Need Help with 90 AWD tsi

[6damian6]

I have this annoying problem with my 90 AWD and need any help that I can get to diagnose this problem. Here it goes one day I go to start my car and my check engine light pops up and my car sounds like it was running on 2 pistons so I tried to ignore the problem and started driving home and it was going really slow and then the check engine light goes away and the engine starts running fine. Now this has been happening to me randomly for the past 2 days. Also when my car does run fine and usually when i'm in 2nd gear or 3rd it will start to sputter and backfire throughout the RPM range. Now when I started up my car again today the check engine light came back on and I was again on 2 cylinders and then 2 min. later it went away so I try to drive home still and the car starts running fine untill I get about a block away from my home and I hear a loud backfiring sound and my car starts to feel like it was gonna die. I was on the gas pedal and the engine sounded like it was running on 1 or 2 pistons and no power was going to the wheels. Also the RPMs weren't going higher than 3000-3500 and it took a very long time to reach 3000 RPMs and I could not go over 35 miles per hour! All of the sudden my car gives out 2 loud pop noises from my exhaust and dies. So I pull over and pop my hood and there was this wierd smell coming out of my engine bay like something was burning? and I saw some smoke coming out around the intake manifold side of the engine. Also the engine seemed hotter than usual like it was overheating. I tried to start the car again but it keeps making this wierd sound and you can hear the alternator trying to turn over but the engine won't start. Also when I try to start the engine sometimes i'll get the loud pop noises coming from the exhaust. Everything on this talon is pretty much stock besides running 15 psi on a MBC on the stock 14b, a walbro 255hp fuel pump, BS removed, hacked MAF, K&N filter, and new waterpump and timing belt. Any help that i can get is appreciated thanks

 

[steve]

Why don't you pull the error code and fix what the ECU thinks is the problem to start with.

Steve

 

[gurmanator]

timing or ignition...backfire is a classic sign...check timing,plugs and wires,coil pack.

 

[6damian6]

The check engine light doesn't come up anymore it's just dead

 

[steve]

Have you checked the ECU for the typical capacitor leakage?

Steve

 

[BigG]

The check engine light doesn't come up anymore it's just dead

i have the same problem. car died, then sputtered and popped, then lost the CEL. About 30 hours later the CEL came back, the car started fine, ran for a few minutes, then died. then the whole cycle started over again. the sputtering and popping gets worse until i lose the CEL. I oredered a logger a few days ago. i'll keep you posted with what i find, as well as keep watching your post in case you get fixed first

 

[steve]

The CEL that you get when you first turn the key on is an indication that the ECU has powered up. On turbo cars the boost gauge will also move to the 0 mark if your running standard software.

If this doesn't happen then checking timing, plugs, wires, coil pack is a waiste of time because nothing interesting is going to happen if the ECU isn't running. Instead you shoulc be checking the MPI and ignition fuses, pulling the ECU and looking for capacitor leakage. Checking to see if the ECU turns the MPI relay on.

Steve

Steve

 

[6damian6]

Actually the ECU has been rebuilt recently by the previous owner before i brought the car stock so i'm doubting it's the capacitators leaking. the car tries to turn over but no magic happens and sometimes it won't do anything when i try to turn the key....really frustrating. the spark plug wires have also been recently changed and the spark plugs look like they're in decent shape so i don't think they're the problem. i also did a timing belt change a couple of weeks ago and i'm positive i did the timing right when i did the procedure. so that leaves me to go to the junkyard today to get a coil pack and see if that changes anything. oh and also when i do try to start the car the CEL does pop up in the beginning like usual start ups but then goes away so i don't know if one of the sensors is faulty or a part is bad. once i swap out the coil pack i will post any changes

 

[steve]

Please don't assume parts are good without testing them yourself.
That includes anything you pick up from the junk yard as well as anything somebody before you replaced.

You want to start by checking the high probilibity items first and working down the list. Since you said that the CEL before that the CEL no longer came on at all that would put the ECU and it's power sources on the top of the list. Coils are actually pretty low since they are generally reliable. The CAS, Power Transistor Module, or the connectors are more likely to be bad than the whole coil pack

The normal procedure on power up is for the CEL to go on for 5 seconds and then turn off unless you have active errors. The boost gauge will go to zero and stay until you start cranking the car.

If the car doen't crank (sometime or all the time) when you turn the key you have another problem not directly related to the car not firing when it does crank.

Steve

 

[laserspeeddemon]

A month ago, I had a problem similar to this. After bouncing the rev limiter in 1st gear twice in a row (was high rpm boost). The car was sputtering and sounded like it was a Subarau, I pulled the code with a data logger a friend had. It was fuel injector circuit failure (or something to that tune). I pressed down hard on all the fuel injector and the car returned to normal.


Yesterday, I had the same problem, the car was sputter and weak. I could not get it to rev pat 4000 RPMS. This was shortly after I washed the car to include the engine bay. I plugged the spark plug wells with rags, but water still got in. I used the top from a spray bottle and stuck the hose down there and pumped it dry. Then I sprayed the spark plug well with WD-40. I let the car run for a while and the problem disappeared.

Lack of spark and fuel caused similar symptoms.

 

[6damian6]

A month ago, I had a problem similar to this. After bouncing the rev limiter in 1st gear twice in a row (was high rpm boost). The car was sputtering and sounded like it was a Subarau, I pulled the code with a data logger a friend had. It was fuel injector circuit failure (or something to that tune). I pressed down hard on all the fuel injector and the car returned to normal.


Yesterday, I had the same problem, the car was sputter and weak. I could not get it to rev pat 4000 RPMS. This was shortly after I washed the car to include the engine bay. I plugged the spark plug wells with rags, but water still got in. I used the top from a spray bottle and stuck the hose down there and pumped it dry. Then I sprayed the spark plug well with WD-40. I let the car run for a while and the problem disappeared.

Lack of spark and fuel caused similar symptoms.

Yes does sound very SIMILAR! especially about how my car also sounded like a subaru also! will go test out my injectors now thanks any other suggestions?

 

[ICGerms]

...will go test out my injectors now thanks any other suggestions?

Yeah, put a datalogger on it to see if the code from the CEL has been stored in the ECU. They don't always disappear when the CEL goes off.