Engine Quits Intermittently

[gulflyer]

I am having an issue with my '07 XLR-V where the engine will just quit suddenly. I pull over, put the car in park and it starts right back up as if nothing happened. This has happened numerous times, everything else seems to be normal except for the fact the engine will just quit intermittently. Has anyone heard of this issue before? Maybe a bad engine control module? Any ideas would be greatly appreciated. Thanks in advance.

 

[ghawk]

Does it ever set any codes when this happens? What about lights and accessories - do they act like the power is shutting off as well? Is there any pattern like speed, temperature, road conditions etc?

If you can be a bit more specific, maybe we can all generate some ideas for you. Way back in the day, I worked for Cadillac and we had some intermittent shut-offs that were caused by a bad ground to the ECU, but they almost always set multiple codes (check engine light on) when that happened.

Gary

 

[gulflyer]

The engine shuts down but everything else appears normal, instrument read outs, lights, radio is still on, etc. It appears to be only the engine that's affected - shutting down. Speed has been as low as just a few miles an hour (backing out of the driveway), to 40 -45 mph cruising down the street. It's happened with the engine cold and fully warmed up as well. No check engine light, but I am going to run a code check on it today.

 

[ghawk]

The good news is that there are only two possible problems - fuel or electrical...The bad news is there are multiple possible issues with each and they are all a PITA. I would start with eliminating one, and the easiest is to eliminate the fuel possibility. Again, way back in the day, we would have the techs get a fuel pressure gauge with a long enough extension to reach the windshield, tape it down so it can be read from the inside of the car and then drive it until it happens again to see if the pressure drops to zero when it stalls. If the pressure remains, it is time to check all the grounds...and I mean all of them...and then try to repeat the issue again. If the pressure drops, it was usually time for a fuel pump and check connections at the tank.

Sorry Its not very specific advice, but until we can start eliminating possibilities its a guessing game.

Gary

 

[gulflyer]

I just checked for codes and there are none. The car runs perfectly normal, doesn't cut out, run rough or give any indication that anything is amiss. It just quits very suddenly like someone hit the 'off' switch. Yes, checking all the grounds sounds like the place to start.

 

[long Tall Sally]

check your battery cables

 

[gulflyer]

Yep, I checked the battery cables first. Good and tight and clean. No sign of oxidation or fowling.

 

[long Tall Sally]

good. I have seen cables that look clean but actually did not make good contact within the post to cable. You have got to have an electrical connection failure I believe to do what you are experiencing . Other wise I think you would see codes. Do you have a tech 2 to check deep codes?

 

[gulflyer]

I agree, I think it's an electrical issue. No, I don't have a tech 2. I did check the fuse box under the hood and found a number of fuses and relays that did not seem to be completely seated, I felt some give when I pushed down firmly. Since then I have had the car out for a few 20 and 30 minute drives with no issues. Of course I still don't know if that really fixed the problem.

 

[n2deep]

I had the same problem a few years back look at an article I wrote for the fix. Few have had the same problem we traced it to a ground on fuel pump

 

[gulflyer]

I had the same problem a few years back look at an article I wrote for the fix. Few have had the same problem we traced it to a ground on fuel pump

I'm interested in your fix - do you have a link to your article?

 

[n2deep]

Search posts by n2deep or xlr shuts off while driving

 

[gulflyer]

Search posts by n2deep or xlr shuts off while driving[/QUOTE
I got your message and read your post. Thanks - that's good information. One thing that's different in my situation though is that after each engine shutdown and I pull over and shift to park, the car starts normally with no hesitation at all or indication of any problem. Since my last post I had the problem again. This time after I drove home, I disconnected the battery for about an hour and then reconnected it, the idea being to 'reboot' the engine control module or any other processors that could be at fault. Honestly, I don't know if this would have any real effect or not, but the car has been fine since. I'm out of town right now and away from the car, but when I do get back plan on doing some serious driving and see if the problem comes back.

 

[n2deep]

I think they all come down to bad grounds

 

[IAN]

Search posts by n2deep or xlr shuts off while driving[/QUOTE
I got your message and read your post. Thanks - that's good information. One thing that's different in my situation though is that after each engine shutdown and I pull over and shift to park, the car starts normally with no hesitation at all or indication of any problem. Since my last post I had the problem again. This time after I drove home, I disconnected the battery for about an hour and then reconnected it, the idea being to 'reboot' the engine control module or any other processors that could be at fault. Honestly, I don't know if this would have any real effect or not, but the car has been fine since. I'm out of town right now and away from the car, but when I do get back plan on doing some serious driving and see if the problem comes back.[/QUOT

HI


Check the battery ground cable, the tiny one is hold by a nut on the frame rail just below the battery, then there is the large one that go toward the firewall area and it is bolt on the frame structure, the battery will have to be remove for easier space to do that work.

