Stalling

Hello all,

the old 88 4.0 has been stalling on occassion sometimes when I am rolling down a bumpy road at low speed say around 20 to 30 mph or if it has been idling and you get in and slam the door hard. I have replaced the CPS and I know that is good but I am wondering if perhaps the fuel pump balist(sp?) resistor is going bad?? Any thoughts would be appreciated.

Thanks,

It sounds to me as if you have a bad connection somewhere which is cutting out with vibration. The ballast resistor might be one suspect, but I'd look also at all the connectors in the engine bay. You can at least unplug and replug every one you can find. This often helps with those mystery problems. A little contact cleaner can help too. Don't forget the notorious "C101" connector on the firewall, too.

My 87 cut out on bumps and rail crossings and it turned out to be a problem with the wiring at the fuel tank.

You should also check grounds. The braided ground strap that goes from the valve cover to the firewall can corrode away without looking that bad.

I once had a bad ballast resistor too... It was cracked all the way through. Normally it was touching all the way across the crack, so no problems. But, during serious vibration (like on a washboarded road) it would intermittently cutout. I figured that the resistor mustve shifted a bit sometimes, opening the circuit.

Just another thing to check...

HTH, Tom

Thanks guys! I will check it all out.