1G Possible ecu issue 1g dsm

[Happys_TSI]

1990 talon tsi. Had just got the ecu fixed by ecmtuning. Car ran great for a good couple months, now I’m having a no start issue. I had just done a 2g trans swap, after that is when It started happening. I start the car it runs for 2 seconds then shuts off. I tested the cas by spinning the wheel and my injectors fires and fp turned on, Like they should. But the injectors stopped firing after like 3 turns of the wheel. So I swap it with a known working one, Same thing happens. Is there something I’m missing that’ll stop the injectors from firing, besides the drivers in the ecu?

 

[1990TSIAWDTALON]

Check the coolant temp switch on the thermostat housing. Make sure all wires are good and that they are connected so that we know it isn't that.

 

[Happys_TSI]

Check the coolant temp switch on the thermostat housing. Make sure all wires are good and that they are connected so that we know it isn't that.

I’ll check on it later when I get off work. But also I forgot to mention this in the last post. after it starts and dies, if I go to restart it the fp primes on and off inconsistently, mpi relay clicks when fp turns on and off, and my tach jumps around while the fp is priming on and off. I also found that my iac is dead, because it’s making all sorts of noise so I unplugged it for now.

 

[1990TSIAWDTALON]

Sounds like the ECU needs gone thru by the guys at ECMLink.

 

[Happys_TSI]

Sounds like the ECU needs gone thru by the guys at ECMLink.

They just did but looks like I’m gonna send it out again

 

[1990TSIAWDTALON]

Could you swap out another ECU before doing that?

 

[Happys_TSI]

I have 2 other ecu’s but they’re basically destroyed and they don’t start the car, The caps are fried. Will a fwd ecu at least start an awd or is there a difference? I know someone with a 90 laser.

 

[1990TSIAWDTALON]

Yes it will as long as your car is a 90. They are the bastard, odd cars (and I have 6 of them).

 

[Happys_TSI]

Yes it will as long as your car is a 90. They are the bastard, odd cars (and I have 6 of them).

So I found out last night that the mpi relay was acting all hectic because I had a non oem cas on it. So every time I’d turn the key after the first initial prime, it would click on and off. I put the original working cas on it and the mpi relay issue stopped. But the car still doesn’t run for more than 3 seconds. I have 11.55v at all injectors. Just not staying grounded. Could that cas have killed the ecu

 

[1990TSIAWDTALON]

I wish I had an answer. Maybe someone else will chime in with their experiences.

 

[Happys_TSI]

Okay I’ll leave the oe cas in it and just try the ecu. And hopefully get an answer to my issues that way, thank you for the help.

 

[Happys_TSI]

Ecu sensor ground was burnt up. I’m assuming the cause was the cas. It was an aftermarket part form cardone, it was causing the mpi relay to turn the fp on and off randomly, while ignition was on run not started. Changed cas, now mpi relay issue went away. I’m gonna check some other wire issues to rule it out but I’m pretty sure the cas is the culprit.