GM 3.4l v6 stalled/ what to check

[John Williams]

Hello, I have a 2005 Chevy Venture with 250k mi on the clock. Today while driving it just completely shut down. Was able to coast to a safe place and tried to restart it and it would turn over but not start. I left it sit for an hour and tried again and it started right up. Drove it home and then around the block a couple of times and it ran normal, also did a code scan and everything was normal. My first thought is the crank sensor and I see this vehicle has two. Any thoughts on if this is a logical first step and if so , is one of the crank sensors more prone to fail than the other?? Any thoughts would be much appreciated.

 

[Mooseman]

We're not well versed with this engine. @mrrsm does have some experience and hopefully will chime in.

Basic troubleshooting should be able to pinpoint what is missing between fuel and spark. Unfortunately you'll have to wait until it fails again. Check the fuel pressure and then spark. If only fuel pressure is missing, I'd be looking at a possibly failing fuel pump, which could be stopping when hot and then starts up again once cooled down. If it does stop again, try banging on the underside of the tank with a rubber mallet which may get it going again.

 

[John Williams]

We're not well versed with this engine. @mrrsm does have some experience and hopefully will chime in.

Basic troubleshooting should be able to pinpoint what is missing between fuel and spark. Unfortunately you'll have to wait until it fails again. Check the fuel pressure and then spark. If only fuel pressure is missing, I'd be looking at a possibly failing fuel pump, which could be stopping when hot and then starts up again once cooled down. If it does stop again, try banging on the underside of the tank with a rubber mallet which may get it going again.

Thanks for your reply , I appreciate it. I know this probably isn't the forum for this vehicle and engine but I have gotten so much help here in the past I thought id give it a shot.

 

[Mooseman]

And if it is the fuel pump that is stopping, make sure that power is getting to it before condemning it. Especially check the relay is it too could be failing when it gets hot.

 

[TollKeeper]

The 3400 has a couple things that will cause this issue. The MAF, ICM, CPS (Crank), CSPS (Cam), Fuel Filter, Fuel Pump, Fuel Pressure Regulator.

But I am shying away from the CSPS as it would throw a CS Correlation Code, and it would still run using the CPS.

Next time it stalls, check for spark, its the easiest thing to check and do, when the problem arrises.

 

[movietvet]

I would think that if is any of the sensors, cam and crank and MAF...etc., that would set a code. When checking for codes, be sure to check for current, pending and permanent codes.

Does sound like a fuel pump though and when I was in the shops and even now, if I do a fuel pump, I do the relay at same time. One of the things that helps speed along the fuel pump shutting down is running the fuel tank low a lot. The fuel in the tank cools the pump. Low fuel level lets the pump run hotter. I tell all people that think of 1/4 tank level as empty.

 

[mrrsm]

Welcome to GMT Nation...

The -=BEST=- 60 Degree V6 Forum to Join and Search at is:

Home - 60DegreeV6.com

This is the top level CMS page that shows all categories that hold the articles on this site

www.60degreev6.com

It has been over a decade since I was an active member there as, "60dgrzbelow0" so I am a little Rusty on the Platform... but @Mooseman's Mantra of: "Fuel, Air, Spark" with organized Diagnostics and checking out the Facts, Threads and Posts at the dedicated Link above will give you the Best Practices and Hints anywhere on the Internet. Good Luck, Brother!

 

[John Williams]

We're not well versed with this engine. @mrrsm does have some experience and hopefully will chime in.

Basic troubleshooting should be able to pinpoint what is missing between fuel and spark. Unfortunately you'll have to wait until it fails again. Check the fuel pressure and then spark. If only fuel pressure is missing, I'd be looking at a possibly failing fuel pump, which could be stopping when hot and then starts up again once cooled down. If it does stop again, try banging on the underside of the tank with a rubber mallet which may get it going again.

We're not well versed with this engine. @mrrsm does have some experience and hopefully will chime in.

Basic troubleshooting should be able to pinpoint what is missing between fuel and spark. Unfortunately you'll have to wait until it fails again. Check the fuel pressure and then spark. If only fuel pressure is missing, I'd be looking at a possibly failing fuel pump, which could be stopping when hot and then starts up again once cooled down. If it does stop again, try banging on the underside of the tank with a rubber mallet which may get it going again.

And if it is the fuel pump that is stopping, make sure that power is getting to it before condemning it. Especially check the relay is it too could be failing when it gets hot.

Thank you !!

 

[John Williams]

Welcome to GMT Nation...

