2jznosht

That was actually similar to my problem...my pile was hard to start, but eventually would fire up and run until I put it in gear, then it would die. New fuel pump and it ran like a dream

slappy96

I would say there is only a 1% chance its your fuel filter and a 10 % chance it's your fuel pump.

If you pull the fuel line off at the intake or loosen a banjo on the fuel rail and get any kind of pressure...I think your issue is electrical/ground ***injectors not getting electricity to work***.

The starter fluid thing is normal for 5-20 seconds or so then die.

You have verified spark + air and fuel is all that is remaining. I just don't think it pump/filter.

IS_Sunny

iTrader: (1)

Sure sure... good reply. Thanks

I agree in the sense that it would seem odd to me for it to be the fuel pump or filter, since the car was running 100% fine until it sat for 3-4 weeks.
As in... what would make the fuel pump randomly die, or the fuel filter get clogged when the car was never started, run or used whatsoever.

Now the car DID work right after I changed the alternator and battery, for about 2 days before I never tried it again (for a month)... so I still think it would be a bit odd that it's a ground or electrical. If that was the case then I'd expect the car to have never worked once after the alternator / battery replacement.

100% spark, timing and air are working. The car gets full battery power when the key is turned.

So I assume I should recheck and make sure, SURE that the alternator connections / ground and the battery ground is good...? Anything else, electrical, that I should check in terms of the injectors not getting power?

Would that be a dead ECU (or ECM) / "computer" maybe?


I'm serious about buying you a pizza... lol.
For real though!

_

GS4_Fiend

iTrader: (22)

Definitely check fuel pressure and fuel volume under load before jumping to conclusion. Also check power and grounds on the fuel pump circuit.

slappy96

I've been reading and re-reading trying to think this through...

Back to the beginning--what led you to the conclusion that the alternator was bad?

You didn't have a reverse polarity episode with the new/old battery did you? (Highly doubt or you would have mentioned--but I have to ask)

What's leading me down the electrical ground route (specifically the 2 grounds on the lower intake runner) is that with fuel filter issues I think it would have run poorly or poorly under load first. Note poorly...not run at all.

You have verified spark. Not necessarily good spark or spark at the right time--but spark. Was the distributor or associated wires/ignitor disturbed/moved at all when you replaced the alternator.

"Usually", the 'sat a while and now it won't run' episodes provide enough opportunity to finally corrode ground connections that have been teetering on the brink for a while. (This is all assuming that there are none simply loose or disconnected)

In for more.

IS_Sunny

iTrader: (1)

Alright... time for a bizarre, yet Fortunate update

My last post in this thread has the latest updates. On Saturday I verified spark and got the car to start for about 5 seconds with some starter fluid. It wouldn't start again after that (w/o starter spray).

Being that I was discouraged and it was 90 degrees outside everyday, I didn't do a thing else to the car.
Today I thought... Man, I really need to go out there and at least put the car in neutral and roll it back a bit to avoid getting flat spots on the tires. When I get in, I thought... what the hell, I'll give it a try.

The freaking car fired right up and ran like a dream.
I let it run for a few and tried it again. Once more, perfect start. No hesitation, no rough idles... as if there was never a problem.
I started it 5 times in total and drove it for 5 miles in my neighborhood. All is well.

What in the heck could have happened?
My only though is that there was a clog somewhere in the fuel filter or line that we cleared when it started (with started fluid) and floored the throttle. The reason it did not start again when I tried after that was because we maybe flooded it with gas from pulling back on the throttle cable?

I honestly couldn't tell you what the deal was. This car LITERALLY did not start for a month. Now it's perfect??!?!

This old SC just won't die (*knocks on wood)

IS_Sunny

iTrader: (1)

TLDR:

My car (94 SC300 w/ 225k miles) would not start once for a full month. It turned over but wouldn't crank.

• I replaced the battery
• Cleaned the battery connections and ground
• Removed 1 spark plug and verified a spark
• Checked all fuses (all were good)
• Checked oil and fuel levels (both good)
• Started it two times for 5-10 each time with starter fluid (wouldn't start again).
• I didn't actually "fix" anything. I basically just checked stuff...

