89 Comanche 4.0, Crank No Start

[Ωhm]

I have to ask. 0.7vdc or 0.7vac? CPS voltage, during CRANK, is taken on the AC scale.

[Ωhm]

38 minutes ago, CognizantPotato said:

but I kept getting infinite resistance between A and B.

I would not expect a OPEN circuit between A and B. It is just one wire in/out wrapped around a magnet.

[CognizantPotato]

12 minutes ago, Ωhm said:

I have to ask. 0.7vdc or 0.7vac? CPS voltage, during CRANK, is taken on the AC scale.

I feel like an idiot now lol. Yep I was measuring DC. I’ll have to go out tomorrow and test that again.

[CognizantPotato]

16 minutes ago, JustEmptyEveryPocket said:

You have put a pressure gauge on it and verified at least ~30psi?

 

I would also spend some time and load test your grounds. Both engine to ground and frame to ground. Missing or high resistance can cause all kinds of issues.

 

Have you taken a look at cruiser54's tips for the Renix? If not, you really need to. Complete 1-5 right away.

I’ll make sure to have completed steps 1-5 this weekend. I’ll also try and get a pressure gauge to verify the fuel is okay.

 

Thanks for your suggestions!

[CognizantPotato]

Update:

 

Today I’ve been cleaning grounds and connectors.

 

I did test the CPS again using AC on the voltmeter and only got 0.3V

[JustEmptyEveryPocket]

1 hour ago, CognizantPotato said:

only got 0.3V

That is suspiciously low. I would try another CPS. There had been some OEM units not that long ago. Might try and ask @eaglescout526 to see if he can help find em again. Ohm is the man for electrical questions and eaglescout is the go to for ANYTHING parts related.

[eaglescout526]

60 OEM CPS left.

[CognizantPotato]

43 minutes ago, eaglescout526 said:

60 OEM CPS left.

Are you selling them?

 

If so how much are they?

[eaglescout526]

What I do is members usually contact me, ask me if a part is available and if yes, what I do is give them a estimated price of what it will cost me to purchase(depending on where I get the part from) and either you have me get the part or you don't. Right now I can order some CPS's from vintage and they will cost me around $50.

 

Let me know.

[CognizantPotato]

Update:

 

I have a new CPS in that’s reading correctly. It should be working, but still no spark.

 

 All grounds that I know of are good.

 

I’m getting 12V to ICM and 10.5V while

cranking.

 

All test on the coil seem to indicate that it’s good.

 

Any thoughts now?

[JMO413]

1 minute ago, CognizantPotato said:

Update:

 

I have a new CPS in that’s reading correctly. It should be working, but still no spark.

 

 All grounds that I know of are good.

 

I’m getting 12V to ICM and 10.5V while

cranking.

 

All test on the coil seem to indicate that it’s good.

 

Any thoughts now?

While you were testing the coil did you clean all the connectors? Both to the ICM and coil itself.

[CognizantPotato]

18 minutes ago, JMO413 said:

While you were testing the coil did you clean all the connectors? Both to the ICM and coil itself.

Yep. Everything looks clean. Just to make sure I sprayed it with some electronic cleaner

[JimB]

In stead of checking for spark from a plug wire to ground, have you tried coil wire to ground? I have had rotor buttons go bad.

[CognizantPotato]

58 minutes ago, JimB said:

In stead of checking for spark from a plug wire to ground, have you tried coil wire to ground? I have had rotor buttons go bad.

I have checked directly from the coil.

 

I have a few ideas that I'm going to test out tomorrow. I'll update if anything new is found!

[CognizantPotato]

Update: I took the truck to my mechanic a while back because I started back to college and didn’t have time for it.
 

There was one wire in the harness from the ICM to the computer that was naked and sparking. It burned up the computer and some other components.

 

The mechanic fixed it and it came back home today working great! Thanks all for the help!

[JustEmptyEveryPocket]

4 hours ago, CognizantPotato said:

mechanic fixed it

Keep that person's phone number. If a mechanic:

1. is willing to work on older vehicles
2. can trace wiring
3. doesn't fire the parts cannon
4. can fix what he finds without replacing "everything"

then that person is worth their weight in gold. Of course that is sometimes what they charge for as the labor rate....

 

Glad the truck is working again!