No start 4.0

[jeepboy381]

So I drove to a friends and the Jeep was working fine, I shut it off and went inside for an hour or so. When I came back out I couldn't get it to start, it would turn over just fine but it would not fire up. It's a 1987 4.0. The coil, ICM "ignition control module," plugs, wires, and fuel pump all are in good working order and passed the multimeter test. I am getting no spark though? The fuel pump turns on and I have fuel pressure but it seems like the injectors are not opening and letting fuel in, after cranking the sparkplugs are still dry. Will the fuel pump still run if the CPS is bad?

 

[MJmk]

Had that happen on my '87, but it was a bad connection where the CPS plugs into the fuel injection harness. Wiggled the connector and it would start. Got a kit from the dealer to wire the CPS directly to the ECU and havn't had a problem since (with that anyway!).

 

[serge]

Will the fuel pump still run if the CPS is bad?

Yes. Engine will crank all day, with FP running to keep pressure up, but injectors will not spray fuel since ECU is not getting a signal from CPS. Do a search on how to test Renix CPS operation. It's been covered many times

 

[jeepboy381]

I replaced the CPS last night outside while it was snowing, those have to be the hardest two bolts to get out on my whole jeep!!! It took over two hours and I just gave up on getting the second bolt in. I will install it next time I drop the Tranny or transmission. Well at least it started!! Thanks for the replies!