91 Comanche starting problems

[Comanche777]

Help

 

I have a 91 Comanche Eliminator that has been having various starting problems. Sometimes, cold it will crank and not start until you turn the key off then on for a bit, but starts fine warm. Other times it will start fine cold but require the key off and on ritual to start warm. Last night I went to the store, did the cold start routine, drove to the store and when I came out I turned the key and nothing. Had to push start it to get home. Checked the battery, got 12.9v. Disconnected the negative terminal for a bit and when I hooked it back up the truck started right up. All I can think of is the ECM. I was eying the fuel pump or the fuel pressure regulator but after last night, I am thinking the computer is going out.

 

Any ideas?

 

 

Thank you

[Comanche777]

Incase anyone is interested, I replaced the computer and it fixed everything. Starts and runs like a new truck. BTW, if you ever have to do this, DO NOT go by what the AP store says you need. I found that the OEM number on my computer was what the store called out for an automatic trans not my AX15.

[HOrnbrod]

Incase anyone is interested, I replaced the computer and it fixed everything. Starts and runs like a new truck. BTW, if you ever have to do this, DO NOT go by what the AP store says you need. I found that the OEM number on my computer was what the store called out for an automatic trans not my AX15.

 

Sometimes the pins in the 64-pin ECU connector get corroded and/or recessed. Especially on the 91s. Before replacing the ECU, disconnect and inspect for recessed pins, and douche the connector's pins down with a good electrical contact cleaner. I do this about once a year and it seems to help each time.

 

BTW, how much did the new ECU set you back? :eek:

[Comanche777]

Autozone $156

[Comanche777]

Good point on the connector, I checked mine and they looked ok, the factory used some dielectric grease on the connector so I didn't see any corrosion