i start my car and it starts for like 5 seconds then dies but withing that 5 seconds the car seems normal, you can rev it and everything. so im wondering whats wrong with it? maybe a vacuum leak? but i can't find the sorce, air pump is removed if it has any thing to do with it and i have to jump start it so battery isn't that good, could it be the alternator? or spark plugs? thnx

 

sounds like the idle is just set wrong and the initial high revs that happen normally when you start the car are what is keeping it running. When you start it it should rev up to 3000 rpm for roughly five to ten seconds then work it's way down to a decent idle as the engine warms up. If your car is idling normally for that first portion then I would geuss the idle is just set too low and you should try having some one manually hold the air baffles partially open and see if the car stays on.

 

dad had same problem - turbo hose under air pump had fallen off when he was working at the fuel pump resistor relay.

 

Try putting a jumper wire in the fuel pump check connector located near the passenger side front strut tower, and see if the car will start and run. It sounds like your pump stops pumping when the ignition switch is released from the "start" position.

 

k ill check it out today thnx for the quick help guys

 

Check out the AFM if nothing else obvious is wrong...

 

Yup..

#1 reason for an FC to start then stop after a few seconds is either

A LARGE VACUUM LEAK

OR

AFM PROBLEM.

Shall I get into the mechanics of the entire thing?

 

how do i check the afm? do i just replace it if its not working? or adjust it? what is a afm?

 

Guys with more experience can correct me, but I think a faulty AFM is not allowing the fuel pump to run. You can check that very quickly by putting a jumper wire in the connector I mentioned earlier.

 

The AFM door switch (which is what you'd be jumpering a ground past) is the problem maybe 90% of the time, if it is in fact the AFM giving you the problems. The other 10% seems to be something else in the AFM that's broke. Guesstimations based on what I've read on the forum over time...

If jumpering the check connector works, it's definetly the AFM, or a short stretch of wiring that's open leading to the AFM...

The FSM has test procedures to verify a faulty AFM...

 

i played around with my BAC screw a little the other day and started it and it idled intially for like 5-10 seconds then died. It had never done that before, so I dialed it back and it doesn't do that anymore.

 

ok i checked out the car a little bit more and the car stays on if you keep it over 3 rpm but if you keep it under its going to die or maybe its dying slowly but i have to keep gasing it to it stays above 3000. so maybe not enough gas or is it still the fuel pump problem becuase i don't know how to do that jumper thing for the fuel pump.

 

Sounds more like a vac leak now.. Did you happen to do any work to the engine before this happened?

 

Yeah vac leak. Check all your hoses etc.

 

Check your injector o-rings and grommets also, my car was idling horribly due to them leaking in unmetered air..

 

no i didn't do any work, but i just bought the car, and it didn't have the intake and intercoller pipping but i put them in, and also i noticed the intercooler is kind of screwed off so i guess the guy before me took it off before to do something. so definitley vacuum leak right? thnx alot for the help

 

same here iam geting fuel but the car wont stAY on ??? do my plug wires have 2 be on the rite stop to aleast turn on , IT USE 2 STAY ON IF I KEPT THE GAS ON BUT KNO IT JUST TURNS ON FOR LIKE A SEC BACK FIRES AND TURNS OFF.?????HELP ME GUYS WHAT DOES IT SOUND LIKE ????

 

well i thought i posted it but i guess i didn't, i took the car to my mechanic because i coulnd't find any vacuum leaks and he ran a compression test and there was no compression, so i guess its because my motor is blown, 12akid, sounds like you have the same problem as me i guess you should do a compression test first.

 

okay Im going to expand on this, Im having that same idle problem except my engine is bareblocked andIm on my second tps and afm. I even had someone come do the timing and it just keeps running like ****. The first day I had it running, ( earlier this week, maybe saturday) it ran okay and idled at 3k. now it won't idle and making **** for power. I just cant figure it out, im going to take the top end off and search for vacuum leaks but if thats not the case I dont know what it would be. It also backfires, and is really loud. Ive searched and ahhh I need help!!

its an 86 gxl with an 88 gxl motor/tranny. the 86 had an engine fire so the harness is patched from the 88.

any help so greatly appreciated...I would pay someone but noone here likes rotaries.

thank you, dane.