Cold start real rough, Explorer 97


When I first start my 97 Ford Explorer it idles real rough. Like Auto choke stuck,yet fuel injection. I replaced plugs, cleaned injectors and could it be ignition wires?

I grag all ignition wires and am not shocked so I feel they may be good still cause I am not shocked from some short.

The rough idle evens out after couple minutes then good.

Any Ideas?


Several possible causes IMHO.
One could be a sticking Idle Air Control valve. Cleaning them may help and it’s easy to do.

Two could be a weak fuel pump or one that has a faulty check valve in it. Pumps have a spring loaded ball that sits on a seat when the engine is off. This allows the system to maintain some residual fuel pressure. If it’s leaking back then the rough running could be the air being bled out of the lines when started.
Try turning the key ON for a few seconds and then back off. Do this half a dozen or so times. Try starting it. If it starts right up and runs fine then you know that’s the problem.

Another possibility is a leaking fuel pressure regulator, but I would be leaning towards one of the first two. Probably number 2 unfortunately.
Hope some of that helps.