TraviZ

iTrader: (2)

after a long journey, hot or cold, i fire up the car and it dies insantly. however, if i keep the throttle barely open, it runs fine! even drives fine. ive played around a bit, unplugged the maf, no difference, unpluged iac, tps, esc, iat, but one at a time of coarse, none of which made a slight bit of difference. then i finally found something. i unplug the vaccuum line running to my afpr, and i got it to run on its own.. very crappy.. 400-500 rpm at max and actually it did die after a few minutes however. while running, if i tried to plug the line back into the plenum, or put my finger over the new "leak" in the plenum, it would instantly die. this leads me to either a bad iac not letting air in, or a bad afpr which isnt providing adequate fuel pressure for idling.

what else could it be, this is a fairly new holley afpr for the stealth ram (2 months old)

help me out im at a dead end.

vindeezl

iTrader: (2)

Oh No!

Not the pink fairy!!!!!!!!!!!!!!!!!

Damn Holley AFPR ARRRRRRRRRRRRRRRRRRRRGH!

Try cleaning out your IAC first bro

CrazyHawaiian

I just got done fixing an idle/stall problem and boy did I learn alot about troubleshooting. Best tool you can have is a scan tool because you can see alot of the sensor inputs, but if you dont have one you can still make progress with a digital volt meter.

Since you kinda narrowed it down to something with the AFPR I would test the fuel pressure to the rail, hook up the guage and turn the ignition on, should be around 43-47psi or something, then drop about 3psi max. If thats good then you know the pump and filter are good you gotta move on to the injectors. A search would probably be needed to get specifics, haven't had to test these myself, but they are testable via the DMV/DOM and you can also do the visual check to ensure they are spraying right.

If the fuel system checks out then check the vacuum with the guage, I believe the correct reading should be between 20-22hg but best to consult a manual of some sort (chiltons, etc). Prove out vacuum and move on from there.

Next on the list would be something related to ECM or one of the sensors that isn't immediately obvious. I would pull codes with a paperclip and make sure its clean. Then I would check the timing with the ESC disconnected, make sure thats correct. Definately remove the IAC and TPS and clean the carbon out, you can test the TPS with a DVM too, should be .54v or close at idle (throttle closed). Gotta build a wire bridge to test that one. I think the IAC pintle needs to be 28mm away from the flange before re-installing. There are probably tests for the other sensors I dont know offhand, knock and 02, etc, etc.

My problem ended up being a bad TPS and IAC but I was getting no SES codes. They were dirty and giving bad outputs, but they still were working (kinda) so no codes. Even after cleaning, they were still bad, had to replace both with new sensors. And I didnt have to reset the minimum idle, IMO you should never have to, but to each their own ...

wills83z28cfi

Thanks for the info guys, I was with Travis last night when his car started to crap out on us. I know he already looked for codes, none found and never got a check engine light. I also know his car runs fine once you start driving, I would think if it's a dirty fuel filter or bad fuel pump he would loose a lot of power and top end. But he hasn't, car still runs like it always has. Hope this helps a little, I know Travis won't be able to post again until tonight. I will let him know what you guys suggest when I see him today at work.

TraviZ

iTrader: (2)

thanks for the help gentlemen, the damn problem fixed itself a day later... i think it was prolly a clogged iac that unclogged itself. im still gonna take it apart and clean it though to prevent this issue again. thanks!

vernw

iTrader: (2)

Don't rule out a bad or temporarily stuck IAC.

I had an IAC that quit working. THe ECM data logs only report what the ECM TOLD the IAC to step to. It is not reporting whaere it actually is!

Took a while to figure that one out. But it was definitely the IAC, and replacing it fixed the problem.

Just something to think about. If it was stuck, it will get that way again most likely.

vindeezl

iTrader: (2)

I've got a spare IAC you can try out if you like TraviZZZZZZZZZZZ

Another thought, could you're injectors be leaking a tad. Maybe all that super PSI from when you were running that laughing gas.

TraviZ

iTrader: (2)

i doubt it i ran maybe two bottles on these NEW injectors and a leak wouldnt cause the engine to just die without hesitation, i know this from my previous injectors that did die due to being stock from nitrous lol