it sounds like a boost leak so start with a boost leak test... as far as the maf-t goes it doesnt eliminat fuel cut its settings are just like an safc.

Ok, yea i thought it would be a boost leak. What about the idle issue, could that be related to the MAF-T settings?

Sounds like a definite boost leak to me, if the boost leak is bad enough too it will F the idle.. Does it pop when you hit 5k then cut out?

If a boost leak is present, that same leak may also be a vacuum leak. That will throw the ecm on the idle too. It is mechanicaly sound? Junk top end gaskets will throw the idle. Does it eat any coolant ? Does the coolant smell funky , like exhaust? Just a thought. Tres..

BLT it first, Also what fuel mods are done? Get that wideband in asap with no leaks. Anyway to log and see what the cars doing?

Check this out too, I had a similar problem that took me forever to figure out when I first bought my car - 89-94 Capacitor Replacement

Just bought the car from a guy who said there is less than 1000 miles on the rebuilt head, and used all new good gaskets. I haven't checked the coolant or anything like that yet, and i don't have a datalogger. I do have the wideband but I have to get the bung welded in first. I'm going to do a boost leak test tomorrow, I did notice today on the side of the crankcase there is a nipple with nothing on it. When I had my SRT I just had a breather filter on there, so I'm assuming the same can be done for the Laser. Also, he tapped into the BOV for his manual boost controller, which I saw in a post was a no no. I'm hoping it's not the ECU, I have a first gen non turbo Stealth, and I had to have the leaky capacitors replaced in that. I also don't know why he had a MBC on it with the stock internally gated turbo. From my turbo knowledge, it's only going to produce the stock 11 lbs correct? Also, would the MAF-T set at all 0's mess with the idle at all? I've got new plugs and wires I'm going to try tomorrow. Also, when I did get on it before it hit what I think is fuel cut, it did sound like a lot of rushing air, but I couldn't really hear the turbo spooling that loud, but it was spooling. I'm betting money on a boost leak.

Run a vacuum hose off the side of the crankcase breather to the nipple on the intake pipe.

If you have 450cc injectors then all zero's on the maft should be fine.

Our stock turbo's have a wastegate actuator, you can raise the boost with nothing but a mbc.

And I have my mbc T'd off the bov line because I don't have a nipple on my j-pipe. It's not the best place but it's not going to do any harm from my experience.

IC Pipe Tester - In case you didn't find anything good on it.





EDIT: VFAQ Site - Visual Frequently Answered Questions is your friend

A boost leak usually doesn't make the car feel like its hitting a brick wall. Fuel cut under full throttle feels similar to a misfire. I'm betting its old plug wires or spark plugs. Been there, done that. Let us know if new plugs (gapped correctly) and plug wires make a difference.

haswesley said:

A boost leak usually doesn't make the car feel like its hitting a brick wall. Fuel cut under full throttle feels similar to a misfire. I'm betting its old plug wires or spark plugs. Been there, done that. Let us know if new plugs (gapped correctly) and plug wires make a difference.

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Well it's interesting that you suggest that, because I was also thinking that as well, which is why i switched the wires and plugs last night. I gapped the plugs to .030 and right away the car idled better, but I haven't had a chance to take it out and see how it runs. I'm still going to BLT it and I'm also installing my wideband tomorrow.

To check if its a boost leak issue turn your boost down to about 10 pounds or as low as itll go and if your problem is no longer present, you have a boost leak or your exceeding the limits of your setup so turn down the boost. And for those who said a boost leak doesnt feel like hitting a brick wall? Have you ever hit fuel cut at about 5k+ and boosting, it definitely feels like a brick wall under certain conditions.

Well I changed plugs and wires, and the problem is gone. I also changed one MAF-T setting like suggested on here, aux is 0 base is 2. Not sure if that helped or not, but it pulls great now. The only thing left is the rough idle, if it is sitting it idles fine, but once I drive and then stop again, it wants to stall. I turned the idle up, but I have a feeling that isn't the reason it was idling so low, but it may have been. And the guy said it's only boosting stock psi, which is 11, and that is what it's boosting, so I don't think I have any leaks.

Alright, so a little update. I boost leak tested the car today, and found some. I also removed the vaccum lines and that helped with vaccum. I still have the idle issue. It will idle at around 800 or so, and it almost sounds like it's cammed. The weird thing is that you would expect it to run like crap with it idling so poorly, but it runs great. I removed the boost controller and it seems to be boosting right around 9 or 10 psi with just the wastegate hooked up. Any ideas of what could be the issue with idle?

well as far ass idleing at 800 RPM there is nothing wrong with that its perfect... now if it is ruff idleing then thats a different story but these cars are suposed to idle at 750 + or - 50...