Did fuel injector cleaner cause problem?

[tccrab]

Lawdawg:

This is encouraging news.
It would appear that you're getting spark and fuel to each cylinder. This would infer that the fuel injectors are at least partially working.
The amount of fuel and spark are critical.
The variance in the spark could be indicitive of potential coil problems, but remember, spark plug wires have internal resistance so the shorter the wire the less voltage drop, thus the greater the spark.
Your LT5 uses "Waste Spark" ignition system where two cylinders are sparked by one coil.
Use your volt meter and measure the coil pairs from spark plug end to spark plug end, the pairs are:
1/6
2/3
4/7
5/8
They should measure around 20k ohms. What you are looking for are large differences. Obviously the shorter spark plug wires will have less resistance, so expect a variance, but not a lot.
If a coil pack is failing, it will be fairly obvious.

Good luck!

TomC
'90ZR1 #792