My 94 Z-28 is not fireing #7,5, and sometimes #3. #2's wire insulation had come apart under the electrical tape. I replaced those wires from the injector plug to the larger wire loom. I bought a new computer and still same problem??? Any suggestions???

Havasurick


Stock LT-1

 

I had same problem. But, I run Low impeadence 72# injectors with an Acceleronics drive box. Injector wiring resistance on power and ground sides is very important. I removed the inj-harness and re-soldered. Tested with a digital VOM. It's critical to measure the speed of "ring" test (not the VOM sound but visual bar display).

The PCM fires inj by completeing the ground circuit (individual 8 wires to the PCM). Stock power supply is from a common 12v+ conductor. I would ring each circuit to the PCM connector.

Quality of the injector solder joint is very important since the inj fires in milliseconds. Resistance is the enemy. The stock wires look like 20ga (I used 16 ga) and when old, can break (multi heat cycles) causing an intermitent open or increased resistance when old (not good).

Just my experience. Best of luck. B.

 

I soldered the wires well and used shrink wrap but the wire I spliced was not the same color of wire its self that I removed. The original was a copper color. The wire I replaced it with was a metal color?? Problem? Same 20ga.
Thanks for the help!

 

Have you Ohm the injectors? shouldnt be more then 15 Ohm
the ground wires should have the least amout of resistance for the ground to trigger the injectors so your solder and replacement wire could be causing the problem. did you use a high lead solder? are they single strand wires 7 ect? Im not an expert but I do know that silver conducts better then lead and solid wires over multi stran. If you find the resistance in the wires that are firing right you could then figure you need to make the other wires the same or less. At least thats what Im getting out of what Mzgp5x is saying.

 

Did you check the plugs for detonation? My '94 was running like **** this summer because most of my plugs had detonated, got 'em replaced and she ran like a champ again until my current fuel/spark issue. I'd say that's worth a look.