car will not idle with turbo

waldo320 · Post by **waldo320** » Sun Jan 08, 2006 6:37 pm

took the afc off and reset the computer still will not idle at all starts then dies, also to IAC valve the air hose to it is just breathing straight from the atmosphere, could that be a problem?

vrg3 · Post by **vrg3** » Sun Jan 08, 2006 6:38 pm

waldo320 · Post by **waldo320** » Sun Jan 08, 2006 8:13 pm

what would a fix be for that run it to one of the intake pipes, and getting fitting welded on?

vrg3 · Post by **vrg3** » Sun Jan 08, 2006 8:15 pm

Yes. Attach it somewhere downstream of the MAF sensor. Mimic the stock plumbing if you can.

waldo320 · Post by **waldo320** » Mon Jan 09, 2006 4:53 pm

there are 3 1/2" vacum line 2 come of the valve cover and other I have no clue but they all came off the stock intake pipeing curently I have them all T'ed togher could that be a problem?

vrg3 · Post by **vrg3** » Mon Jan 09, 2006 5:08 pm

Yes, that is also a problem. But it's not causing the idle difficulty -- these are actually PCV lines, not vacuum lines.

You need a 3/4" fitting for the IAC valve.

waldo320 · Post by **waldo320** » Mon Jan 09, 2006 5:13 pm

on my way to get that welded in and also converting to a blow through set up

vrg3 · Post by **vrg3** » Mon Jan 09, 2006 5:15 pm

Uh, be sure you think things through when switching to blow-through...

dzx · Post by **dzx** » Mon Jan 09, 2006 11:32 pm

My IAC is connected to the intercooler piping just in front of the throttle body, but since its vacuum at idle, i doubt it's what's causing my problems

vrg3 · Post by **vrg3** » Mon Jan 09, 2006 11:45 pm

What are your problems, Dan?

It's possible that the IAC valve is not designed to ever see a higher pressure at its inlet than its outlet.

vrg3 · Post by **vrg3** » Mon Jan 09, 2006 11:46 pm

Oh wait, that's dumb. At idle on a stock car, its inlet is about 10 psi higher than its outlet.

dzx · Post by **dzx** » Tue Jan 10, 2006 12:48 am

That confused me. At idle my car's rpm's jump around between extremely low and about 750 rpm, sometimes it will die. There are no big vacuum leaks that i've been able to find. Also at around 10psi the car starts bogging down. The pressure will keep building but acceleration is less than at 10 psi.

I changed out the maf and have the jecs sensor on there now and it didn't help any. I pulled the spark plugs and they looked fine. Messed with the fuel control and still had the same problem. As the rpm's go up under load I have to slowly lessen the boost. Right now i'm wondering if when the wastegate opens and dumps, the O2 sensor isn't getting an accurate reading but i dont know. Still hunting...pretty sure its not the atmospheric dump after reading about them on nasioc...

waldo320 · Post by **waldo320** » Tue Jan 10, 2006 2:09 am

ok update converted to a blow through set up moved the breather for the IAC to down stream of the maf and before the throttle body, now it will not start at all so I take 3/4" hose of the IAC and there is smoke comming from it, when i tried to start it sounds like I am choking the engine, so tommorw I will cap the weld off and see if it runs better with just the blow through set up , also i noticed that you can rotate the IAC with the two screws on top clock wise or counter what does that do?

dzx · Post by **dzx** » Tue Jan 10, 2006 2:43 am

moves the electro magnet.

waldo320 · Post by **waldo320** » Tue Jan 10, 2006 7:38 pm

well changed out the plugs this morning and drove my car a few miles boy was that awesome yah new plugs and welding the IAC after the maf, coverting to a blow through set up really helped, now just get the cooling leak stoped and ill be running down the track!!!

dzx · Post by **dzx** » Thu Jan 12, 2006 4:05 am

I managed to fix my problem. For some reason the settings on my safc at -40% that were working perfect for a while needed to be changed to -20%. I think it was because i changed the intake from 2.5in to 3in. diameter.

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car will not idle with turbo