A battery charger low amps could be of some help to maintain the current and avoid to re initiate the doors windows, make sure that one of the ground cable is connected for this, with the battery upper connection that are covered, in order avoid contact with the positive and negative connections

The engine ground is just beside the battery in the rear of the RH cylinder head, the ground is a wires strap of about 6 inches, bolting on the engine and the head ( you might have a surprise right there .)

Clean all parts with baking soda with an old tooth brush and a steel brush or sand paper and make sure that all parts are dry before the installation.

Also the ground 201 on the driver side door A post could create some problems as the modules for the engine and the gearbox are related with the engine harness.

That is a very economical way to do it, all you need is only a bit of your arms oil before to go to a CADillac Dealer or else.

Good luck.

IAN

 

[gulflyer]

Thanks Ian, I will look at those areas when I get back with my car. I'm not sure about the driver side door ground and what you were referring to about the 'post' and where that ground is located on the door or door area.

Search posts by n2deep or xlr shuts off while driving[/QUOTE
I got your message and read your post. Thanks - that's good information. One thing that's different in my situation though is that after each engine shutdown and I pull over and shift to park, the car starts normally with no hesitation at all or indication of any problem. Since my last post I had the problem again. This time after I drove home, I disconnected the battery for about an hour and then reconnected it, the idea being to 'reboot' the engine control module or any other processors that could be at fault. Honestly, I don't know if this would have any real effect or not, but the car has been fine since. I'm out of town right now and away from the car, but when I do get back plan on doing some serious driving and see if the problem comes back.[/QUOT

HI


Check the battery ground cable, the tiny one is hold by a nut on the frame rail just below the battery, then there is the large one that go toward the firewall area and it is bolt on the frame structure, the battery will have to be remove for easier space to do that work.

A battery charger low amps could be of some help to maintain the current and avoid to re initiate the doors windows, make sure that one of the ground cable is connected for this, with the battery upper connection that are covered, in order avoid contact with the positive and negative connections

The engine ground is just beside the battery in the rear of the RH cylinder head, the ground is a wires strap of about 6 inches, bolting on the engine and the head ( you might have a surprise right there .)

Clean all parts with baking soda with an old tooth brush and a steel brush or sand paper and make sure that all parts are dry before the installation.

Also the ground 201 on the driver side door A post could create some problems as the modules for the engine and the gearbox are related with the engine harness.

That is a very economical way to do it, all you need is only a bit of your arms oil before to go to a CADillac Dealer or else.

Good luck.

IAN

 

[IAN]

Hi Gulflyer.

''A post'' is the frame structure portion for the hinges door.

The ground block ( pack ) contains many ground wires and it is located in the lower portion of the hinge post.

The post trims have to be remove by pulling them away, they are only press in the door lower frame.


I have made a recently thread about '' Know were the ground are '' take the time to read it.

Enclosed are photos of the ground 104 for the battery and ground 106 for the motor, also were most of the grounds are located.

Hope that it will help.




IAN

 

[long Tall Sally]

Ground wire failure usually will stop a car but I am not sure how its going to start right back up with out the ground being cleaned. When the car stops do you loose all power? lights on the dash, radio headlights at night wipers if on? Or does just the engine stop running?

 

[gulflyer]

Just the engine. I'll be driving, the car running perfectly normally, no sputtering, cutting out, etc. The engine just quits, a "SHIFT TO PARK" message appears in the drivers information screen, and now that I think about it the radio quits. So I pull over, stop, shift to park, and push the 'Start' button. The engine starts immediately.

 

[gulflyer]

Thanks, Ian - very informative. That should definitely help discover a grounding problem

Hi Gulflyer.

''A post'' is the frame structure portion for the hinges door.

The ground block ( pack ) contains many ground wires and it is located in the lower portion of the hinge post.

The post trims have to be remove by pulling them away, they are only press in the door lower frame.


I have made a recently thread about '' Know were the ground are '' take the time to read it.

Enclosed are photos of the ground 104 for the battery and ground 106 for the motor, also were most of the grounds are located.

Hope that it will help.


View attachment 8785View attachment 8786View attachment 8787

IAN