Rev...then stalls

[CatchMe]

Hi all! Im having a stalling issue when I free rev the motor, the revs come down and it stalls or almost stalls. I have done so much to try to cure it over the past couple weeks with no avail. I've rebuilt my tb, changed FAIV, no boost leaks, fuel settings are correct, etc...
The motor is a 6 bolt with no balance shafts and a ACT light weight flywheel but it never stalled with my old turbo/ setup with the light flywheel so its not related to my stalling problem.
I changed a few things before this problem started which include: SBR GT12 turbo, Dejon 3.5inch intake pipe, rebuilt tb with new gaskets, removed A/C, new spark plugs BPR7ES @ .028, PLX wideband (removed rear 02 sensor). DSMlink says im getting .28 g/rev which is correct airflow at idle. The only thing I can think of is right after I started the car after I did the install of all those parts above, it ran out of gas in the garage. Maybe the fuel filter got a little clogged of something? The filter is brand new (less than 300 miles on it). One other thing is that after I rev it, if I try to keep it from stalling by bliping the throttle a bit it almost feels like it stutters like it has too much gas and I have to burn it out. After bliping the throttle it takes like 5 seconds of fighting with the idle to get it to idle on its own. My ISC is working but im not sure if its working correctly...i've seen a couple people that have reported bad ISC's that still test fine. Any ideas would be great. Thanks!

EDIT: I've done COUNTLESS hours of searching

 

[Bjeezy01]

This might sound stupid, but it's free...unhook the batery, then hook it back up, this will reset all the sensors, MAF. Sounds like an Air/Fuel issue. I had a simular issue that was fixed with this free mod, nothing to loose, give it a try, and let us know how it goes...

 

[oddrob]

You changed the intake, did you change the BOV routing? Is it still routed back in like stock? First thing that comes to mind.

 

[oldman]

I've been fighting the same issue for a while now but mine only happens when engine warms up. I've done everything you've mention which led me to believe it's my ECU again, second one in one year. I went on the taboo website to see if I've missed anything and this is what I found,

http://www.taboospeedshop.com/diagnostics.htm

The chart shows two possibilities for idle continuation problem under warm conditions, AC switch and throttle body air hose. I know for a fact that my TB is not leaking so AC switch is the only thing left. My AC is not removed but I've removed the line that goes from the condenser to the driverside of the engine bay due to FMIC install. I've also notice the AC switch does not turn on the spal fans anymore as I used to turn them on using the switch to test them. I will be doing some research as to how to fix the switch and why it would affect my idle. I will let you know if that solves my problem, as soon as I get to it that is, it's freezing outside.

 

[CatchMe]

Thanks for the replies everyone. I have the bov recirculating so that isnt an issue. I've reset the ecu a couple times while working on the car also and that didnt help. The stalling occurs all the time - hot or cold engine temp. The ECU has recently been socketed to be used with DSMlink so I dont believe the caps are leaking. I have a feeling that it may turn out to be a fuel issue. That is intresting about the a/c switch - although my flex-a-lite fans come on when I push the a/c button after the car is up to operating temp. I believe that is a logable value in dsmlink. I'll check that out this weekend. Thanks for the link too - very helpful.

 

[red_rs]

i have the same problem in my 90 laser turbo ive tried all little things but havent been able to solve it, the next thing im gonna try is switching the ecu, maf and tb gaskets and check all of my vacuum hoses, it didnt start doing this untill i rebuilt my motor, its kinda wiered if u ask me. post back if anyone knows anything about this problem. thanks

 

[CatchMe]

i have the same problem in my 90 laser turbo ive tried all little things but havent been able to solve it, the next thing im gonna try is switching the ecu, maf and tb gaskets and check all of my vacuum hoses, it didnt start doing this untill i rebuilt my motor, its kinda wiered if u ask me. post back if anyone knows anything about this problem. thanks

Sorry, I never updated this thread with my solution.

I ended up switching to a 3in GM MAF/MAF translator setup for air flow metering. This completely solved my issues. Keep in mind my stock MAF sensor was working correctly and was not hacked at all and I had no boost leaks (held 20psi as tested).

I've seen other people have this stalling issue with stock MAF sensors and dual BB turbos, such has the SBR GT12 that I was running when I encountered this problem. If you are running a dual BB turbo, I'd suggest going with a GM MAF setup. Good luck!