but it could be lots of things. this also explains why you aren't seeing spark cause after the first misfire the ecu is likely shutting it off.
https://www.clublexus.com/forums/per...-i6-sc300.html
Last edited by KahnBB6; 08-07-16 at 10:02 PM.
08-07-16, 11:23 PM
#7
Rookie
Thread Starter
I guess this will force me to do the NAT sooner than expected. I had hoped to enjoy the car and slowly get parts for NAT. At the rate things are going with failing smog (needs new cat, high HC), incorrect ECU, heated o2 sensors, I might as well go for it instead of dropping extra money to get it to run stock form??? !#%@
I am not sure which model vehicle i have, how do i check? Vin#? The 95 ecu number is 89661-24360. I am only assuming it is a 1995 ecu due to the fact that it is written in yellow marker similar to those used at wrecking yards to show it is from their lot in case the buyer wanted to return it.
Im not too keen on what you mean by permanent CEL, but there were no CEL before the car died. Just to throw it out there, the First two O2 sensors have been replaced by previous owner not long ago..but if what you stated is true, they probably died out from the 95 ecu dumping fuel. However, i did mention to Ali that idle RPM is slightly higher compared to other cars. Not by much, but enough to notice, especially when ac is turned on.
I will look into temp sensor as I was going to do so to eliminate it from checklist.
What about the fuel pump not firing up after jumping it?
I am not sure which model vehicle i have, how do i check? Vin#? The 95 ecu number is 89661-24360. I am only assuming it is a 1995 ecu due to the fact that it is written in yellow marker similar to those used at wrecking yards to show it is from their lot in case the buyer wanted to return it.
Im not too keen on what you mean by permanent CEL, but there were no CEL before the car died. Just to throw it out there, the First two O2 sensors have been replaced by previous owner not long ago..but if what you stated is true, they probably died out from the 95 ecu dumping fuel. However, i did mention to Ali that idle RPM is slightly higher compared to other cars. Not by much, but enough to notice, especially when ac is turned on.
I will look into temp sensor as I was going to do so to eliminate it from checklist.
What about the fuel pump not firing up after jumping it?
Last edited by nsjuice; 08-08-16 at 12:16 AM.
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08-08-16, 01:11 AM
#8
nsjuice, don't jump to the extreme just yet. Let's take it one step at a time.
First of all I didn't say your car needs heated O2 sensors, just that this is what a 1995 SC300 CA Emission ECU expects to see.
Second, I ran the 89661-24360 part number through Carson Toyota's system and it came up as a 1995 SC300 M/T *Federal* ECU (note, since it's been verified in a Toyota parts database I have updated the ECU list thread linked above). Now all I need to verify is if 1995 Federal SC300's got heated four wire O2 sensors like the 1995 CA Emission SC300's. Something I have not been able to confirm yet... unless anyone else can help answer that.
Third, just open your hood and look at the underside labels showing the accessory belt routing, TDC specs and emission system vacuum hose and EGR routing. It should state if the car is Federal or California emissions type. Alternatively you can just take the car's VIN number and call up any Lexus dealer (or a Toyota dealer like Carson that is Lexus friendly) and simply ask them to verify if your car is Federal or Cali emissions.
I sympathize with the pickle you are in with having failed emissions. I was in this situation myself very recently and I chose to repair until I just made the testing and DMV deadline. The rub in my mind is that if you get all the NA-T hardware together instead you will still have to pass emissions somehow in stock form.
First things first, find out what emissions type your car is. Very easy to do. That way we can figure out how to address the ECU if at all.
Second I would check into the ECU coolant temp sensor. You can do this replacement yourself-- not very hard to do the easy way if you don't mind spilling a bit of coolant and refilling the radiator a bit afterward. Or you can drain the car's coolant first if you want to avoid any spillage. It is a very quick process to swap the old sensor with new. I believe there is a quick test that can be done to determine if it is bad or not.
Regarding cats, it's most probable that your #1 cat is the one at fault if you have very high HC's. Thankfully this is the cheaper factory cat to buy. And there is a direct fit Catco #1 cat you can get also if needed (but OEM is actually a just a tiny bit cheaper if available).
