my car has been running extremely rough, it backfires, no power and up until recently it would intermittently go away.

Now the car just runs like total **** all the time. I checked the TPS and that is perfectly fine.

I hooked up some LEDs to the ECU plug to test and see if I got error codes and they don't light up at all. They had worked before and now they don't.

So does this mean my ECU is shot? and if so, who's got a spare one they wanna send me?

 

Really, the ECU's are damn hardy - they really don't go out often.

Does the car idle well?

Are the plugs relatively new and in good shape?

Dale

 

new as of 3000mi ago :-/

and the car barely idles, shakes the whole car

 

I would start by looking for a vacuum leak - a decent size vacuum leak will make the engine have a rough "muscle car" idle that stalls sometimes, and will cause all kinds of problems with how the car runs.

Dale

 

Chk your fuel filter...it might be bad.

 

doubt it, all the lines are brand new

and it 'feels' electrical, it used to go away as you varied the throttle sometimes. felt like a bad TPS would. But I'm looking over the car and checking here on and off so I'll look for some leaks. is there an easy way to go about doing that?

 

apex seal. Pull plugs and do a compression test.

 

brand new engine, all three swooshs when do doing test by ear.

everything is virutally brand new in the car....only like 3000mi old

 

I am having the same problem and I think it might be the ecu also but im not sure. I did all the tests you did except the led test. I could use some suggestions also.
thanks

 

Hey it seems like were all having the same problem someone help us.

 

Check your turbo inlet duct - where the duct attaches to the turbo is prone to cracking, and the leak can come and go.

Dale

 

what would make the car do all that and feel like it is running on 1 rotor... compression is good i already checked

 

brand new and stock :-/

 

Time to check elsewhere for vacuum leaks - intercooler piping, etc.

Get a can of starting fluid, and spray it SLOWLY along the intake path. When the leak sucks in the starting fluid, the engine will rev up and smooth out. Sometimes you can also hear the leak.

Dale

 

Pull the upper intake/throttle body off. Replace the leaking(air)fuel injector grommets at the bottom of the fuel injectors. Then inspect the electrical plugs on the injectors for fraying and shorts, as in one wire in the plug touching the other wire. Usually right at the connector.

If that does not work.....punt.

 

so there is no way to test the ECU before I go tearing the engine back apart?

 

Only way I know of testing the ECU, is to go to the Fuel section of the manual. At the beginning they give you the value that should be found at each and every pin on the ECU when the car is at idle. Requies getting at the ECU and sticking a meter up the back of each plug. Takes about 30-45 minutes.

 

your TPS can read fine and still need to be replaced

 

heh, well since I can't get it to idle without throttle manipulation I guess I'll check the injectors.

 

Rewire all the grounds plus add extra ones.. It does not matter if your engine is new I blew mine right after the first 2000 miles the first time. If the apex seal is gone at the tip (one of the ends) it will sound like a really fucked up V6. Stucked corner seals also can cause a weird idle, check your fuel pressure, I assume you got an aftermarket regulator for that walbro right? Blow compressed air backwards thru the injectors this should take whatever migh be causing them to be stuck (if they are). Spark plug wires and bad coils can also cause this problem.

 

Sorry to bring this back from the dead but I figured it might help someone.

I got a good look at the injectors and one of the connectors was broken to bits and the wires were not making a good connection. Reconnected everything and it ran like a charm