starts and then stalls, when going runs perfect

[michael]

I am having some trouble it's got to be a simple fix. I have a 92 sc 400 and when I start it, the car starts and then within seconds drops below idle running rough and dies completely?? The odd thing is that when I get the car to start I have to start it and before idle can drop I have to imediately give it gas reaching approximately 3000 rpm for a few seconds then the engine idle will stay at 1000 rpm and car will run fine, perfect. No check engine light. Anybody got any ideas of what this might be, a friend of mine suggested over the phone that it could be "idle motor" he wasn't to confident, please help, thanks.

 

[Zuffen]

I would suspect the fuel pump ECU isn't working properly.

If you can borrow another to substitute for yours it's a cheap way to check.

 

[michael]

where is the fuel pump ECU located?

 

[Zuffen]

The Fuel pump ECU is located behind the rear 1/4 trim behind your (US) driver seat.

To get at it you need to remove the rear seat and the 1/4 panel trim and it's asmall silver box fastened to the steel panel.

If you can borrow one to test it could save money.

 

[ardi4nto]

I have same problem with your car

Yess... I have same problem with my 1UZ-FE engine ex Soarer....
If i start the engine sometime engine drop & go off (like fuel pump go off)....for few times.
but if the engine already running there no problem again...
But it not happend every time......so I confuse what parts I must check because that problem came around twice a week...

rgds,
A N T O

 

[LexTite]

Was just reading the post, i have a 90 ls and about once a week it'll do on a very cold start, i dont have to rev it to 3000, but i have to give it some gas to about 1000 until it wil fly on its own. I only crank it about 4-5 times a week so i thought it was just a result of that.

i know its not my pump because my rear deck is removed and i can hear the pump continuesly running during the stall. had a legend once that the fuel pump relay worked when it wanted to. Thats bad

But also check one of ur coils. when one went out on me it did the same thing plus sounded the same way. I happend to test that with a mutimeter (never thought to test the fuel pump ecu) and it was bad 20 bucks later it was purring again. I believe the coils fried after melting my platinum fours that i wasnt supposed to be running while spraying, remember to follow forum advice.