Random engine shutoff

So my 2004 EB has been giving me some grief for several months.

Doesn't matter what I'm doing, or whether I'm sitting still or driving at any speed -- the engine will just shut off. Sometimes it sputters first, like it's not getting gas, but usually it just flat-out dies. The ONLY way to get the engine to restart is to turn the key off, take it out, open the door (to turn off radio, etc), close the door, and only THEN can I turn the engine back on. Otherwise, it just sits there and tries to start without success.

This happens maybe once every 2-3 weeks. As you can imagine, it's scary as hell when it happens while driving 60mph+. I lose power steering and have to pull over as quick as I can.

My longtime mechanic had the truck for 3 weeks -- ran the engine at idle most of the day with a diagnostic machine on it, drove it 80+ miles... it never happened to them. I picked it up and went to lunch, it died at the restaurant.

The fuel pump and fuel regulator have both been replaced. Problem persists.
The new fuel pump has been checked over. Problem persists.

It throws no codes nor check engine light, etc.

I recently accepted a job about 10 miles away and 3/4 of the trip is on the highway. I can't trust this truck on the highway, so I have to go on side streets which nearly doubles my travel time. Road trips are out of the question, pretty much.

Hit me with your questions - maybe we can figure this out?? Otherwise I have to sell it. Can't afford to throw more money at it hoping to solve the problem at this point.

I would remove each plug on the computer and check for corrosion. I'd also do the same with the fuse block on the kick panel, checking for evidence of water and leaks. Then I'd switch the fuel pump relay with another. I'd also look at the battery and main ground terminals.

Try juggling the key in the ignition switch and look for some adverse result.

That's where I'd start.

Yes, check the harness there at the computer on the firewall, and check the PCM relay in the upper right corner of the fusebox for any melted plastic around the terminals. If it's the original fusebox, the '03-'04 years had a problem with the fuel pump micro relay on the fusebox circuit board melting. In it's early stages of failure you will get these random shutoffs of the fuel pump, which of course kills the engine, with no codes. Have to replace the fusebox with a new one, or have the fusebox repaired (eBay).

Hamfisted said:

Have to replace the fusebox with a new one, or have the fusebox repaired (eBay).

Click to expand...

Well that certainly doesn't sound fun (or cheap), but this seems to address every issue I've had. Thanks to you and Trainmaster both -- I'll have to get in there and check the relay & fuse box.

Do all the instrument panel instruments, lights, etc... go to zero/off when this issue occurs?

Trainmaster said:

I would remove each plug on the computer and check for corrosion. I'd also do the same with the fuse block on the kick panel, checking for evidence of water and leaks. Then I'd switch the fuel pump relay with another. I'd also look at the battery and main ground terminals.

Try juggling the key in the ignition switch and look for some adverse result.

That's where I'd start.

Click to expand...

GM had massive problems with their ignition switches - and many of the problems were caused by people having numerous things on their key ring, which caused excessive wear on the ignition switch cylinder over time due to excessive weight.

Does the OP carry numerous items on their key ring (or did the prior owners)? When the mechanic tested the vehicle, did they only use the vehicle’s keys and not the “full” key ring which may have more weight?

The concept that the problem lies in the key cylinder causing the shut off, or an issue with the battery and/or its connectors and wiring, is a good one.

I had an issue on my '05 where I needed to replace the fuel control module. It is located near the left rear tire and is prone to corrosion. It is a quick and cheap fix. I did it myself in my driveway. Good luck

FCM came out in 2005 & is not on the 2004 models. Sounds like on board fuel relay as Hamfisted stated. Been thru this myself.

I have a 2003 Expedition. Same thing happened, numerous times. After numerous attempted fixes I found out that the coil over plugs were bad. I figured 1 or 2 were bad but didn’t want to fix those only to have others go bad. I replaced them all. No more problems. Coils are about $70 each.

My money is on the fuel pump relay as stated above. Plenty web info available on fixing/replacing this.