My rear rotor's primary injector will not energize when I rotate the CAS gear with the key ON. It does every once in a while and its random...Front rotor's is nice and consistent every full turn or so. I have tested the coil, resistance checked out good (13.8), I've energized it with the fuel system pressurized and the spray pattern looks normal. I haven't made any wiring modifications to cause this (car went down for 6 port turbo) and I got source voltage (12v/14v) at both idle and with the key ON.

I want to make sure the problem is a driver on the ECU not pulsing the injector but I'd like input from the pros before I buy one. This ECU is new to me and was purchased used here on the classifieds.

 

what model ecu do you have

 

N37x out of an S5 TII. Car is a 90 GXL.

 

humm

 

N374????? What number

 

Yup N374. No wiring modifications were made. If it matters I believe the car was an automatic before.

 

If you do a Search for N374, you'll find a number of other people who have had the same problem as you do. I know not why. Others say they've seen no problem using a N374...............but lots more have your problem. Again, I know not why.

Auto should have no effect imho.

 

im having the same problem with mines.. the exact same thing..

 

Edit: So after searching I've found the problem is the ECU. Amazing, I probably put 20+ hours of troubleshooting into this car and it was the damn ECU. Thanks for the info everyone, close thread.

 

If you have a spare non turbo ECU, it SHOULD start the engine. That should prove it's not wiring.

I've no idea why the N374's don't work for some people and work for others. Mystery.

 

Yeah I sold it for 10 dollars... lol. The N374 has been known to work with the knightsports chip upgrade but I don't think the "upgraded fuel and ignition maps" will be 9.7:1 compression and 6 port friendly...