What I meant by "permanent CEL" was that when you put a 1995 CA Emission ECU in a 1992-1994 SC (no matter if it's a Federal or Cali emission chassis) the Check Engine Light will stay permanently lit. In your case I do not think the 1995 Federal ECU throws a CEL light, however as of my typing these very words into my reply I have just come back from doing some research and it does look like all 1995 models got four-wire O2 sensors. So I cannot yet rule it out that the O2 sensors aren't being affected at all by the 1995 ECU in your 1992 SC.
Identify your car's emissions type first and check into your ECU coolant temp sensor. Then let's go with more investigating and deduction from there.
^^ Just check into these things for the moment. Don't jump to spend money right away. Always investigate first.
On the fuel pump question I am going to defer to Ali SC3 but my guess is that if you jumped the Fuel ECU and you still don't get fuel pressure there very well be a problem with your pump @ 250k miles. The good news is that IF your fuel pump has gone bad.... IF it has... then you can get a factory replacement direct from Denso's website much cheaper than you would from Toyota or Lexus. Same exact part and original supplier.
But I have to defer to Ali SC3 on diagnosing whether or not your fuel pump has gone bad.
There is also checking the fuel pressure regulator which may have also been bad but I am not sure how to diagnose those. I believe when they go bad they are supposed to leak fuel from the diaphragm into the little vacuum hose coming from the FPR. Not sure though. Good to check and rule it out too. Always good to replace them eventually because they can affect a certain aspect of emissions if very near worn out but if it's working right now I would leave it alone until there is a reason to replace it.
First of all I didn't say your car needs heated O2 sensors, just that this is what a 1995 SC300 CA Emission ECU expects to see.
Second, I ran the 89661-24360 part number through Carson Toyota's system and it came up as a 1995 SC300 M/T *Federal* ECU (note, since it's been verified in a Toyota parts database I have updated the ECU list thread linked above). Now all I need to verify is if 1995 Federal SC300's got heated four wire O2 sensors like the 1995 CA Emission SC300's. Something I have not been able to confirm yet... unless anyone else can help answer that.
Third, just open your hood and look at the underside labels showing the accessory belt routing, TDC specs and emission system vacuum hose and EGR routing. It should state if the car is Federal or California emissions type. Alternatively you can just take the car's VIN number and call up any Lexus dealer (or a Toyota dealer like Carson that is Lexus friendly) and simply ask them to verify if your car is Federal or Cali emissions.
I sympathize with the pickle you are in with having failed emissions. I was in this situation myself very recently and I chose to repair until I just made the testing and DMV deadline. The rub in my mind is that if you get all the NA-T hardware together instead you will still have to pass emissions somehow in stock form.
First things first, find out what emissions type your car is. Very easy to do. That way we can figure out how to address the ECU if at all.
Second I would check into the ECU coolant temp sensor. You can do this replacement yourself-- not very hard to do the easy way if you don't mind spilling a bit of coolant and refilling the radiator a bit afterward. Or you can drain the car's coolant first if you want to avoid any spillage. It is a very quick process to swap the old sensor with new. I believe there is a quick test that can be done to determine if it is bad or not.
Regarding cats, it's most probable that your #1 cat is the one at fault if you have very high HC's. Thankfully this is the cheaper factory cat to buy. And there is a direct fit Catco #1 cat you can get also if needed (but OEM is actually a just a tiny bit cheaper if available).
What I meant by "permanent CEL" was that when you put a 1995 CA Emission ECU in a 1992-1994 SC (no matter if it's a Federal or Cali emission chassis) the Check Engine Light will stay permanently lit. In your case I do not think the 1995 Federal ECU throws a CEL light, however as of my typing these very words into my reply I have just come back from doing some research and it does look like all 1995 models got four-wire O2 sensors. So I cannot yet rule it out that the O2 sensors aren't being affected at all by the 1995 ECU in your 1992 SC.
Identify your car's emissions type first and check into your ECU coolant temp sensor. Then let's go with more investigating and deduction from there.
^^ Just check into these things for the moment. Don't jump to spend money right away. Always investigate first.
