Out of ideas...

[Srt4RacerDave]

I have a 1991 Eclipse GSX. I have most standard bolt-on mods including intake, exhaust, 16g turbo, fuel/water pump, injectors, new headers, my battery is relocated in the trunk. Starting yesterday, as soon as I rev the car to about 2200 RPM, it starts backfiring horribly and will not go into boost. It almost sounds like its bouncing off of a rev limiter. It will go into higher RPMS, but backfires all a long the way. I;ve tried a few things that some friends recommended such as replacing my spark plugs, checking the ignition plug is in securily, I swapped my MAF out with a friends to make sure my MAF didn't die on me, checked the timing belt for skips, cleaning the throttle body and idle control motor, tightened up the bolts on my exhaust manifold to the turbo and engine, and tried resetting the computer all a long the way. Does anyone have any ideas on what could be the problem? I'm seriously out of leads here and will greatly appreciate any help. If you need any more information let me know. Thanks

 

[1stGenTSi]

I do have a CEL on but every shop I call within...say..100 miles cant code the old computers.

You can do it yourself
ECU Code Checking

Ill be getting the CEL code tonight. Im waiting till it gets dark out to do the plug check. In the mean time I've been checking for leaks. Checked the intercooler piping, the intake piping to the turbo, the exhaust manifold to the turbo.

Sounds like your doing a visual boost leak test, which as already stated is useless. Although a boost leak is not going to cause the problem your having unless it's huge. Build a boost leak tester.

 

[tkelly27]

For future reference:
ECU Code Checking

I'll say this one more time. You need pressurized air. I've been there, trust me. It blew my mind when I saw all the leaks I had even though I went over everything a million times.

Damn, beat me to it!

 

[Srt4RacerDave]

I'll do a boost leak test, but I got my CEL codes. I got a code 12 and a code 14. My MAF and my throttle control sensor. My MAF is fine, but I have a 1g to 2g conversion that required soddering some wires, which I then taped over. Maybe one of the sodders broke or something. So I'm going to check my wires tomorrow. As for my throttle control arm, the only way I see to fix that is by buying one for 105$ from autozone. Do these problems some relevent to my problem?

 

[tkelly27]

If it's throwing a MAF code, it's going to run shitty. Did you compensate for the 2G MAF? Throttle sensor, try unplugging it and plugging back in. If not, check the resistance I guess. Get one from the junkyard or Craig's list. Parts stores suck.

 

[Srt4RacerDave]

If it's throwing a MAF code, it's going to run shitty. Did you compensate for the 2G MAF? Throttle sensor, try unplugging it and plugging back in. If not, check the resistance I guess. Get one from the junkyard or Craig's list. Parts stores suck.

I tried unplugging and reconnecting the sensor. As for the MAF, as I stated earlier I swapped mine out with a friends and still had the same problem. Which makes me look towards the actual connection. Ive had the 2g conversion MAF in for a long time with no problems (until now) with it

 

[eclipsetuner_21]

I had a similar problem with my 91. Can you hear your 255 wine?? Mine wined and I read some do, but come to find out my gas tank had rust in it and it had clogged the sock on the pump and caused it to stutter when reving and i would be lucky to get 1 or 2 pounds of boost.

 

[Srt4RacerDave]

I had a similar problem with my 91. Can you hear your 255 wine?? Mine wined and I read some do, but come to find out my gas tank had rust in it and it had clogged the sock on the pump and caused it to stutter when reving and i would be lucky to get 1 or 2 pounds of boost.

Yes I can, but I've always been able to. That will have to be something I check today

 

[dlb21]

I would start with the fuel filter... has it been changed recently....what about gas what type of gas is in there... you could try replacing it though that is a long shot.... just some suggestions

 

[Srt4RacerDave]

Re-did the wires that connect into the MAF, and re sodder'd them. We found a very lose clamp on home hosing after the MAF, so we clamped that up. Still having the same problem =/

 

[drivemusicnow]

Sooo uh..

What do the plugs look like.


Here is a lesson in diagnostics. The first thing you do when you have a problem is figure out what that problem really is (by pulling the plugs)

That limits the options basically into categories. Once you have the category of problem, you can then figure out which components might be causing it. Then you go in order of easiest and most likely and you end up with an answer. Stop just jumping to swap out/ mess with components. It will normally take longer, and is inefficient.

 

[Srt4RacerDave]

The plugs had some deposit on them, so I got some new ones and gapped them correctly. As I understand having deposites on the plugs means I'm running rich?

 

[dlb21]

THat is corect, build up on the plugs usually indicates a rich mixture though that depends on how much. Build up is normal part of wear and tear, a white gray will indicate a lean mixture. What plugs did you get and what did you gap them to??

 

[Srt4RacerDave]

I had the NGK plugs for higher boost. They are only 2 months old or so, and had the pitch black deposite. They were gapped to 32

 

[tkelly27]

Profile says you're running an AFC too. That could be wired improperly or coming loose. Have you done the boost leak test yet? I'm pretty sure it will throw a code if you have a bad enough one.

 

[Srt4RacerDave]

When I put my friends Vr-4 MAF into my car, it actually runs! It built boost up to 18 psi, and was driveable. It was throwing two MAF codes (different from the original codes), but I think that's because the Vr-4 MAF has different MAPS and programming then an eclipse one.