Ok I have a no spark issue. I have spark at the coil but not at the plugs. I figured it was cap and rotor so I replaced both. I still get no spark at the plugs. I tested the plug wires with spark tester by plugging them onto the coil and plug wires are good.
I tested ICM and PIP signals and they are present.
This has me really stumped. What am I missing? Is it possible I got a bad cap and rotor? Its an Accel brand which I thought was pretty good.
What else can I check?


Thanks for any help,
Daniel

 

Sorry would probably help if I told you the vehicle specifics.
Its a 1991 F-150 with 5.8 automatic. Also has the ICM on the distributor.

 

What is the quality of the spark? Is it a lightning bolt-blue spark or a more of a static cling-yellow spark? If it is the latter, your coil may be crapping out. A weak coil will fire a plug out in the open air but with reduced intensity. It will not have enough ump to fire a plug under compression. The hotter the temps the worse it gets.

 

It's a good spark. Coil is new. I have one of those inline spark testers and it lights the light up.

 

And it doesn't spark a single plug after the cap? Did you replace the wires also?

 

No I put spark tester at each plug wire and no spark. Also switched out coil wire with the spark plug wires and used spark tester and it lit up so I know plug wires are good. I'm guessing I have a defective new cap and rotor. I guess I'll take it back and get another one. I'm out of things to try.

 

Yup. That would be the next step. Where is the old cap and rotor? May save you the price of another one in case that's not it.

 

I still have the old one it had a lot of wear anyway so I'll still put a new one on. We'll see what happens with another new replacement.

 

Oh, I agree. But at least you will know what parts to go fetch and another new cap may not fix the problem, and it would just be a wasted trip.

 

Ok I put a cap and rotor from another truck I have that runs and it still wont run. I put the new cap and rotor on the truck that runs and it ran fine.
So I know its not the cap and rotor.
Im getting really frustrated with this and if I cant get it running today its going to the shop tomorrow which I don't want to do but I need this truck running.
So what else can I check? Im at a loss here.

 

Try swapping the coil off the other truck and see what happens. After that, I have no idea.

 

Ok apparently I have spark at the coil enough to light the test light but it doesn't spark a spark plug. I put a spark plug at the end of coil wire and it didn't spark the plug. So I guess its a weak spark at the coil.
What would cause that?

 

New parts don't mean good parts. Your coil is bad. Nothing caused it, the coil just died.