won't accelerate

[DenDSM1983]

i have a 1990 talon tsi that i got from a friend and it came in pieces. i slowly started to put it back together. everything is stock except the turbo (16g). i put in a new fuel filter, spark plugs, wires. i did a boost leak test an found a small leak (fixed). the ecu had leaking caps. i am borrowing one from a friend. the pins in the ecu wiring harness seemed to be switched to a 1991 (pin 6 and 14). fresh fuel in the tank. i set base timing and then set timing at 5 deg advanced. timing has not jumped. the car is running rich and won't accelerate. whenever i hit the throttle it falls on its face. i did a load test on the battery and it seems to be weak. all my grounds are hooked up. i hooked up the snap-on computer and the code that was stored was mass air flow problems. when i looked at the data display the maf shows no flow readings. starting to get frustrated!!!!!

 

[Absit]

Well, if the MAF is showing no reading that would explain your complete lack of acceleration, don't you think? Have you considered replacing it?

 

[DenDSM1983]

i tried another maf. one of my friends was there with his car and we pulled his and it still had the same problems. will coolant sensors, o2 sensor, cas be causing this problem?

 

[1AWD90]

Yes, a bad coolant sensor will cause you to run rich once the car warms up. However, how are you sure your running rich? Did you check your plugs, black smoke out the exhaust, wideband? Also, does it only do it when you try and drive it or also when your in neutral? I don't believe that a bad coolant sensor would cause you to run that rich that you can not accelerate. Do you know what injectors are in the car, stock, aftermarket?

 

[motormilitia]

Did the new MAS you tried have no readings as well or just cause the same problem while driving?

 

[DenDSM1983]

i am a performance diesel mechanic. i have worked on alot of automotive but mostly american. i have never worked on an engine so sensitive. i can smell how rich the exhaust is. the plugs come out wet. no black smoke and no wideband. i cant even get the car to drive out of my shop. its in neutral. anytime the throttle body opens rpm raise a little and then it falls on its face. sometimes when the engine idles high i get knock. it sounds like a rod knock. i went through the entire engine a month ago. from what i was told they are new stock injectors.

i had the same readings with the new maf.

i'll try new coolant sensors.

 

[1AWD90]

Before you do that I have one more thing for you to check. Do you know if your still running the 1990 coil pack and power transistor. The 90's coil pack connectors use 4 wires and the transistors use 6. The 91'-94' coils use 3 wires and the transistor i believe 8. If you are not running the 91-94 coil and power transistor I believe that would be causing your problem.

Also, I forgot to mention if the pin 6 and 14 have not been switched so they would be how they came from the factory in '90. Pin 6 would be green/white and pin 14 would be green. I think that may also have something to do with it because if I remember pin 14 has something to do with the MAF. There is a ecu pinout on here somewhere I just can't seem to find it for you at this very second.

 

[Chaosweaver]

MAF could be shot, the next thing I can think of is the ICM (transistor) or the coils. If you're getting fuel then the spark might not be enough, or the MAF isn't working properly and the ECU doesn't know what to do when you open the throttle so it floods the cylinders.

 

[DenDSM1983]

after 2 weeks of pain and almost giving up, its fixed. if you ever get a car pulled apart go through it and make sure everything is right. dont assume it is. come to find out the ecu it came with was a 91-94, it fried my transistor. they tried to convert the ecu harness to a 91-94. switched all ecu pins around. it was a mess ohm testing the wires. so thanks for all of your input, it put alot of ideas in my head on what to test.