The -=BEST=- 60 Degree V6 Forum to Join and Search at is:

Home - 60DegreeV6.com

This is the top level CMS page that shows all categories that hold the articles on this site

www.60degreev6.com

It has been over a decade since I was an active member there as, "60dgrzbelow0" so I am a little Rusty on the Platform... but @Mooseman's Mantra of: "Fuel, Air, Spark" with organized Diagnostics and checking out the Facts, Threads and Posts at the dedicated Link above will give you the Best Practices and Hints anywhere on the Internet. Good Luck, Brother!

Thank you, will definitely check them out.

 

[movietvet]

Welcome to GMT Nation...

The -=BEST=- 60 Degree V6 Forum to Join and Search at is:

Home - 60DegreeV6.com

This is the top level CMS page that shows all categories that hold the articles on this site

www.60degreev6.com

It has been over a decade since I was an active member there as, "60dgrzbelow0" so I am a little Rusty on the Platform... but @Mooseman's Mantra of: "Fuel, Air, Spark" with organized Diagnostics and checking out the Facts, Threads and Posts at the dedicated Link above will give you the Best Practices and Hints anywhere on the Internet. Good Luck, Brother!

Recently I was working on a 2010 F150 5.4 with a fluttering oil pressure needle on my mechanical gauge from my tool box. I wanted to see what it would say/do while driving. I went to my local O'Reilly's and they did not have extended lines to attach and read the oil pressure, in the cab while driving. They suggested to see a local, right down the street, supplier of all different kinds of sizes and lengths of lines and pressures that the lines would handle. Plus they had whatever fittings I needed and they built me 2 custom length, 8', lines with the correct fittings, for the oil pressure and fuel pressure. My cost, out the door was close to $60 total. The extended line gave me plenty of length for the oil pressure diagnostics and I know the fuel line will work too.

Since I do work out of my driveway, these 2 lines will save me so much time and guesswork. I can also get the scanner out and do it, but I wanted to SEE the fluttering needle.

 

[Mooseman]

Recently I was working on a 2010 F150 5.4 with a fluttering oil pressure needle on my mechanical gauge from my tool box. I wanted to see what it would say/do while driving. I went to my local O'Reilly's and they did not have extended lines to attach and read the oil pressure, in the cab while driving. They suggested to see a local, right down the street, supplier of all different kinds of sizes and lengths of lines and pressures that the lines would handle. Plus they had whatever fittings I needed and they built me 2 custom length, 8', lines with the correct fittings, for the oil pressure and fuel pressure. My cost, out the door was close to $60 total. The extended line gave me plenty of length for the oil pressure diagnostics and I know the fuel line will work too.

Since I do work out of my driveway, these 2 lines will save me so much time and guesswork. I can also get the scanner out and do it, but I wanted to SEE the fluttering needle.

How is oil pressure related to an engine stalling?

 

[John Williams]

How is oil pressure related to an engine stalling?

Not sure!! Vehicle doesn't have a pressure gauge.

 

[TollKeeper]

How is oil pressure related to an engine stalling?

GM used to base fuel pump power off oil pressure. This way if the engine stalled, IE in an accident, the fuel pump would shut off.

I think somewhere around in 1997 they may have stopped doing this, but I dont have access to those files anymore to verify.

 

[Mooseman]

Not sure!! Vehicle doesn't have a pressure gauge.

Even if it doesn't have a gauge, it could still have a pressure sensor and have a data PID to read actual pressure. If it's low, then it would turn on a dummy light. Or it could have just a switch for a dummy light. We have that problem with the 4.2 that uses a switch and a fake gauge. It's a high failure rate part and will throw a low oil pressure warning for no reason. I don't think it's something affecting you either way.

GM used to base fuel pump power off oil pressure. This way if the engine stalled, IE in an accident, the fuel pump would shut off.

Hmmm. I'd be weary of anything that could shut off an engine because of a loss of oil pressure (i.e. kill the engine before getting off the road safely). I would have used RPM instead or in conjunction with the oil pressure.

 

[movietvet]

How is oil pressure related to an engine stalling?

The small amount my story related to the OP's stalling problem, had to do with knowing the fuel pressure when driving and the problem occurs. I can access that info via a scanner or via a much larger gauge that I would attach to the w/s. Can easily see if the fuel pressure is steadily diminishing or just all of a sudden, the pressure drops all the way down. Harder to see that in a scanner.

I am assuming I spent too much time getting to the extended lines portion of my explanation. Sorry if I robbed you of that minute or two of your day.