Rough Idling and Stalling
I have a 1991 Ford Ranger with EFI 4.0 V-6. It idles really rough on cold starts, and it seems to idle even worse if the outside temp is cold. Also, when you put it in gear (automatic) it sometimes stalls out. If it stalls, I can't restart it without pumping the gas while turning the key. It idles a lot better and doesn't stall when it's warmed up fully, but it does sometimes hesitate.
I already changed all the plugs, plug wires, PCV valve, fuel filter, IAC valve, TPS sensor, checked the Air charge sensor, checked the ECT sensor, and I cleaned the MAF sensor. Nothing seemed to help.
Anybody got any ideas?
I pulled the codes and the only one I'm getting is the HEGO is not switching, but I don't think that would cause all my symptoms and it's usually not the oxygen sensor anyway that throws that code