cleaned iac, replaced bad coupler... still stalls

[FlamboyantStealthTT]

i posted this on the other forum too but anyways... i just recently cleaned the iac following stealth316 procedures and i dont think i messed anything up. i put everything back on tightly too. after i put back the iac the car started but the idle was low on cold. i pulled it out of the garage as it started to warm up it stalled. i then got the car back in the garage and saw the bad rubber coupler that connects the ypipe to the tb, so i replaced that with a silicone one and tbolt clamps... now on cold start ups the car starts up and idles at 1200 rpm's ONLY FOR A ABOUT A FULL SECOND, then it stalls...

is there anything else i can check? fuel related problems?? i just made a pressure tester havent gotten an air compressor yet im going to borrow one from my friend tonight hopefully... but besides doing the leak test, what else could it be and what can i do? or was it most likely i messed up my iac somehow??

[toddrs93]

Are you running an open atmosphere BOV? I have seen time and time again these ebay BOV's that leak so bad they cause the car to stall all the time. Is the MAS OK and plugged in?

[blindmist]

You can quickly figure out if it is an intake leak by just unplugging your MAF. You will get a check engine light, but it should stay idling if you have a leak that is causing the stall. And I must say about the eBay ones, I have had a $40 eBay knock off of the RFL 3SX sells, and it has lasted me 3 years and still holds pressure up to 25psi. I could have just lucked out.

[Tool Man]

Cleaning the IAC doesn't always work. I'd say 50% of the time if that much. It probably needs to be replaced.

[CoreyB]

Did you have problems before cleaning the IAC ? Will it stay running if you give it some throttle ?

[FlamboyantStealthTT]

i had an ebay bov. replaced it with the blitz dd bov. the blitz attached to a hose and the hose goes to the ypipe(dnp). didnt like the design where the bov gets clamped on so i switched it to dejon's ypipe with the welded hks flange. so now i have an original hks bov. the bov have a brand new o-ring to the flange too.

yes i plugged the mas after putting everything back on. ive checked to see if the iac is functional after i took it off, followed everything like stealth316 says. the resistance is perfectly fine.

[CoreyB]

Make sure your coolant temp sensor is plugged in.

[FlamboyantStealthTT]

i just reached my hand underneath the intercooler pipes it seems the coolant temp sensor is plugged in. i used my finger to push it in to see if it will go/move, the connector is on there pretty good.

[toddrs93]

You can quickly figure out if it is an intake leak by just unplugging your MAF. You will get a check engine light, but it should stay idling if you have a leak that is causing the stall. And I must say about the eBay ones, I have had a $40 eBay knock off of the RFL 3SX sells, and it has lasted me 3 years and still holds pressure up to 25psi. I could have just lucked out.


thats impressive

[FlamboyantStealthTT]

ok so i unplugged the maf, it stayed on a bit longer. i would say about 4-5 seconds and then it stalled. with it plugged in it stalls right away... do i have a leak or no?

[Atrosity]

Any CEL?

I suggest replacing it, you can get an IAC from autozone for less then 90.

[blindmist]

ok so i unplugged the maf, it stayed on a bit longer. i would say about 4-5 seconds and then it stalled. with it plugged in it stalls right away... do i have a leak or no?

Probably, but something is still killing it. It should at least idle with the MAF unplugged and stay idling.

[FlamboyantStealthTT]

nope no cel

[CoreyB]

I asked this earlier but will it run by feathering the gas pedal. If it does this could point towards the TPS being bad or set wrong.

[FlamboyantStealthTT]

so i plugged the air compressor in. and the gauge on it reads 0 but air is being pumped in... i think i need to pull off some vacuum hoses and plug them. theres a hose from the intake to pcv, and intake to valve cover... which one do i take off and plug??????

and i live in a complex i cant press on the gas pedal the garage is built with a 2 floor apartment and its under someone's home. theres a lady live above the garage. everytime i drive i need to pull it out to warm up the car.

[FlamboyantStealthTT]

anyone?

[CoreyB]

How exactly are you doing the test ? You aren't trying to use a tank less compressor are you ?

[FlamboyantStealthTT]

its a portable 12v air compressor for car tires

[steve]

Little compressors don't have the volume needed to pressure test when you have anything but the smallest of leaks. You also need to make sure that none of the cylinders are in overlap where both the intake and exhaust valves are open. You have to look at the cam specs to see when the intake opens and the exhaust closes then think about where each cylinder is at those times to make sure none have more than one set of valves open. On the 4G63 about 30* ATDC is good but I haven't thought about if that's true for a 6G72.

These might be helpful even though that are on 4G63's.


http://www.youtube.com/v/KibYz21IMA0?fs=1&hl=en_US

And what a good ISC should do when you turn the ignition on.


http://www.youtube.com/v/l7R3gf7SiAo?fs=1&hl=en_US

[FlamboyantStealthTT]

installed a brand new iac bought from rock auto with brand new gasket... still stalls right on cold start

[FlamboyantStealthTT]

I asked this earlier but will it run by feathering the gas pedal. If it does this could point towards the TPS being bad or set wrong.
today i had a chance to do what you mentioned. i tried giving it some throttle(feathering it) as soon as the car started up but it didnt work. it still stalled... is it for sure to be bad tps?

[CoreyB]

Thats exactly what my car did when the ECU was bad.

[FlamboyantStealthTT]

did you ever get to find the cause of your bad ecu? and did you have it rebuilt? by who?

[CoreyB]

It had leaky caps, I replaced it with a used one of which is dead now as well, the caps on the used one were replaced but the electrolyte wasnt cleaned up properly so is corroded solder joints which eventually shorted.
Why did you clean the IAC to begin with ? When they go bad they will ruin that circuit in the ECU. Have you tried running the car with it unplugged
?

[FlamboyantStealthTT]

stealthee said my iac was faulty. i posted it on 3si when i noticed my idle was right at 1k at all times when warmed up. then i noticed when i let the car warm from a cold start, the idle goes down to 7-800 but idles very rough. and when i drove it the car wanted to stall but i hardly hit any red lights so i was able to make it home without a problem.

running the car without the iac? i havent tried that...

[CoreyB]

Try it, it wont hurt anything. You may need to give it just a little throttle because the idle will be low.

[FlamboyantStealthTT]

there is no throttle response at all right now..... i even tired pressing the pedal almost half way as soon as i start it up and the engine still wont rev up

i'll take a look at the ecu caps tonight. the battery should be disconnected when i take it out right? and btw it doesnt have a cel. when i turn the ignition on and wait for a sec the cel goes away.

[CoreyB]

Yeah you should disconnect the battery.

[FlamboyantStealthTT]

nvm... posted issue in new thread

[MaxClass]

If what your referring to as the IAC is the same as the ISC then go to Jeff Lucius site and do the continuity tests on it before you replace it. This will tell you if the stepper circuits are good. If not you will have nothing but problems until you replace it. Looking for other possible problems before you have made sure that the ISC is good or bad is just a waste of time. Verify what works first. That will narrow down your search to the parts that don't.

[FlamboyantStealthTT]

i believe i have already posted this before, i followed exactly what stealth316 said and tested it. the iac is perfectly fine but someone still recommanded on a new one so i bought a new one and put it on the car. the problem is not the iac...

the problem isnt the ecu either. took pics of the capacitor and other members said my ecu looks fine.