4 Days later I try to start the car and it fires right up. It's ran and stated all day without any problem whatsoever.

but

A BIG THANKS to all the posters in this thread who took the time and care to read and try to help me out with suggestions.
This is what CL is all about. You guys ROCK!!!!

slappy96

Still running without issue?

klobb92

I now have a similar problem! And i really need some input. 1995 sc300. car miss fires. But runs smooth when actually running. if you press the gas too hard it will like choke. sometimes it stops doing it. havent pinpointed how exactly. There is a loud rumbling from the gas tank that you can hear inside the car im not sure if thats normal or not. And serious pressure build up in gas tank when you pull off cap. Was told possibly spark plugs, MAF, Fuel filter or Fule pump. But drove to my sisters house and her driveway is sloped, with the nose of the car up. 20 min later i try to leave and the car wont start. tried pushing to level ground still nothing, And i dnt hear the rumbling anymore from the gas tank , but i do hear two clicks from the back driver side of the engine. Can anyone give me some insight or advice. *PS Cant go to a machanic because when they see a young person with this car they try to cahrge me alot. Thanks!

jschru

iTrader: (1)

Bumping this thread up. I'm having a similar problem. Was working on my car earlier trying to diagnose a missfire/bog under hard acceleration on my na-t running a jdm aristo ecu. Figured I have a bad ground on my coil packs so I was checking the wiring with a multimeter. Out of nowhere the engine shut off and now it won't start at all. I have no power at the fuel pump, even with the 12v mod, tried jumping fp, and b+ pins on the diag port and still nothing. Car turns over but won't start, efi relay seems fine I swapped with the def. relay and still nothing. I pulled a plug and it was bone dry so it's not flooded. I'm stuck. Any help or advice is appreciated.

klobb92

Try jump starting it from another car. i had the same prob too.

MrGetRT

My car started then abruptly sputtered out. Does anyone know where i can find information on checking the fuel pump relay, and or fuel pump. the engine wants to turn over it just seems to lacking gas.

pyr8

Any resolution for anyone? Having the same issue on a 94 LS400.

tzxlyd

I just stumbled on this post. I am having the same issue that I am reading from this thread. My car will not start and I thought it was the alternator. The symptoms are similar to those here. The problem began over a month ago, I would start car and it would appear to misfire while idling very rough. I could take off and there was hesitation with backfires for about a quarter mile but after that car would run fine. There were problems when stopped at red lights/stop signs with the idle dropping very low as if the car wanted to die. I sometimes had to step on the gas pedal for fear of the engine stopping. I suspected spark plugs wearing or 1 or 2 dead. I intended aving them replaced. I thought that was hard to believe since I had all plugs replaced about 50K miles ago, along with coil pack, cap/rotors, serpentine belt, etc. granted this was 3 1/2 years ago but I generally do not average any more than about 10K miles a year driving. However, I was doing a great deal of chauffeuring of dad to medical appointments for a couple of years since having them replaced so I thought it was possible. 3 weeks ago I was the victim of a hit and run so the car has been sitting up in the garage since 2/26/15 with front bumper and right fender damage that rubs when turning. Car has not moved much -- it was starting but running very rough requiring the gas pedal almost floored to keep it running. The battery was draining about 12V -- I thought because it was just sitting without being charged from driving. I took off the negative terminal while it was sitting. What made me suspect bad alternator was lots of corrosion on the battery so I thought it was starving for power and pulling on the battery. To test my theory I started car and while running I took the negative terminal off the battery -- the car would die. I thought that combined with the rough idling, corrosion on battery and engine dying when negative terminal removed meant alternator not working. Well, I charged the battery while the car was just sitting there and the claims adjuster came to inspect the car on 3/4/15. I reconnected the battery terminals to pull the car out the garage but the car would not start -- it cranked fine -- just would not start. You could clearly hear the engine trying to turn over so it was not a starter problem and I had checked the battery after charging it with 13.3 V so it was not the battery. I just assumed it was the alternator so I ordered a rebuilt alternator and replaced it on 3/12/15. I charged the battery again overnight with a trickle charge back to 13.3 V and waited until yesterday to fire it up expecting it to crank right up -- unfortunately it would not start. I tried to jump it with another vehicle but it still would not start so I went and bought some starter fluid thinking it must be a fuel issue -- still it would not start. I have a new tune-up kit that includes cap/rotor, plugs, belt, etc. -- I ordered the complete kit because I was going to have it done later this year or early next. I saw a pretty good price on the complete kit for $200 with free shipping so I thought with the idling problems I would need to replace everything soon anyway. However, before I replace anything else I need to isolate this problem and this thread seems to be in line with my issue -- 1) car was running until it sat for a while, 2) cranks fine but will not start -- 3) additional threads had rough idling plus 4) back fire, etc. So I am hoping someone out there has identified the issue before I apply this shotgun approach to the problem that will not be very helpful in understanding what is the real problem with the car not starting.

grumpi300

iTrader: (1)

seems like everybody is forgetting/doesnt the fact that sc300's have a fuel pump ecu which is prone to go bad. easiest way to tell is to jump the connectors on the diagnostic port under the engine bay.
https://www.clublexus.com/forums/per...tures-faq.html
somewhere in this forum it tells you how to jump the pins and which pins to use.