Engine stops and immediately restarts when driving

[Drew]

Hello to all,

I have searched around the forum looking for possible reasons as to why my vehicle stops and starts right back up while driving. I’ve seen where some vehicles stop then start after a few minutes, but in my case it’s a little different. Here’s what happens…and all in less than a second.

Happens usually on highway @ 70-80 mph
Engine shuts off
all gauges fall to the left
feels like i hit a boulder
engine pops back to life
keep on driving.

Details: 2003 Jeep Grand Cherokee, 163K miles, 4.0L engine NOT 4×4

I’ve recently replaced the sparks and the coil pack, but this problem also happened long before that. it’s been random. I thought it went away but here we are. More recently I’ve repaired a EVAP leak, which led to replacing IAC and TPS (b/c I broke it reaching for the IAC). But again, this same problem has happened before, about a year ago. Pretty sure i have bad motor mounts and need to replace the drag link and ends, but that’s not related…is it?

I’ve thought maybe the timing chain, maybe the battery/alternator, maybe the fuel pump…it’s my wife’s car so maybe it’s Maybelline (sorry, bad joke but not out of realm of possible).

Any suggestions would be helpful. Gotta keep this thing going. Thanks all!

Topic

[Alexander B]

Sounds like an electronic issie, ignition switch?

[Drew]

If it were an electronic issue, wouldn’t I need to restart the vehicle when this happens?

In order to figure that out could I just sit in the car in the driveway and play with the key while idling and see if it cuts off?

Thanks for the suggestion!

[Alexander B]

If its still rolling in gear, it’ll bump-start by itself as soon as electricity is restored. and continue on as if nothing happened.

You can try, sounds like a good way to find out if that triggers the issue. 🙂

[Richard Kirshy]

Just a thought …
Might have a look at your under hood fuse block ( with the fuses and relays removed ) also your power and ground cables for signs of corrosion.

[My Nameis]

Sounds like an electrical issue as others have stated.

Possibly a power wire of some sort in a loom has chaffed causing the insulation to rub off and it could be grounding out at certain vibrations cutting power off momentarily till it works itself free and all is restored.

Run the engine and physically shake any wire harness you can see under the hood, car, inside, etc see if you can replicate it.

Also make sure fuses and relays are secure, try same test with those

[James P Grosso]

Sounds electrical as mentioned. Do as the others posted. I hope you can find it easely, otherwise you might need to tap some wires and monitor/data log the voltages to capture the offending circuit

[Author]

Replies