Stumbling and rough starting | Ford Explorer Forums - Serious Explorations

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Stumbling and rough starting


March 25, 2003
Reaction score
City, State
Stratham, NH
Year, Model & Trim Level
2018 Explorer XLT
I have searched and still am not sure the cause of my problem. My X used to start up excellent and after only a few cranks she was running. But ever since about 2 weeks ago it has had a problem starting after it has been sitting a while. The problem is hard to describe but i will try. I turn the key after waiting a few seconds for the fuel pump to do its thing and when i do try to start, it cranks for a while, tries to start, stumbles, and decides it doesn't want to start. If i then turn the key to start immediately after this, it fires up no problem. What is going on with this? It only does it if it has been sitting for longer than about 30-45 minutes. It always happens in the morning or when I go to leave work as it has been sitting for a while. Could this be the ICM? Fuel filter (No idea when it was changed last. It has been at least 30k miles)? Something else?

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Scott, something in the back recesses of my memory says this is related to the ICM. The key is that it starts normally on the second try. I would have the ICM tested, or go ahead and replace it (depending on the cost).

How would I get it tested? Where? I absolutely refuse to go to the dealership. Way to many bad experiences with the dealers near me. Could I go to my local junkyard to get one? Can't be positive it would work though i guess seeing as it has been sitting in a yard. Any one else have any thoughts? Could I cause any damage to my engine or other components if it stays like this for a few more weeks? I just started working and won't get paid until the end of next week so big expenses can't happen yet. Anyone know how much for a new ICM? Thanks for any help you guys can give.

Scott, many auto parts stores will test ignition modules for free; AutoZone is one. There's also a testing procedure in the Haynes manual using a multimeter.

If money's tight, I would get one from a salvage yard. They should exchange it if it turns out to be bad, and the price will be less than half that of a new one. Seems like a new one is in the $100 range.

The trouble with the ICM has to do with the PIP signal, or IDM signal, or something like that. You can't damage anything by driving it, assuming it runs OK, but it may get to where it won't start at all.

Ignition Module
YIKES!!!! :eek: They're $294 new. Be sure and test yours first, to confirm it's bad and that's really the problem.

Another common problem on cold startups is fuel leakdown. If the fuel rail loses pressure fast enough, it can take more than one "turn the key on and let the fuel pump run" cycle to get the pressure in the fuel rail high enough for the engine to start. A quick test with a fuel pressure gauge should tell you if this is your case.

$294!! :( I really hope that is not the problem. I really don't have that kind of scratch lying around.