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

 

[freeman 188]

I had a simular problem on my 91 laser and couldn,t figure it out until I pulled my wires of and saw that the wire had burn,t of inside where it plugs onto the coil .these were 8mm wire to ,so I would check that.

 

[Srt4RacerDave]

Which wires are you talking about?

 

[freeman 188]

Which wires are you talking about?

your plug wires

 

[tkelly27]

Pull the CEL codes and check for boost leaks.

 

[Srt4RacerDave]

I Might add that I found my o2 sensor was unplugged. Im not sure how long it was unplugged but either way nothing improved when I reconnected it.

as for boost leaks...I checked to make sure my intercooler piping was secure and that my Turbo XS boost controller was secure. All of that was good.

 

[tkelly27]

Not good enough.

 

[madtech707]

your plug wires

I second that! I just recently had to replace my old spark plug wires for sputtering going into boost. Try checking it at night, since you says it misses when you rev it at 2200rpm pop your hood and rev it up. If the spark is jumping off the wires you'll see it at night.

 

[spaugh]

I would do a boost leak test. Just because all looks well does not mean that all is well.

Are you getting any black smoke when trying to rev.

 

[jwcardy]

Have you tried your fuel pump? Check that then get back to us. A friend came to me with same problem. I swapped the fuel pump and prob solved!
-wes

 

[freeman 188]

one more thing I thought of ,my 92 awd had a problem simular to yours also ,changed the ecu and all is well, old computer I pulled apart and it had leaky caps .

 

[63tuner]

i have the same problem, i suspect one of the injector is clogged or leaking. i am going to change the injectors or injector seal because i smell fuel when pushed the throttle at about 2-3000 rpm.

 

[Srt4RacerDave]

For the plug wires, I have heavy duty coated Nology wires. They are fairly new. Not saying something couldn't be wrong with them, but I thought I'd throw that in there.

Have you tried your fuel pump? Check that then get back to us. A friend came to me with same problem. I swapped the fuel pump and prob solved!
-wes

Any way I could test that? I'm use a Walboro 255 fuel pump.

 

[91TsiTalon]

My suggestion to you would be to go out and invest in a Haynes Manual for your car.
It will tell you everything you need to know when it comes to checking things on your car.

-Dan

 

[Srt4RacerDave]

My suggestion to you would be to go out and invest in a Haynes Manual for your car.
It will tell you everything you need to know when it comes to checking things on your car.

-Dan

I have one actually. It's been a pretty big help. But It hasn't been able to answer my questions here.

 

[madtech707]

Did anything significant happen leading up to when this problem started? Just wondering.

 

[Srt4RacerDave]

The only thing that happened out of the normal is that my alternator belt came off and got shredded up a few days ago. I replaced the belt and tightened it back up.

I should also add that after I turn the car on, I get an idle surge untill the car warms up a bit.

 

[tkelly27]

Again, CEL codes and a boost leak test. Wiggling the couplers isn't going to tell you jack about boost leaks. This sounds especially like a boost leak with the surging and that when you hit where you could be making boost the problems start. I've seen couplers with a slit in them that closes under vacuum and are undetectable unless you are putting compressed air into the system.

In my experience, these cars will most often throw a CEL code when something is wrong, especially if it happens at a specific RPM. Just because the light isn't on, doesn't mean you don't have any codes.

When my car randomly acts funny, it's the connector to the coil pack. The wire was short from the factory and the connectors do not hold on so well in 18 year old cars. I do get a CEL code from that, and the light does not stay on.

Update your profile too, please.

 

[drivemusicnow]

I think that we should write up a diagnostic "order of likelihood" type of thing for these situations... I don't have time to right now, but I'll give you some good ideas of things to look for:

First, Pull the plugs after you have this condition. You should be able to tell by the plugs whether the car is running lean or rich, or if you have an excess of unburnt gas.

I'm assuming at this point that you have properly checked all of the following:
All charge air pipes, MAF, and plug wires:

If it is lean, than you aren't getting enough fuel. Things that can cause this:
Fuel filter (try replacing, unless you've already done this recently)
Fuel pump (going badly etc, check fuel pressure if possible)
Injectors (signal, or physically bad)

If all of these things check out okay, you'll have to move onto some other things like the ECU, injector wiring etc.

If there is unburnt gas, you have an issue with the spark
Try diagnosing the ignition systems using a manual like the haynes (checking voltages/resistances), or just swap out the coil pack, resistor pack, that other silly thing that a triangular plug by the coil pack etc

If this all checks out, it's possibly the ignition timing is off, check the Cam position sensor, ECU, etc.


Let me know what you find out. (I dont' think it will be rich, but if it is, check fuel pressure.)

 

[Srt4RacerDave]

I do have a CEL on but every shop I call within...say..100 miles cant code the old computers. All the problems occur in neutral as well. I've checked the MAF already ( swapped with a friends) And have a good set of plug wires. I'm not running lean, im on the rich side. Im checking these things as you guys throw them out there. I do have a set of the stock injectors that I could try swapping on.

 

[jwcardy]

find a buddy with a dsm and see if they will let you swap fuel pumps to try it out...my money is still on the fuel pump...
-wes

 

[Srt4RacerDave]

Will do. Can I just find someone with another 255 like mine? Im getting my car coded (hopefully) tonight so I'll post which code I get up then.

 

[drivemusicnow]

Right after it's backfiring and such, pull the plugs and tell us what you see.

 

[spaugh]

If your running rich more than likely it is a boost leak.

 

[Srt4RacerDave]

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.