Hey folks. I could use some help. I'm working on my mom's Venture. Has about 85k miles on it. Well maintained. She was having intermittent stalling along with a rough idle, revving up and down in park. I replaced a lot of parts after watching videos and reading posts. The van runs really well now and doesn't kick out any more codes. Original code was P0300 and a code related to the thermostat. The only problem we're having now is that it will occasionally stall out at a stop sign or light. Occasionally but pretty routinely. Starts right back up every time but sadly stalls out on her. I've probably replaced virtually all key components; plugs, wires, coils, coil control unit (below coils) both 02 sensors, EGR Valve, Fuel pressure regulator, IAC valve, thermostat, fuel filter, removed and cleaned out throttle body and MAF, new air filter, PCV valve, TPS, and replaced most of the vacuum hoses.

Phew, any thoughts on what could still be causing the stalling issue?

I had heard that I may need to reset some things in the computer after replacing some of the parts listed above but unclear about that or if that really needs to be done. Some have said the computer will self correct and no resets are necessary.

Scratching my head on this one.

Appreciate any suggestions. Mom loves her van.

Thanks everyone

 

It sure looks like you've replaced a lot of stuff. When I had a rough engine, my problem turned out to be the 24X front crank sensor behind the harmonic balancer. https://chevroletforum.com/forum/ven...ration-100802/

 

Thanks Photon440. I was hoping for more folks chiming in as this seems to be an issue with these vehicles/engines as they age. The car actually idles well and drives great. It just seems to stall out at idle at a stop sign or stop light a couple of times while driving the van. Weird. I was thinking of changing the cam position sensor. Unfortunately the computer isn't kicking out any codes which makes it very hard to track down.

 

I had the same problem on my venture, it was the hose from the rear valve cover that goes to the intake hose. Its under the coil bracket.

 

Thanks Ventureguy. I was hoping more people would chime in as this does seem to be a common problem with this engine. It turns out that was one of the many parts I replaced since the grommet that went into the valve cover was pretty mangled. So that's already been replaced. Still having the stalling issue daily The car will restart every time. So odd.

Keep it coming. Maybe we can hit something I didn't do.

One additional question, does any of the electronic parts require any kind of computer reset? I replaced the IAC, TPS, Coils & control control unit below the coils, fuel pressure regulator, tempature sensor etc.???

Thanks everyone

 

When you mentioned in your first post that you replaced the fuel pressure regulator, was it just because you were replacing everything or was it faulty? Did you do a fuel pressure test? Has the pump in the tank been replaced? I had replaced my pump because it wouldn't hold pressure - starting out correctly and then dropping off after a few minutes but not showing an OBDII code. Turns out I had other issues too, but the pump was part of the puzzle.

 

Hi Photon440. I was methodically replacing parts item by item until I found the problem. It turns out that the fuel pressure regulator was the very last thing I replaced and when I did that, the engine started running dramatically better, almost as if that was the actual problem. However, as my mom started driving it she noticed that it would stall out occasionally at a light or stop sign. It almost seems as if the RPM is too low at idle in gear, however I don't believe that it's adjustable and I don't know if that's really the issue.

The tank/pump have not been replaced. I'm hesitant to go after that since it's a really big job and aside from the stalling at lights, it drives great.

The only other clarity I have is that it seems to only do it when the engine is warmed up, not when it's cold but that may not have any bearing on the problem.

I also have not done a fuel pressure test. Do you think that is a possibility keeping in mind again that it actually drives really well??

Tough one.

Thanks all for trying to help me sort this out.

Mom loves her van

 

Sorry, I don't have any other answers to offer. The only insight is that you have some of the same problems I had, in that it would run well when cold but the issues appeared after warming up.

There are a couple of things that change as the engine warms up; while cold there is fuel enrichment to act like a choke on a carburetor, so it's running leaner when warm. Also, the EGR valve doesn't operate until it warms up. Now, I know from your first post that you've changed the EGR and cleaned the throttle body so I'm just throwing that out there as a possible lead.

You may be able to physically bend the throttle stop to force the idle speed a little higher, but that might cause a harsh engagement from neutral to drive.

 

Thanks. I was even thinking maybe dirty injectors, but if they were, then I think it would run rather crappy which it doesn't.

Hmmm. Still scratching my head. Thanks for all the input.