Truck stalled while leaving parking lot. What may have caused this?

[rdezs]

If that was not an AC Delco or genuine GM purge solenoid, I would replace it with an oem part. Symptom is very characteristic of that solenoid acting up. Next time it stalls on her, have her hold the pedal to the floor.... If that does the trick then it's most likely that purge solenoid letting vapors flood the intake manifold, creating a flooded condition. Could very well be intermittent. They're not expensive, easy to replace quickly. And it won't throw a trouble code.

 

[Joseph Garcia]

Is this the first time that you told us that you installed a new fuel pump a month ago? Did I miss this statement somewhere buried in this thread?

 

[mikez71]

Is this the first time that you told us that you installed a new fuel pump a month ago? Did I miss this statement somewhere buried in this thread?

Just like I missed his new crank sensor! Yea one of these posts he rattled off all the usual culprits that were replaced..

My fuel pressure doesn't vary that much, FWIW, so hopefully what rdezs and j91z mention about the purge valve is it....
Mine stay between 42.2 - 43.8 when warm.. Mostly within 1psi difference. (other than hard accel or shutdown)

 

[j91z28d1]

there should be a commanded fuel pressure and an actual fuel pressure. so you can see if the pump can't keep up.

but again. you're going to have to switch cars or something and drive it for a few days to see what's going on first hand. trying to diagnose it while it's running well it very hard.

 

[testdepth]

Is this the first time that you told us that you installed a new fuel pump a month ago? Did I miss this statement somewhere buried in this thread?

@Joseph Garcia Back on post #8 I mentioned replacing it along with other parts.

 

[testdepth]

If that was not an AC Delco or genuine GM purge solenoid, I would replace it with an oem part. Symptom is very characteristic of that solenoid acting up. Next time it stalls on her, have her hold the pedal to the floor.... If that does the trick then it's most likely that purge solenoid letting vapors flood the intake manifold, creating a flooded condition. Could very well be intermittent. They're not expensive, easy to replace quickly. And it won't throw a trouble code.

@rdezs On post #8 I mentioned replacing the purge solenoid and I did use an AC Delco one. I tested it two days ago and it tested SAT.

 

[testdepth]

there should be a commanded fuel pressure and an actual fuel pressure. so you can see if the pump can't keep up.

but again. you're going to have to switch cars or something and drive it for a few days to see what's going on first hand. trying to diagnose it while it's running well it very hard.

@j91z28d1 I'm actually hoping whatever is causing this has a hard failure or falls off the truck so I know what's causing it.

 

[j91z28d1]

@j91z28d1 I'm actually hoping whatever is causing this has a hard failure or falls off the truck so I know what's causing it.

sadly I've never got the lucky haha.

 

[kbuskill]

@rdezs On post #8 I mentioned replacing the purge solenoid and I did use an AC Delco one. I tested it two days ago and it tested SAT.

When you say you tested the purge solenoid I assume you did this with your scanner and performed a pressure/seal test or whatever it's called (can't remember at the moment)?

I ask because I had some pellets from a busted charcoal canister get sucked all the way up to the purge valve and get stuck in it causing it to stay partially open.

I changed it a couple times thinking I just got a bad replacement part but upon closer inspection I saw the pellets stuck in it and holding it open. Mine would eventually throw a code for a leak in the Evap system though.

 

[testdepth]

When you say you tested the purge solenoid I assume you did this with your scanner and performed a pressure/seal test or whatever it's called (can't remember at the moment)?

I ask because I had some pellets from a busted charcoal canister get sucked all the way up to the purge valve and get stuck in it causing it to stay partially open.

I changed it a couple times thinking I just got a bad replacement part but upon closer inspection I saw the pellets stuck in it and holding it open. Mine would eventually throw a code for a leak in the Evap system though.

@kbuskill Thats what happened to mine and is the reason for installing a new one, installing a new canister and blowing the lines out when I also changed the fuel pump.

 

[swathdiver]

In the computer, in the Fuel Pump Control Module, is a line called Long Term Fuel Pump Trim. Do not confuse this with Long Term Fuel Trim found elsewhere.

I believe that this number is a sign of the pump's health. My 2009s number hovers around the 1.80s, sometimes lower. My other two trucks it hovers around 1.1.

At WOT that old pump can barely make 52-54 psi all the way up to the highway speed limit. My pickups stay at 58 psi at WOT and they make a lot more horsepower.

@testdepth Seeing your pressure bounce down to 39 psi would concern me.

Maybe you should drive the car for a few days and when you do, have all the data pulled up on your phone so you can see what's happening when it acts up.

I keep thinking about the cats too. Are your downstream O2 sensors showing steady or bouncing around when this happens?

 

[John H Daniel]

Every time I see these weird/random shut offs or weird electrical problems, I'm telling folks to check the engine bay fuse box. My issue started with what I thought were weird turn signal, hi-beam failures and then random shutdown won't start.
Turn out to be the dirty/corroded fuse box, giving poor connection to relays and cable harnesses.
see pic. Its not that hard to disassemble and clean, then all works fine
2011 Yukon btw

 

[monkeywrench71986]

This vehicle has an integrated fuse box/sub BCM had a customer that had similar issues and turned out to be a soldered in relay INSIDE fuse box, started w surging stalling and ended w a no start condition, fuse box turned out to be bad and wasn't powering up starter relay/fuel pump. Let it sit over night started would work for 30 mins or 30mi ish which ever came first and bam back to default. Because it is supplying power never threw a code. By no means am I suggesting throwing a 400.00 fuse box at it but wait till malfunction occurs and use a test light to see what's working and what's not.

 

[Jetskier77]

All this troubleshooting for random issues makes me wonder. Is there a scanner that can record live driving data? I have had weird issues over the years that are very difficult to diagnose. Several of you have mentioned monitoring the data while driving. I know very little about these scanners and am just wondering if there is a way to leave it connected and just record each trip to try and identify problems? Any recommendations as to something that might be able to do this? Thanks.

 

[mikez71]

pretty sure all good ones can.
I use hptuners, which lets you tune also.

 

[Smokin Denali]

that's a lot of new parts. all this was after the truck started acting up randomly?

but yeah, I agree with @mikez71. you'll have to be actively watching or logging while it's freaking out.

wow. original fuel filter??. change it! had similar....

 

[RET423]

If I had to guess I would say a dying fuel pump, sometimes it doesn't wake up or keep running & sometimes it will; but to verify that requires a diagnosis when it's happening because once it comes out of it the pressure will be normal

If it happens when you have no tools lay down and kick the bottom of the fuel tank, if it's a lazy pump that will usually wake it up & return things to normal until the next startup