No one has any ideas?

 

Your plug wires could be bad, but I would try gapping the plugs to .032. Some cars tend to run better that way. It fixed my problem, and might do the same for you. Especially if it's from 5psi and up. It doesn't seem to be fuel cut if your air flow is only hitting 600hz.

 

I swapped in 2 different ECUs today and still no change. I will try some more ignition coils and fuel pumps. I will also try changing the gap to .032 but doubt thats the problem.

 

Knock sensor all day long! I had this exact problem. Car idled great and was fine out of boost. But if i stepped on it at all i was lucky to see anything over 5psi. It would cut out and feel like fuel cut real bad but its actually you picking up rpm and the timing being pulled back so far. It seems like you've checked everything but that. Id see if its leaking, got any goo under it and if so deffinately replace it. My car felt like a whole new beast when i changed that damn sensor.

 

I will check it, but it is not showing any knock at all on the logger. I put in a 190 lph walbro fuel pump and its still doing the same thing. I also swapped in another coil pack and different wires with no success. One thing to point out is that the car is a 90 and I had wired in a 91+ ignition system when I was running the AEM ems. The car ran great. Maybe I will wire it back up with 90 ignition stuff. But that doesnt seem like it would matter???

 

did you get rid of your emissions? If so are you running it like the taboo vacuum diagram?

 

Ya there is no emissions on the car, except obviously the cat. The stock fuel pressure regulator is hooked directly to the intake manifold. What is the Taboo method?

 

I had this problem twice. First being my turbo took a crap and wouldn't boost past 5psi. Also I had a pretty bad preturbo exhaust leak which also did not allow me to boost past 5psi, New gasket and retorquing fixed that. Also try checking if your filter is clogged, that can also affect boost patterns as well.

 

I hooked mine up like this. I had mine like this and every time I hit 10psi(no boost controller) the car would sputter. I hooked up a line from the compressor housing to the wga and it works a hell of a lot better and might fix your issue.

 

Maybe the TPS, you said it's showing 0 knock? I thought I will always show a little knock when the knock sensor is good? Look for goo ozzing out of the back of your knock sensor. Do you have an aftermarket boost controller still hooked up? If not you need to leave the stock MBC hooked up unlike in the taboo picture, I still have the line off the turbo and the air flow meter pipe. Everything else is removed and capped and I am stock without emissions.

 

Here is a link to the vac lines removal thread, pretty much remove everything but keep the sotck boost controller/silonoid. I will look how I have it setup tomorrow and post
http://www.dsmtalk.com/forums/showthread.php?t=29105&highlight=emissions

 

The knock sensor is only a couple years old there is no goo coming out of it. But I guess I could try swapping it. The TPS seems to be working correctly, when closed it shows 9% and it rises up as the pedal opens and stops at 100% when the pedal is fully pressed. I have a Hallman MBC and its hooked from the nipple on the compressor housing to the WGA.

 

Alright, looked this morning and on the turbo side I have a line from the waste gate on a T to a line to the turbo intake elbow and from the third connector on the T the line runs to the stock boost control solenoid and the other end of the boost solenoid connects to the air can by the air filter. For the fuel pressure regulator it is a bad idea and maybe your problem to run a line straight from the regulator to the intake manifold I believe I read when I was doing it, instead use the solenoid on the back wall of the engine bay by the brake booster and run a line from the fuel pressure regulator to the upper port on the solenoid, the lower port runs to the intake manifold. Here is a picture to make it a little easier. And for my BOV I have the line running from it to the left port on the intake housing. This is how you are supposed to have it if everything is stock and you have the stock boost controller, not sure about when you have an aftermarker MBC. http://www.dsmtalk.com/forums/attachment.php?attachmentid=8577&d=1278645213 this picture isin't very good and I know there is a better site to check out and a better way to have it setup, read through this thread if you have some time, it's what I used, http://www.dsmtalk.com/forums/showth...ight=emissions .I will search for it.

 

read this
http://www.dsmtalk.com/forums/showthread.php?t=29105&highlight=emissions

 

Here is the real taboo vacuum line page, sorry again for a million posts.
http://web.archive.org/web/20040621102025/www.taboospeedshop.com/emissions.htm

 

Thanks for the help so far, I dont have that fpr solenoid, threw it away 8 years ago lol. My car ran fine then(8 years ago) when I removed the fpr solenoid, it seems like it should now. I replaced the fuel filter with a new one and still the same problem. I pulled the turbo off today to fix the leak in the compressor housing, even though that probably wont fix it, but its worth a try.

 

Well I got rid of all the boost leaks, the one from the compressor housing was caused from an old dry worn out o-ring. I replaced it with a good one from a blown 16g I had laying around. No more boost leaks. But the car is still doing the same thing. I am going to swap my 3" exhaust on and rule out the cat being clogged or not. I cant think of anything that would cause this. Anybody have any more ideas?

 

I pulled the exhaust loose to bypass the cat and muffler, and the car still does the same thing. So I know the exhaust is not clogged. I swear it almost feels like the rev limiter kicks in when it builds around 5 psi of boost.

I will paypal someone $20 if they figure out my problem.

 

i dont think its the fuel being cut out or else your engine will run lean (not sputter) and keep going till it blows your engine. does it happen when you rev? if it does you might have some kind of vacuum leak. of course im not a turbo wiz and im not exactly sure how vacuum hoses work under a turboed system

 

Another update. I wired in the boost solenoid, fuel pressure solenoid, and swapped out the injector resistor pack with a different one. I know the 2 solenoids work cause I tested them with DSM logger. And once again car still does the same thing. I took the car up to 7000 rpms slowly and it will go that high but if I try to accelerate too quickly it cuts out. I almost wonder if it has to do with airflow, maybe Ive had 2 bad air mafs.

What do you guys think?

 

*****Problem solved******

Well I decided to check the wiring one at a time by checking for continuity. I started with the air maf since I suspected it might be the problem. Since I had the pinouts for the stock maf and the ecu, I checked them one by one. When I got to the idle switch(yes there is one in the maf) it was open(meaning no continuity). I was happy cause I guessed this might be the problem. So I wired in a new wire, it checked out ok, started the car revved it and it WORKED!!!!! So I went and drove it and its running like a champ. So apparently this wire is very important, but oddly not important enough to throw a code. This wire tells the ecu that the car is not idling anymore, hence why my car would not boost, the ecu still thought the car was idling and would cut the fuel. So thanks for all the help guys! I am very glad I found the problem.

 

Glad to hear you figured it out, now wait another week or two and another problem should arise considering it's a DSM.

 

Bro my car does this same exact problem but, I don't understand it with deep details like you do. I tried alot of things and nothing worked and I am no tech honestly. I know a few things here and there but, when it comes to wiring stuff and figuring out issues like this i'm lost. Nice!

 

hey how far back did you check? This sounds kind of like my problem. I think im gonna try from the ecu plug to all the pins on the maf. Which color wire was it?

 

I checked from the ecu plug to the maf plug.
Use this for the maf:
http://www.vfaq.com/mods/2GMAF-1G.html

and this for the ecu:
http://www.vfaq.com/mods/ecu-harness-1G.html

 

try turning the boost down all the way then slowly build it back up until it runs like you want it without stuttering