Car doesn't want to rev!

Pimpin Dsmstyle · 05-09-2006

Problem - Car idles on it's own and will rev normal until only about 2k RPMS. It is extremely hesitant past that. The stock boost gage is reading 14psi and the car is on jack stands. The after market boost gage reads no boost. I know the stock gage is POS but I'm guessing that it's showing a problem since it should not pass zero in neutral. I think it could be the TPS.

History with the car - We rebuilt the bottom end of the motor. It's a 91 TSI awd turbo talon. It has a MBC, volt meter, "a/f gage", boost gage, 2.5 inch exhaust. The car is mainly stock. The timing belt is correct, but the ECU timing isn't set. Regardless to if the cas is inverted or anywhere it can possibly go, the same problem exists. I know the timing needs to be set but I've never done it before and I don't have access to a timing light / alligator clip at this time. I've swapped both the CAS and coil pack off a perfectly working dsm and the problem didn't get any better.

Berda · 05-10-2006

check the mass, and boost leaks

Pimpin Dsmstyle · 05-10-2006

Quote:

Originally Posted by Berda

check the mass, and boost leaks

If I knew how to use a volt/ ohm meter or read schematics.. I might have some luck there. But since I don't - pretty much shit outta luck. If you need anymore parts I have - im sure we could arrange something

Pimpin Dsmstyle · 05-10-2006

There is a lot of popping / back firing going on also. The plug that goes into the idle motor thing makes weird crackling sounds when the car is in the on position.

tim · 05-10-2006

Is the ECU a known working ECU?

**Kracka** · 05-10-2006

Fix what you know is wrong before anything else. Get up to an auto parts store and buy a timing light or find someone to borrow one from. If that doesn't work check your plugs and wires, after that do a boost leak check. Check out that crackling sound too, DSM's make lots of weird noises when first put in the "ON" position, but if it continues more than a second or two you have some issues. Like noted above, also confirm your ECU is good.

At-Least-It's-An-Evo · 05-10-2006

Is the mas plugged in?

Pimpin Dsmstyle · 05-10-2006

Quote:

Originally Posted by At-Least-It's-An-Evo

Is the mas plugged in?

Yes. I'm going to try a different one tomorrow.

The ecu showed no signs of any damage. It worked when the timing belt broke 2 years ago. I took out the ECU when I got it to check if it was an EPROM and there I didn't see any leaky capacitors and it didn't smell like fish.

My brother decided to try take out the ECU with a screwdriver and snapped 2 of the clips. They are in securely but I can't compress the clip to remove the plug because there is nothing there. That is a real kick in the face. I have a spair ECU at my house too. Suggestions? Besides kick him in the teeth, I already did that.

**Kracka** · 05-10-2006

I bet your timing is messed up since everything was fine before you did the t-belt job. Double, triple, and quadruple check all the timing marks line up and the set the base timing to spec.

Pimpin Dsmstyle · 05-10-2006

Quote:

Originally Posted by S2kracka

I bet your timing is messed up since everything was fine before you did the t-belt job. Double, triple, and quadruple check all the timing marks line up and the set the base timing to spec.

The tbelt snapped on the previous owner. We have checked and re-done the tbelt. No change.

I just swapped MAF's and got no change. I will double check the timing belt a couple more times tomorrow. One time when we checked, all of the notches were good but the cam gears were SLIGHTLY out of line. It certainly didn't seem like it was off a notch, but we re-did it and got the same results AT FIRST. Then we proceeded to run the car looking for other things to fix 'till we figured that out. Once we were ready to do the belt again, we lined up everything and the weird thing was, everything lined up perfectly. I'm assuming the tension evened out and everything came out fine. Like I said though, I'll check again tomorrow. The timing belt takes like 15 minutes.

Tomorrow I should be able to use my buddies working TB / TPS. He also has a timing light. I need to figure out how to ground out the ECU though. I don't know if anyone will have alligator clips. I looked at the ground plug and it looked like it only had 1 metal prong and a purple prong. Is that right? This is the plug that has no plug-in besides the "plug cover" that goes into it to prevent it from accidentally grounding out.

Pimpin Dsmstyle · 05-10-2006

Could slightly bent valves cause a problem like this? I bought the head used and everything looked fine. I'm still going to do all of the other things on my checklist, but it's starting to look like it could be the head. The car smokes alot and backfires frequently - the smoke is grey. Now I am going to do a compression check as well.

Pimpin Dsmstyle · 05-11-2006

different ecu fixed the reving issue. Smoke didn't go away. Decided to take it around the block - wouldn't boost and it died right before I got into my driveway. It seemed like a clean kill. Haven't determined what happened yet.

**Halon** · 05-11-2006

Good job on fixing the revving. Now you can't make boost, and you're still smoking. Hmm I guess I know what I'd be checking next!

slowbubblecar · 05-11-2006

I'd do compression and a boost leak tests.