My parents have a 94 Bonneville that occasionally shuts off on them while driving it. It's not the fuel pump, computer, or crank sensor??? The dealership doesn't even know what the problem is. Sometimes after it dies it will start right back up, sometimes they have to wait awhile, and sometimes it won't start back up. Anybody out there have any ideas?

Thanks!

are you sure it isnt one of the two crank sensors? one on the back side of the block and one behind the crank?

I also have a 94 Bonnie and have had the same problem. The first time - about 6 years ago the problem was solved with new battery cables. Recently, over the last 6 months, the car has just gone dead while driving down the road - nothing electrical works or power steering etc...completely dead. When I brake to a stop, turn off ignition and then turn ignition back on, it will crank and start. ...keeping my fingers crossed. I have heard before that there is a major battery cable under the drivers side door step rail or carpet (sorry I can't remember more specifically). Anyway I found the cable a couple of months ago and noticed that the cable and surrounding area was wet/moist. I suspected this was causing corrosion and thought that this explained the intermittent nature of the problem. I need to check and inspect mine again. Maybe one of these areas will fix your problem.

Sounds like a crank sensor to me. Is your service engine light on? If not when you get it fired up run it to an autozone and ask them to scan it.

Good luck,
Sellncars

I have a 95 Bonneville SE 6 cylinder that is doing the same thing. I can't figure out any pattern. Sometimes it dies just after starting but it will also die at 70 mph with the cruise set. It dies with the engine hot or cold and sometimes it dies several times a day but will also go for days without dying. I've taken it to my mechanic and left it for over a month on one occasion. So far they have replaced the timing chain and all related parts (sprockets, dampner, magnet, harmonic balancer, gaskets, crank sensor, etc), the alternator and battery cables. It still dies. It checks out fine on their computer. To make it even more mysterious, it seems that after the mechanic does the work, it doesn't die as often for the first couple of weeks but as time passes it gets continually worse. Also occasionally it is hard to start. I have to crank it and crank it and it will finally start and usually after that it dies several times while driving it. It started about a year ago after I had a new transmission installed (not sure if that's related at all). Any ideas? I'm at the end of my rope (and quickly running out of money and patience). Thanks

On my '98, I had problems like this - the fix was a recall-replacement of the Fuel Pressure Regulator.

YMMV

It's the battery cables. Either they're corroded or worn out. I have a 94 Olds 88, which is the same thing with a different body, and a few months back I had that problem. One sign that tells you that this is the problem is if the vehicle shuts off and won't restart, but the rest of the electronics work such as lights, radio, etc. The reason for this is because there is two positive leads from the battery. One goes to the starter and the other goes to the rest of the electronics. My cables were corroded which caused my car to shut off and restart sometimes, then one night it just shut off. Different conditions can cause the car to do different things such as position of the battery cables and weather/humidity conditions. I cleaned them off with some battery terminal cleaner and protector and it worked just fine. I'd suggest just cleaning the cables off and checking it then.

Thank you for your responses. Unfortunately, in my case these suggestions dont' apply. My mechanic has replaced both battery cables and also the crank sensor. We are going to try the fuel pressure regulator since it is an inexpensive repair and see if that does it. I'll keep you posted. Meanwhile, keep the suggestions coming. It's still stalling

My 94 bonneville does the same thing, got a DTC code of p1406, which is the EGR valve pintle postion error. When I restart the car up the check engine light goes away.

We had a 94 bonnie before our 97 and had these same problems. Dying at anytime. It could be idling, going down the hwy. It would aways start back up and usually be fine. Sometimes it was also hard to start. I replaced everything that I could think of. Usually no light ever came on. We put fuel pump...crank sensors, cam sensors...I can't even remember. Well over $1.,000 trying to fix it and you will not even believe what it was. I fixed it myself with a fuel pump relay that cost me less than $5. It plugs in under the dash along the foot well of the passenger side of the car. After thinking about it...it did make sense all of the trouble we were having. I was ready to trade it off for sure. Someone on this site suggested this to me several years ago. It worked and I was amazed. Hey what's $5 to give it try. I did!
Hope this helps.
Rob