Here's the deal:
I have a 92 laser AWD 5 speed that seems to be lacking the power it should under boost. I have been fighting this problem for over a year now and here is what I have done.
- First I replaced the plugs with a new set of NGK bpr6es since it felt just like a bad set of plugs(I have experienced this enough)
-The car overheated a long time ago and lost a bit of vacuum so I assumed it was the head gasket since it was overheating all the time now. I replaced the rad because I broke the top hose off and the new rad cools it fine. I did a boost leak test and found my intake gasket was leaking badly so I figured that was it. I recently rebuilt the motor but when it went back together it still had the problem. Turns out the block was probably warped and wouldn't seal with the new head(60 psi in 2 cylinders).
- A friend of mine was selling a car identical to mine so I bought it(only 155000 kms on it) and swapped the motor out. The new motor had the timing belt replaced badly(by Canadian tire from what I read in the receipts in the glove box) and the timing was out a tooth. I fixed it, replaced the ISC with mione(car wouldn't idle below 1800 and would fluctuate). Now the car idles better than I thought a DSM could, the turbo works great, no smoke at all and never stalls. Only problem is it is still down on vacuum(only about 16 in/hg at idle) Boost leak test on the new setup proved perfect with only a slight leak at the TB seals at 20 psi. Base timing is set at 5 deg, idle rock solid at 750 but has a sporratic slight miss every now and then.
With the new motor everything works great except it still seems to fall on it's face under boost. It starts to pull good, but as soon as it starts to get fun, it just sort of flatlines... just like a bad set of plugs would feel like and these are another new set of NGK's. I tested the plug wires and tried 2 sets I have with no change in the problem (haven't ruled out the wires yet though)
Logger shows everything to be pretty normal, a little bit of phantom knock but absolutely no knock at all on hard pulls in higher gears when it is acting sluggish. O2 readings are high, around .96-1.01 v which is really rich so I am ruling out a lean condition. I have a 190 lph pump and a new fuel filter.
Swapped out the MAF today for the other one I had... no difference.
So my dilemma is, the problem is still there and even though I have fixed many problems that should have been causing it, it persists. I used all the electronics from the other car(coil packs, sensors etc) so I don't think the problem would be exactly the same if one of those things were suspect. The only thing left to swap is the ECU(which I just pulled out of the other car now and found it to be an EPROM! Woo Hoo!).
Any thoughts? Or any logger readings that would help? Trims were all around 95-100%, tps smooth, knock nearly non existant. I tried 2 sets of injectors in the other motor and this motor had a set so thats 3 sets of injectors that made no difference. I guess I could have 2 faulty coil packs or my wires are weak(not totally misfiring but maybe weak spark).
Going to do a compression test on the new motor but I don't think it would idle so perfect if it was low enough to cause a problem.
Is there a problem that would cause this sluggishness AND my low vacuum condition? Like I said, boost test was fine to 20 psi and would hold pressure pretty well. Took quite a while for the 20 psi to bleed off.
Sorry for long post, just trying to give as much info as possible as I have been reading through a lot of old posts about this topic and they all point to plugs/wires/coil packs/boost leaks.
