SUUUPER frustrating Code 14(Ignition Signal) OBD1 issue.
SUUUPER frustrating Code 14(Ignition Signal) OBD1 issue.
I have a 1995 sc300 stock 2jzge. OBD1 obviously. I have gotten codes 14, 42, and 47. (After I picked it up from the shop it's only throwing code 14 now)
I have left my car at the shop for almost the WHOLE summer. Trying to get this issue fixed. He attached a lab scope to the car, and tested spark, distributor, ignition/igniter, alternator, a/c voltage, timing, crank and cam shaft signals. Even attached a fuel pressure gauge to the car and it stayed in the 58-60 range while the car did the "hickup". After three weeks of consecutive testing, the shop decided to let the car go because they hit a dead end. So I'm still here with a messed up car. When they gave the car back to me, they said that it was an injector pulse issue as far as they can tell.
Here's the issue.
I have an inconsistent breakup/stutter on the car. It will not happen at all times during driving the car, only seems to happen when I accelerate/decelerate instead of keeping a steady speed. Now, here's the symptoms:
While on the gas, and accelerating, the car will out of nowhere lose gas/bog down, like if I took my foot straight off the pedal extremely fast. Now mind you, my foot is still on the gas pedal and the car will act like it's idling(Mind you I'm also 5-speed so it will start to decelerate because I'm still in gear). I have to re-apply the gas in order to get it going again.
And the car will seem to stutter randomly. Like what I just described above, but it seems like it's just happening faster and fixing itself, it will re-apply the gas/acceleration and will jerk the whole car.
What I've tried to replace myself to fix this:
I have replaced the TPS, Igniter(twice), Ignition coil, cleaned out my whole throttle body and replaced the air filter.
Could the issue be ECU or MAF related?
I have left my car at the shop for almost the WHOLE summer. Trying to get this issue fixed. He attached a lab scope to the car, and tested spark, distributor, ignition/igniter, alternator, a/c voltage, timing, crank and cam shaft signals. Even attached a fuel pressure gauge to the car and it stayed in the 58-60 range while the car did the "hickup". After three weeks of consecutive testing, the shop decided to let the car go because they hit a dead end. So I'm still here with a messed up car. When they gave the car back to me, they said that it was an injector pulse issue as far as they can tell.
Here's the issue.
I have an inconsistent breakup/stutter on the car. It will not happen at all times during driving the car, only seems to happen when I accelerate/decelerate instead of keeping a steady speed. Now, here's the symptoms:
While on the gas, and accelerating, the car will out of nowhere lose gas/bog down, like if I took my foot straight off the pedal extremely fast. Now mind you, my foot is still on the gas pedal and the car will act like it's idling(Mind you I'm also 5-speed so it will start to decelerate because I'm still in gear). I have to re-apply the gas in order to get it going again.
And the car will seem to stutter randomly. Like what I just described above, but it seems like it's just happening faster and fixing itself, it will re-apply the gas/acceleration and will jerk the whole car.
What I've tried to replace myself to fix this:
I have replaced the TPS, Igniter(twice), Ignition coil, cleaned out my whole throttle body and replaced the air filter.
Could the issue be ECU or MAF related?
Yes, unplug the KMV and see how it runs without it. If it runs good then it's most likely the KMV sensor, however even with it unplugged it could also be ECU still.
Most of the time when an ECU fails the car smokes white, especially when cold.
Most of the time when an ECU fails the car smokes white, especially when cold.
fuel pump ecu bypass?
I'm not sure about 95's but in the diagnostic box in the engine bay (small black box says either diag or diagnostic on the cover) jump the pins that say FP and B+ with a paper clip and see what it does.
I'm not sure about 95's but in the diagnostic box in the engine bay (small black box says either diag or diagnostic on the cover) jump the pins that say FP and B+ with a paper clip and see what it does.
It's alot of info i posted on those codes, i'll teach you how to use the tools on this board once you learn that you will love it!
The search botton on top of your post , it's between New posts botton and the quicklinks botton in blue, hit the drop down botton and then select adcanced search.
So on the top left ("search by keywords") type code 14 and you will get all these answers below.
https://www.clublexus.com/forums/sea...earchid=158749
Gl
The search botton on top of your post , it's between New posts botton and the quicklinks botton in blue, hit the drop down botton and then select adcanced search.
So on the top left ("search by keywords") type code 14 and you will get all these answers below.
https://www.clublexus.com/forums/sea...earchid=158749
Gl
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It's alot of info i posted on those codes, i'll teach you how to use the tools on this board once you learn that you will love it!
The search botton on top of your post , it's between New posts botton and the quicklinks botton in blue, hit the drop down botton and then select adcanced search.
So on the top left ("search by keywords") type code 14 and you will get all these answers below.
https://www.clublexus.com/forums/sea...earchid=158749
Gl
The search botton on top of your post , it's between New posts botton and the quicklinks botton in blue, hit the drop down botton and then select adcanced search.
