James Quinlan

Well at least maybe a sandwich lol. I have a 2011 Chevrolet Express 3500 LT van with the 6.0 liter engine (flex fuel) As of now I am having an usual problem as the van will at different times and under different conditions, suddenly stall out and die. Only by removing the battery cables, touching them together to clear the computer (and any codes with it if any) will it start and continue to run. It will continue to run anywhere from 2-3 minutes to as much as 3 hours (happen last Saturday) so it doesn't happen consistently and usually once it does occur it continues to do so every 2-30 minutes. This usually happens the first time from a cold start after about 30 minutes or so, whether I am driving low speeds or highway speeds. Here's a list of what I and my mechanic have done so far including the two repairs down before the issue started that may or may not have anything to do with the problem:

1.) BCM was replace a few months ago (about 2 months before this all started) due to to it failing and finding out it was under recall from GM.
2.) Fuel pump was replaced just before BCM but while it was in the shop as it was originally thought by my mechanic that the fuel pump had gone bad.
3.) Tune-up done at same time as fuel pump replacing plugs and wires. At this point my problem had not started yet but felt this info would rule out the items just mentioned.
4.) First time the engine stalled about 3 weeks ago, as well as bogging down but not stalling once right after I got it started, it coded showing the code for a faulty Cam Position Sensor which was replaced by my mechanic.
5.) It did it again but took a while as I had driven it from a cold start about 70 miles (both residential and highway speeds) and it proceeded to stall and not start until I reset the computer 6 times over a period of 45 minutes while driving no faster than 25-30 mph (working in a residential area). It than bogged down once but continued to run and made it 3 hours and another 50 miles of side streets and highway without stalling or bogging down once. Coded again with the fault code for Crank Position Sensor which was replaced by my mechanic.
6.) Drove it home from shop where it stalled and would not start with out removing battery cables and clearing computer twice.
7.) Replaced the Mass Airflow Sensor myself. Still stalled and need computer reset while at work yesterday (11 times!)
8.) Replaced Throttle Body this morning (including TPS) and again while test driving it under different speeds (and to make sure TB was relearned by PCM) it still stalled and needed computer reset. This was on a highway at about 55mph. Van is currently at my mechanic as I drove it straight back there. It was that or a can of gas and a match lol.

Lights and gauge remain on while vehicle stalls. No codes/check engine light have occurred after Crank Position Sensor was replaced except when I first replaced the MAF. Reset computer after it stalled first with new MAF and the check engine light went off but still having the same problem as mentioned above.

At this point I am at a lost as to what is causing this. It would be tolerable if it occurred once in a while but while using the van last night I had to do the cable reset 11 times in a period of an 1 hour and half just to get people home and the van back to my house. Only thing I and my mechanic can think next is possibly an intermittent fuel pressure issue or the ignition switch but since the gauges and lights stay on on the dash while it stalls the ignition switch seems unlikely. And again no codes are coming up now. Does anyone have any idea(s) on what the problem is so I can get this van back to work and not lose money everyday it's down? Any ideas, any suggestions, anything to point in the right direction would be appreciated.

StanVan

Are there any codes to read before you reset it?

James Quinlan

No no codes at all after the crank position sensor was replaced. Odd thing was today I dropped it off at the shop where it died again just as I was parking and after leaving and coming back to remove items for work i decided to see if it would even start without a reset. Sure enough it started right up and ran fine until I turned it off 10 minutes later.

kevinkpk

Sounds to me like you need to replace the ecm

canucklehead

is it a possible security system failure. The van has factory immmoblizer.

James Quinlan

The ECM is what we are thinking as well. Pigtail for fuel pump connector seems to be under recall so he is checking to see if a lose of fuel pressure occurs by driving it with dog house off and hooking up the fuel rails to his gauges and see what happens when it stalls again.

As far as the security system, which is not something we considered, how do you go about checking to see if it is work properly or not? And since the van stalled out but start3s right up with out doing anything including resetting the computer would the security system reset by itself or not? Will mention this to my mechanic.

StanVan

I'm still stumped by the lack of codes.

We have recently been discussing a device that plugs in to the OBD port, an ELM327 Bluetooth reader. Coupled with software on a smart phone, it can read info on the fuel rails in real time, as well as many other things that can be going on. That seems way more pleasant than a ride with the doghouse off.

Where are you located?

James Quinlan

Columbus/Pickerington, Ohio

Is this device available online? And I have seen some out there just never knew if they were legit diagnostic devices or just another way to get at my hard earned money lol.

StanVan

They can be somewhat fraudulent. But even the cheapest clones will read what you need.

Basically, the cheap clones are Chinese knock offs that copied an older version, so while outdated, they still work. The software can be free in some cases. I use Torque Lite, the free version of Torque. If you have the time, read "Best Upgrades Done". It a bit lengthy, but we totally covered the ELM device.

And yes, they are available on line.

StanVan

I have two of them,both Chinese clones.