On the fuel pump question I am going to defer to Ali SC3 but my guess is that if you jumped the Fuel ECU and you still don't get fuel pressure there very well be a problem with your pump @ 250k miles. The good news is that IF your fuel pump has gone bad.... IF it has... then you can get a factory replacement direct from Denso's website much cheaper than you would from Toyota or Lexus. Same exact part and original supplier.
But I have to defer to Ali SC3 on diagnosing whether or not your fuel pump has gone bad.
There is also checking the fuel pressure regulator which may have also been bad but I am not sure how to diagnose those. I believe when they go bad they are supposed to leak fuel from the diaphragm into the little vacuum hose coming from the FPR. Not sure though. Good to check and rule it out too. Always good to replace them eventually because they can affect a certain aspect of emissions if very near worn out but if it's working right now I would leave it alone until there is a reason to replace it.
Last edited by KahnBB6; 08-08-16 at 01:16 AM.
08-08-16, 09:49 AM
#9
Yeah i wouldn't worry about the o2 sensor stuff or ecu difference just yet, but that may be important for actually passing emissions.
lets get the engine running first. couple of things.
bad efi relay or fuse (I cant remember which this toyota has) can mean the b+ wont have 12v in the connector. if you have a volt meter test and make sure b+ is getting 12v.
you said it was getting hot so that makes me thing that it does have 12v and the pump is toast and acting like a resistor essentially (if it failed open it would not heat up the paper clip).
one way to sort of test whether you have an electrical issue like a bad EFI relay or fuse is to run 12v directly from battery to the fp+ pin. if it turns on you know that something is preventing that B+ from getting power. again its more likely you have a pump that was on its last leg, usually starts with intermittent problems then lets go.
maybe each of those start attempts it barely works and eventually you get enough pressure to get a slight tun over and then nada, it fits the symptoms for sure.
IF you are going na-t later, just install a walboro or denso now. if you do the denso then do the 12v fuel mod with relay, or else you will burn out the stock fuel ecu.
walboro is usually fine to run off stock fuel ecu (mine has been running for a long time like that now).
I wouldn't go na-t without figuring it out. if its something hard to figure out itll just get more complicated.
lets get the engine running first. couple of things.
bad efi relay or fuse (I cant remember which this toyota has) can mean the b+ wont have 12v in the connector. if you have a volt meter test and make sure b+ is getting 12v.
you said it was getting hot so that makes me thing that it does have 12v and the pump is toast and acting like a resistor essentially (if it failed open it would not heat up the paper clip).
one way to sort of test whether you have an electrical issue like a bad EFI relay or fuse is to run 12v directly from battery to the fp+ pin. if it turns on you know that something is preventing that B+ from getting power. again its more likely you have a pump that was on its last leg, usually starts with intermittent problems then lets go.
maybe each of those start attempts it barely works and eventually you get enough pressure to get a slight tun over and then nada, it fits the symptoms for sure.
IF you are going na-t later, just install a walboro or denso now. if you do the denso then do the 12v fuel mod with relay, or else you will burn out the stock fuel ecu.
walboro is usually fine to run off stock fuel ecu (mine has been running for a long time like that now).
I wouldn't go na-t without figuring it out. if its something hard to figure out itll just get more complicated.
08-08-16, 10:51 AM
#10
Rookie
Thread Starter
Thanks, fellas, Noted. Will test fuel pump/relay/Diag. Which other Fuse is there for EFI? I swapped out the Cylindrical relay fuse in engine bay with my SC4 and it is fine. Fuse in kick panel?
I just got off the phone with Carson and it is NOT a Cali car.
I just got off the phone with Carson and it is NOT a Cali car.
08-08-16, 01:01 PM
#12
IF you are going na-t later, just install a walboro or denso now. if you do the denso then do the 12v fuel mod with relay, or else you will burn out the stock fuel ecu.
walboro is usually fine to run off stock fuel ecu (mine has been running for a long time like that now).
I wouldn't go na-t without figuring it out. if its something hard to figure out itll just get more complicated.
walboro is usually fine to run off stock fuel ecu (mine has been running for a long time like that now).
