Engine failure but electrial remains

[jerrymacdaddy]

My issue is that my 99 Bonneville will be running fine and then without warning the engine shuts off. I've been traveling down the interstate, stopped at lights, it's totally random when it happens. The radio, lights, and all electrical remains on its just the engine that shuts off. I usually have to give it a couple of turns with the key and it will come back on. I've also had instances where I've had touble starting the car. It turns over but it's like it is not getting gas. Any ideas?

[J Wikoff]

Are you getting a check or service engine light? Get it scanned for codes.

Some possibilities come to mind.

Crankshaft position sensor
Fuel pump
Poor fuse block connections
Ignition control module

[jerrymacdaddy]

No check engine lights coming on. I had a mechanic scan for codes and he said he got one that he reset. He didn't think that was the issue. When he had it out running on a test drive it did not act up for him.

[sonoma_zr2]

my personal experience with this same thing was a bad fuel pump. check your ground busses, maybe you are loosing power to the fuel pump.

viewtopic.php?f=19&t=18515&p=197020&hil ... us#p197020

[jerrymacdaddy]

I'll do that. Thanks for the advise. It's nerve racking driving the car never knowing when it will decide to shut down.

[ChilinMichael]

To chime in here on an easy thing to check, I've had this happen with bad battery terminals (i.e. corrosion). Yes, the car will seemingly stay on but engine will die. Make sure the positive side especially is clean.

[jerrymacdaddy]

I'll check that out also. Thanks

[willwren]

Cut the insulation back a bit on the battery cables. The corrosion hides in there and may not be visible from the outside. This is a COMMON cause of this problem with our cars.

[ChilinMichael]

Tell me about it, I just ordered the last parts to replace the wires going starter -> batt, Alt -> Batt, Maxifuse -> batt with 1/0 gauge.
Corrosion sucks, so yes, be sure to check this.

[dbeast420]

I just dealt with this same problem with mine. It's probably 99% of what the problem is...

[Cadcruiser]

Hi all. I am new to the club and came across this post while looking around the various forums. I experienced this same issue with my 96 Bonneville (that I purchase new) years ago. I would be driving down the road and the engine would just stop, but all of the electrical system stayed on. The engine would crank, but not fire. It got so bad that I was wishing for something bad to happen to the car (like maybe going for a swim in the nearest lake!). Lol. I had to have it towed four times to the dealer. By the time that they would get the car in the shop, it would start right up. Never set any codes in the computer. The dealer also had me drive around with a recording device plugged into the OBD port. It never recorded any issues. The fourth time being towed in was the charm. Initially they couldn't get the car to start, but while they ere trying to diagnos it, it started. They finally got on the horn with the GM tech center. They told them that the only thing that they could think that may cause the issue was the crankshaft position sensor. They told them to tap the sensor with a wrench. As soon as they did, the engine died! Problem solved. I found it very odd that a faulty sensor wouldn't set any type of code, but I guess that is just how it was designed. If I understood it right, the crankshaft position sensor is where the signal comes from for controlling the ignition coils. When the signal stops, the coils won't function. It's like you have turned off the ignition switch. Have never experienced this problem again, but I definitely won't forget it. These sensors are relatively inexpensive (or at least they used to be). Hope this helps.

Todd

[ChilinMichael]

Could very well be. What I've been noticing with my car is that the RPM's drop very low sometimes, my transmission isn't downshifting in time during deceleration seemingly and allowing the car to stall out. That tach can be useful in showing you what's going on, keep an eye on that as well for those having a random stall issue.

[jerrymacdaddy]

Update and new problem: I cleaned up the fuse connections by the driver's side door (under the carpet) and also cut back the insulation on the battery terminal and cleaned it up. This appears to have cleared up all of my stalling problems; however, just recently I'm getting a "security" light issue. Again this is random. When I try to start the car the security light will come on and the car will not turn over. If I wait it out for 2-3 minutes, the light goes out and the car turns over. Any ideas?