Car stalls no matter if going slow or on highway at interstate speeds

2005 BUICK LA CROSSE
90,000 MILES • 3.8L • 6 CYL • 2WD • AUTOMATIC
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RJNAGEL
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The car will stall no matter the speed and will start right back up after putting it into neutral.

We have replaced over the past eight months:
Air filter
Mass Air Flow Sensor
Three ignition coils
Two oxygen sensors
Crank shaft position sensor
Ignition module (under coils)
ECM and had dealer Flash it to the VIN
Mass air pressure senosr
PCV Valve
EGR Valve and EGR Valve Gasket

Fuse 15 (read it online) was fine and tested fuel pump and it tested in working order as well.

(Two dealerships could not find an issue either - throwing no codes) so paid our money and left with no fix.

Any other insight would be great as we are very frustrated.

Thanks!!!
Jun 5, 2019 at 5:02 PM
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ASEMASTER6371
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Good evening,

What was the actual fuel pressure when you checked the fuel pump?

Also, did anyone check the ignition switch? That was common for shutting off.

https://www.2carpros.com/articles/engine-stalls

Roy
Jun 5, 2019 at 5:14 PM
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RJNAGEL
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60 PSI is what the fuel pressure was when testing while running. When revving engine, it went down a tick, but not much. We were told it needed to be 55-65 PSI.

There is no issues when starting, and dash lights do not "flash on/off" so figured it was not ignition switch like reviews I read said it would do if that was the issue.


Jun 5, 2019 at 5:20 PM
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ASEMASTER6371
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Do not assume anything. The ignition switch could be opening internally on just one wire that powers the PCM.

I would call the dealer and give the service department your VIN number and see if there are any open recalls. There were recalls on the ignition switch but it was restricted to certain VIN numbers.

Roy
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Jun 5, 2019 at 5:30 PM
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RJNAGEL
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We replaced the ignition switch on the 8th of June and it had been working perfectly. until this morning when it stalled again. So apparently that latest part did not fix the stalling issue. Luckily, my son was pulling into a parking lot at work when it stalled so he was off the highway.

Know of anything else we can attempt as we are stumped!
Jun 26, 2019 at 4:21 AM
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ASEMASTER6371
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The other possible issue is the crank sensor.

Roy

CRANKSHAFT POSITION (CKP) SENSOR REPLACEMENT

REMOVAL PROCEDURE


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1. Disconnect the negative battery cable.
2. Raise and support the vehicle. Refer to Vehicle Lifting.
3. Remove the crankshaft harmonic balancer.
4. Disconnect the crankshaft position (CKP) sensor electrical connector.
5. Remove the CKP sensor shield (1). DO NOT use a pry bar.


imageOpen In New TabZoom/Print

6. Remove the CKP sensor studs.
7. Remove the CKP sensor.
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Jun 26, 2019 at 4:36 AM
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RJNAGEL
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See above at the start of this thread. That has already been replaced, back in February. Stalled immediately following the test drive after replacing. Actually, we replaced it twice as the first one was a bad part, so had to take it all apart and do it again! Easier the second time around at least!

Jun 26, 2019 at 5:29 AM
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ASEMASTER6371
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That was February and this is now. I would not assume it is good at all.

Roy
Jun 26, 2019 at 6:40 AM
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RJNAGEL
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But the car had not been driven other than test drives after replacing parts as it continued to stall so we'd keep it parked, then the 14 days it was running fine after replacing the ignition switch. Surely the new crankshaft position sensor would not go bad with very few miles on it.
Jun 27, 2019 at 4:37 AM
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ASEMASTER6371
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Okay, again, I would not assume anything.

Are there any codes set?

Roy
Jun 27, 2019 at 4:39 AM
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RJNAGEL
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It has never thrown a code. This is why this has been a very difficult fix since last October. A code would have been ever so helpful!
Jun 27, 2019 at 4:48 AM
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ASEMASTER6371
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I understand. A crank sensor can be doing this without throwing a code.

You need to monitor live data to see if the RPM falls out when the event happens.

Roy
Jun 27, 2019 at 6:37 AM
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RJNAGEL
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It runs about 900 rpm when stopped or parked and idling, and 1100 rpm's when driving once settled into to constant speed. It does not waiver when stalling, it literally goes from the higher number to 0, dropping just that quick. And, the car is so quiet, you do not know when it stalls, just when you press the gas it no longer wants to go as engine is dead, thus watching the rpm's as much as the road at times when driving....
Jul 2, 2019 at 3:47 AM
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ASEMASTER6371
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The fact the RPM is dropping out that quickly tells me it is related to the crank sensor.

Roy
Jul 2, 2019 at 4:59 AM
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RJNAGEL
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Replaced for a third time and has stalled at least 4 times since. Twice on me, however, it has additionally chugged and the RPM's were bouncing between 300-900 RPM's and I was able to get it to come out of it and not stall but not letting up off the gas. One of those times, it was in park idling as I was talking to a coach at school and it had never done that in park before, only while driving down the road.
Aug 12, 2019 at 11:56 AM
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RJNAGEL
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and yet again, still not throwing a code which would make life so much easier!! My son was wanting to take his car to college with him, but with having to drive a distance and on interstates, do not want to risk any issues.
Aug 12, 2019 at 11:58 AM
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ASEMASTER6371
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What brand sensor did you use?

Roy
Aug 12, 2019 at 12:34 PM
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RJNAGEL
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AC Delco last 2 of 3.
Aug 12, 2019 at 12:45 PM
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ASEMASTER6371
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Do you have a scan tool that can read the sensor while driving and during the stalling? Check and see if the RPM reading is dropping out.

https://www.2carpros.com/articles/engine-stalls

Roy
Aug 12, 2019 at 1:01 PM