Ok I have been getting detonation in # 1 cylinder and bad misfire under boost for a while now and it closes the gap on the spark plug. When it does this it runs like crap for about a minute then it will come out of it if the gap is not closed on number 1 spark plug. I have swapped out everything possible sencor wise and ignition wise. injectors ext. Has all fuel supporting mods as well as new eprom ecu. Only running lowest possible boost at 9 psi. I have determined this to be in the wire harness. The car idles great and runs great under cruise conditions. Under boost is another story. What voltage should I be getting at the injector clips?

Here is what I have done so far:

key off out of car.

batt voltage is 12.4 volts

black lead on batt + red lead on injector + = 15.87 ohms

black lead on batt - red lead on injector - = 80 ohms

resistor pack unplugged black lead on batt - red lead on injector+ = 0L

resistor pack unplugged black lead on batt - red lead on injector - = 80 ohms

ECU unplugged injector resistor pack unplugged:

black lead on batt - red lead on injector - = 0L

black lead on batt + red lead on injector + = 0L

Ok everything plugged back in key on engine off

black lead batt - red lead on injector - =2.27 volts

black lead on batt - red lead on injector + = 11.94 volts

black lead on injector - red lead on injector + = 7.0 volts

black lead on batt + red lead on injector + = 1.89 ohms

The voltage seems to be the same on all injectors. Am I missing something here? number 1 injector is having the problem.

The injector resistor pack tested good at 6 ohms and I swapped one just to make sure and no change.

Just plugged in a spare 90 auto ecu and the same readings exept getting .322 ohms instead of 80 ohms on my eprom with the black lead on batt - red lead on injector - = .322 ohms Is it possible to have a bad injector driver that ECM tuning missed or does it sound like a short to ground? Any help is greatly apriciated!

Anybody?

Nobody knows anything about this?

It was the injector wires that had the short. I rewired the injector and all is well. Only took about a year to trouble shoot it. I havn't heard of a lot of people having this problem so not much info out there.

Where in the injector wiring was the short? Did you find it or just give up and rewire them and presto it was gone?

It was most likely in the injector wire pig tail first 6" from plug. It was however really hard to diagnose because it ran fine exept under wot. It was hard and britol. I just put on a new injector wire plug and rewired + to the injector resistor pack pin 1 and ran a new ground wire to pin 51 in the ecu and no more cut out or closing spark plug gap. Going to replace the other 3 clips even though they aren't shorting because they are hard and britol and two of the clips are broke. The new clips are much easier to get out then the retaining pins like stock and fit tight. I got them at napa.