Ok, I'm having a problem with my friends car. It randomly loses power, starts stumbling, then dies. Random, but usually at least several times a week, sometimes several times a day. Always starts right back up within 3 tries.

No CELs.

Cleaned and unclogged the previously mostly plugged EGR port in both the head and the manifold 3 weeks ago.

Fuel pump DOES still work immediately after it shuts off, so I'm thinking its not the main relay.

Electrical systems stay on when car shuts off, so I think that rules out the common ignition switch problem.

It runs perfectly fine 99% of the time, right up until it suddenly stumbles and shuts off.


Is there anything else I can check? Has anyone had a similar problem? I'm a little lost as to how to diagnose this, as its not my car and I haven't been in the car while it happens, but I've asked a lot of questions to try to narrow it down. I did the EGR port cleaning. I did drive it under normal driving circumstances for about 20 minutes and it drove just fine.

 

We're thinking the fuel pump is starting to go, but works most of the time. My little sister's Ford Taurus did something similar, except it didn't cut off while driving, it would just randomly not start sometimes. Fuel pump fixed it.

Does that sound like a good possibility?