Did you check the asd relay? Is it turning on? If so then you should have 12+ at the coil and won't have to bypass it. Need to check it because the injectors get 12+ from it to. The pcm sends a negative pulse to fire the injector. The asd relay will turn on(ignition) but not stay on if you don't crank the motor so keep that in mind.

 

I have swaped the asd relay with the horn relay.

I bought the noid light set from harbour freight. Reviews said they were dim and hard to see. I tested on one injector, it blinked very brightly!

The coil: the one wire seems to go up to about a little over 10 volts for about 2 seconds when we turn on the key, then gos off. It blinks with a led test light when turning over the engine. What does the other wire do and how do I test that?

I bought another spark tester from Napa. this one. It won't show a spark at all even when I set it at 20 and it says a HEI ignition should be able to spark at 40. It won't spark at any point in the system, even at the coil wire.

Ive got this test light from harbour freight and it will blink at the coil wire, but not at plug wire.

i have a new coil on it. New cap and rotor. I'm going to put the old cap and rotor back on it in the off chance that one of them is bad, but not hopeful.

​​​​​​​I think I'm having a different problem than what I even started with really. I didn't test the crank or cam sensors because it seems like the injectors and coil are getting a signal, but somehow the coil just isn't firing hot enough.

 

Asd relay supplies 12V+ to one of the coil wires, The other goes to the pcm. It gives it a negative when it's firing the coil. The noid light is flashing then you should be getting power from the asd relay. Set the spark tester to a gap on a spark plug then test it from the coil wire going to the dizzy and see what you get while cranking the engine.

 

So the hot wire to the coil shouldn't blink? I can't even read it with my volt meter while cranking the engine because the voltage gos all over the place and with a led test light it blinks while turning over.

 

So, all your sensors are doing their job. If you aren't getting spark across your tester on the coil wire though, that implies a bad coil. Yep, even new out of the box, they can still be bad.

 

Sounds like he's weak on voltage to the coil and intermittent.

 

Can somebody please verify: is the green wire to the coil supposed to be HOT all the time when cranking and running? Or blinking?
my manual shows in one place to use a test light and says it should blink, but then shows a wiring diagram that shows the green wire going directly to the asd and then the battery.
​​​​​​​Will I be OK to just cut it and splice a wire from the battery directly to the coil green wire for testing? I have today off. Want to get this truck running today. Thanks.

 

Put your test light across the terminals in the coil connector. the light should blink while cranking.

 

I'm talking about with the connector disconnected if I stick my probe in the green wire side it blinks. I read that the other one is the signal wire and operates by grounding. So should I just hook up a hot wire straight off the battery to the green wire?

 

The ASD wire to the coil n fuel pimp should be hot all the time when the ignition is turned on at the steering column and does not blink. It's the signal wire that does the "switching/blinking".