Hi, I was having problems with injector ground specific in injector 3, after check for continuity and T-stat ground cleaning, now its working fine. I'm a little worry if the ground was the culprit or tweaking the harness fix it. The T-stat can cause this failure? Because if not the harness is failing.

Thanks

 

It's my understanding that the T-Stat ground (G101) is the main ground for the ECU. No ECU, no injectors, no spark, no nada.

 

Thanks, I wanted to be sure, i don't want this to happen at WOT and blow my engine.

 

It would be odd that an improper ground at the thermostat would only result in issues with the #3 fuel injector. It is much more likely that there is a problem with the ground wire for the #3 fuel injector or a potential intermittent failure of the injector driver itself inside the ECU.

 

Correct. Probably a corroded ground wire leading to the junction box under the intake manifold.

 

Good point, I was on the path of no injectors, not just one injector failing.

Thanks guys for pointing Carlos in the right direction.

 

Thanks a lot, Now I'm going to drive a wire from the ECU plug to the injector ground for testing and twist and move the harness. If this don't work, is there a way to test the ECU driver?

 

A noid light or 12V LED type test light can be used to test the ECUs injector output leads.

The Thermostat ground(s) are for the ECU and the PGM-FI Main Relay, [injector relays coil ground] it would effect power to all the injectors and power to IGP 1 and 2 to the ECU and some engine sensors and valve. /solenoids.

I agree this sounds like a problem with the ECU or wiring/connections between ECU and the bad injector. 94

 

The injectors are ground side switched. They all have a common hot wire (yel/blk) running to them and the negative (switched) side of each injector 1 - 4 goes straight to the ecu at pins A1, A3, A5 and A2, respectively. The 12V hot comes up from one of the power distribution blocks under the intake manifold.