So on the top left ("search by keywords") type code 14 and you will get all these answers below.
https://www.clublexus.com/forums/sea...earchid=158749
Gl
linky no worky.
you really don't want to drive your car with a code 14. It is not very good to do that the ecu goes into a failsafe where it is more or less in open loop just to keep things running (barely in most cases).
thats is why when you hold it steady it seem smooth, but as soon as you accelerate it will hesitate, this is a symptom of your code 14. this is not actually the problem itself.
there aren't many things it can be with a code 14. The shop should have found it honestly.
They didn't really need to do half the things they did. fuel is not related to code 14, when the ecu misses the IGF signal it sets code 14 and cuts off fuel from the cylinders who didn't report back an IGF.
you either have a bad ignitor (usually unlikely), you have a bad ignition lead from the distributor to the coils (also unlikely), you have a bad contact in the cap or the rotor is worn in the distributor which causes a cylinder or 2 to randmily misfire (very likely and it will happen to every sc300 sooner or later if you don't replace these parts at the proper intervals), you have a short in your IGF wire (fair chance), or the pin is a little loose at the ecu or ignitor (also believe it or not happens quite often). your ground at the intake manifold has been left unconnected (would probably cause more problems than just code 14 but ill throw it out there).
what does your rotor and cap look like, that would have been the first thing I would check, and you don't need a scope, its a visual check.
if you haven't changed them out yet you may want to start there. If you have a spark jumping around in there sooner or later you will be buying a whole new distributor because it will fry one of the 3 very important sensors sitting right under the rotor.
thats is why when you hold it steady it seem smooth, but as soon as you accelerate it will hesitate, this is a symptom of your code 14. this is not actually the problem itself.
there aren't many things it can be with a code 14. The shop should have found it honestly.
They didn't really need to do half the things they did. fuel is not related to code 14, when the ecu misses the IGF signal it sets code 14 and cuts off fuel from the cylinders who didn't report back an IGF.
you either have a bad ignitor (usually unlikely), you have a bad ignition lead from the distributor to the coils (also unlikely), you have a bad contact in the cap or the rotor is worn in the distributor which causes a cylinder or 2 to randmily misfire (very likely and it will happen to every sc300 sooner or later if you don't replace these parts at the proper intervals), you have a short in your IGF wire (fair chance), or the pin is a little loose at the ecu or ignitor (also believe it or not happens quite often). your ground at the intake manifold has been left unconnected (would probably cause more problems than just code 14 but ill throw it out there).
what does your rotor and cap look like, that would have been the first thing I would check, and you don't need a scope, its a visual check.
if you haven't changed them out yet you may want to start there. If you have a spark jumping around in there sooner or later you will be buying a whole new distributor because it will fry one of the 3 very important sensors sitting right under the rotor.
Last edited by Ali SC3; Aug 30, 2012 at 01:08 PM.
I found it HILARIOUS that I found a thread that has exact symptoms that I'm having with my car.(Except its a 1jz)
https://www.clublexus.com/forums/per...ideas-pls.html
Unforunately the OP never said if he resolved the issue or not.. So we're still clueless.
I can't thank you guys enough for putting some input in on this, I'll keep you updated on the status of the car!
https://www.clublexus.com/forums/per...ideas-pls.html
what makes this so annoying is that its so random...I started her up and drove around for an hour or so with no problems. I checked continuity from the IGF wire next to the coil down to the ecu, no problem. I took a look at all the coils and wires, they are all good since i replaced all the pigtails when i did the swap over a year ago.
I ended up taking out the ecu, opening it up and looked for some leaking caps. It looked pretty cherry inside but i sent it out to driftmotion to replace the caps for me. Hopefully that will be my issue...
I ended up taking out the ecu, opening it up and looked for some leaking caps. It looked pretty cherry inside but i sent it out to driftmotion to replace the caps for me. Hopefully that will be my issue...
I can't thank you guys enough for putting some input in on this, I'll keep you updated on the status of the car!
Hey I have a few updates. So idk if I mentioned this, but my car has also been having battery drain issues that we haven't been able to figure out at all. So today after I decided to open my trunk after turning off my car/locking it with the alarm I noticed my fuel pump was still on. There was humming from inside the tank and it was still vibrating/working while the car was off and completely locked. Even with all the doors shut and the trunk shut, you could still hear the fuel pump while putting your ear to the trunk/rear windshield.
I unplugged the the fuel pump directly from the harness plug ontop of the pump. Could this be a step in the right direction for my stutter issue as well? At this point should I check and fix the fuel pump relay system on the car if damaged and keep the same fuel pump? Or get a new fuel pump all together/bypass it? Give me some ideas guys!
I unplugged the the fuel pump directly from the harness plug ontop of the pump. Could this be a step in the right direction for my stutter issue as well? At this point should I check and fix the fuel pump relay system on the car if damaged and keep the same fuel pump? Or get a new fuel pump all together/bypass it? Give me some ideas guys!
I found out that my Main EFI Relay is going bad. It heats up really hot, and causes my fuel pump to stay on after I turn off the car. What could cause a EFI relay to die out? I even replaced the current relay with the Defrost relay(same one) and it burned through that one too after a day's worth of driving.