I wouldn't go na-t without figuring it out. if its something hard to figure out itll just get more complicated.
Great! Your car only needs to be emission tested for the specification it was originally manufactured with-- even in CA.
So the correct ECU part numbers for your car are:
#89661-24300 — 92-93 SC300 M/T Federal
#89661-24301 — 1/92 through 8/93 Lexus SC300 2JZ-GE M/T Federal
#89661-24302 — 1994 SC300 M/T Federal
Last edited by KahnBB6; 08-08-16 at 04:02 PM. Reason: Grammatical correction
08-08-16, 01:39 PM
#13
Rookie
Thread Starter
The ECU coolant temp sensor would be closer to the possible culprit but I am also interested what is going on with your fuel pump and fuel pressure at this moment.
08-08-16, 04:13 PM
#14
Nice work on the part numbers Kahn.
A bad coolant sensor could make it alot harder to start, but I would think it would start still after enough cranking, and work the throttle pedal while cranking can help.
generally the coolant temp sensor fits more with any misfiring when warm though.
Sounds like you have a bad pump but its hard to say definitively.. you could get to the tank and put 12v to the pump directly but I think that is what jumping fp and b+ does. since you know the fuel pump isn't coming on that is where I would start first then see how it acts cause if you did have a bad fuel pump maybe that was the source of all the issues by itself.
A bad coolant sensor could make it alot harder to start, but I would think it would start still after enough cranking, and work the throttle pedal while cranking can help.
generally the coolant temp sensor fits more with any misfiring when warm though.
Sounds like you have a bad pump but its hard to say definitively.. you could get to the tank and put 12v to the pump directly but I think that is what jumping fp and b+ does. since you know the fuel pump isn't coming on that is where I would start first then see how it acts cause if you did have a bad fuel pump maybe that was the source of all the issues by itself.
08-08-16, 04:18 PM
#15
Not exactly. Technically it should not stop the car from starting if it is defective. It would just have very hard starting from full cold or even after the car cools down slightly after running at full temperature.
Example case of a bad coolant temp sensor on a 2JZ-GE:
http://www.supraforums.com/forum/sho...nsor-Defective
I wanted to mention it to you to keep it in mind because it can affect starting but no, it shouldn't outright stop starting if it's bad.
I am very much in agreement with Ali that in order to best solve the starting issue right now you should focus on your fuel pump and the access port connections to the Fuel Pump ECU.
And since we've identified the ECU in your car right now I can tell you that isn't the cause of the car not starting. I am still fairly certain that even that '95 Federal ECU still expects four wire O2 sensors and that it may have been contributing to a rich fuel condition but that only affects the engine's optimum running, fuel economy, the health of the spark plugs, O2 sensors and #1 catalytic convertor-- not starting itself. On top of that you had Tanin repair it so there will be no internal failure with that ECU such that starting would be compromised. You should still replace it in order to pass emissions but that will be a secondary project to solve after getting your fuel system sorted out. Although as I mentioned to you over PM, grab one when you see it even if you deal with it later.
Example case of a bad coolant temp sensor on a 2JZ-GE:
http://www.supraforums.com/forum/sho...nsor-Defective
I wanted to mention it to you to keep it in mind because it can affect starting but no, it shouldn't outright stop starting if it's bad.
I am very much in agreement with Ali that in order to best solve the starting issue right now you should focus on your fuel pump and the access port connections to the Fuel Pump ECU.
And since we've identified the ECU in your car right now I can tell you that isn't the cause of the car not starting. I am still fairly certain that even that '95 Federal ECU still expects four wire O2 sensors and that it may have been contributing to a rich fuel condition but that only affects the engine's optimum running, fuel economy, the health of the spark plugs, O2 sensors and #1 catalytic convertor-- not starting itself. On top of that you had Tanin repair it so there will be no internal failure with that ECU such that starting would be compromised. You should still replace it in order to pass emissions but that will be a secondary project to solve after getting your fuel system sorted out. Although as I mentioned to you over PM, grab one when you see it even if you deal with it later.
Last edited by KahnBB6; 08-08-16 at 04:25 PM.
