JediKnight2

OK...a week ago I posted up about my 2000 Chevy Venture problem. This all started when I tried to pass someone and it acted like the engine missed on me. Barely got it back to my in-laws house. We got it home and my mechanic is just aggravated with it. He did replace the fuel pump with an AC Delco pump as he said the old pump wasn't holding pressure and sometimes wasn't pumping at all.

He said the van starts and idles PERFECT..no missing, not running rough, etc. Drive the van down the road and after it warms up...it starts acting like it misses. Pull over and put it in Reverse...it doesn't miss....doesn't matter if you are in 1, 2, 3 or OD. Slip in in neutral...runs FINE with no missing. He also said sometimes it will stop if you stomp on the gas...sometimes it will stop once you put it in reverse and go back forward. They have had one of the expensive Snap-On scanners hooked onto it...NO CODES WHATSOEVER...ran the van with it connected the whole time and when it would act up...NO CODES...I think I am going to drive him to drinking with this one....the biggest problem is that it is RANDOM..it won't follow a set pattern of doing it! NOW one code constantly came up that is gone now was the P01404 I believe which was something with the EGR...there was a loose vacuum hose coming from the PCV Valve, seen below circled in blue in second photo (this is a photo of the old one so it's not kinked like that), I replaced that and the code hasn't come back..not sure if it was because of the vacuum hose or something happened with the EGR...

Any suggestions...things we have done...

I pulled off the PCV Tube on accident, replaced with NEW Circled in red in second photo
NEW AC Delco plug wires
NEW Fuel Pump
NEW Fuel Filter, FRAM which is what was on there, this was replaced a day or so before the pump...the gas had black crap in it on the gas tank side....black stuff was NOT in the tank so it was coming from the pump.
All work prior to this was just regular maintenance, I had the head gasket replaced this time last year though, had the dancing needle, the leak wasn't bad enough to have junk in my oil.





Question...replacing fuel pumps...doesn't require a PCM reset does it? The only out of ordinary thing that has happened just before this...was the van started misfiring, blinking SES light...ended up being one of the BACK plug wires had laid on the manifold and melted...we replaced all the wires...my wife RIGHT AFTER that went straight to Raleigh, NC..which is about a 2 hour drive...she said it shuttered once when she was getting off the interstate. Got to her mothers and the next time it was driven was by me...which is when the above started...

Van running fine with EGR P01404 code
I messed around and must have jiggled the wires which caused the flashing SES light and burned wire
Replaced vacuum hose running from PCV Valve, shown above circled in blue
Replaced Spark Plug Wires
drive to Raleigh
Stutter started once down there

That is the chain of events leading to this...

chevytech

u mentioned egr code if the valve is tuck open it will allow exhaust gases to run back int the motor. With the scan tool u should be able to pull up a misfire sounter to see wut cylinders are missing

JediKnight2

Van running fine with EGR P01404 code
I messed around and must have jiggled the wires which caused the flashing SES light and burned wire
Replaced vacuum hose running from PCV Valve, shown above
Replaced Spark Plug Wires
drive to Raleigh
Stutter started once down there

That is the chain of events leading to this...

Help guys....

I took the van to the local dealership to have it diagnosed today...and I have to say I am confused and...confused. As I stated before, the van had NO CODES as read by fairly top of line Snap-on Scanner....only codes it pulled up were two tensionor air bag codes...it was scanned last night before it was towed...it was started an moved into the parking place and started to pull into the bay....they come back and say there are two codes...P171 and P174. P171 is Bank 1 Lean and P174 is bank 2 lean....I had a new pcv valve and tube in the van for them to put on...no problem there. However, they say there is a transmission code being thrown...but couldn't give it to me...they told me that the engine problem was fixed...which it ISN'T if it is still bogging down after getting warm...they charge me 162 bucks for from what I understand is putting on a flipping pcv valve and pcv valve tube...then tell me there is a transmission code...which I think the Snap-on should have caught....then said I would have to pay an other 97 bucks for the transmission issue...which MAKES NO SENSE TO ME...

If the van idles fine...then warms up and bogs down under load....WITHOUT SHIFTING HARD...IN ANY GEAR...however, bogs down in ANY GEAR...except Reverse where it will not bog down but turn off if you let off the accelerator...I mean there has NEVER been any transmission shifting issues....It feels like the tech couldn't find an engine issue so passed it off to being a transmission issue...but I don't see where it COULD be a transmission issue...Again..these codes just appeared...is their scanner system that much different where it would pull codes not seen by a rather top of the line scanner by Snap-on...when this bogging down happens...the vehicle isn't bucking....it is bogging down...you can hear it in the engine......is it possible that its maybe a bad torque converter? Can they act like that? I called some transmission shops and they said...if the torque converter is locking up like that and I stop and put it in reverse...the torque converter would be locked up then to...but when it is happening...I can throw it in reverse and drive to China with it...

I looked at the exhaust at idle yesterday and it looks to be fairly strong...course at load I am unsure what it does...can I test exhaust issues by taking out the 02 before the cat?
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cj97tahoe

Hi. Did you ever get this van running properly? Mine has the same problem.
Thanks, CJ

JediKnight2

Yes, I did and it was a few things. One, I had a cracked ignition coil module..which contributed to the issue, but wasn't the issue. The MAIN thing wrong was that around the top of the engine in the middle on the back is a wiring harness....it was touching the manifold and melted some wires together. It is EASY to get this harness to be in the wrong place after a plug/plug wire change. It took out three different sensors.. crank sensor, throttle position sensor and another sensor I can't remember. What was happening is that the van was running on default settings while it was cold. When it warmed up and went into open loop mode to run off of sensor information...the computer was getting crazy data from the sensors.

Replaced the sensors, fixed the wiring and has been fine ever since.

richard_vabeach

WOW Thanks so much for your post... my mechanic and I were both REALLY scratching our heads with this too! Changed the plugs, wires, coils, and the same hose you changed from the PCV to the manifold. After each repair it would work for a while and then studder!

Is the wiring harness circled in this picture the one you refer to that melted?

BlaneR

Wow, I had the same thing on my 2002 Venture. It would only happen when warm - it would just cut out (die). Sometimes it would pick right back up, sometimes I had to pull over and try to start it a bunch of times before it would fire up, and sometimes it would have to cool for HOURS before it would start. Turns out that it was the ignition module spark timing circuit. I did have to replace the wire between it and the crank sensor (replaced that too, just for GP). Stupid wire piece was $100, as was the module. C/S sensor was only $20, but what the heck.

I've also seen the fuel pump cause the same problem, but there were no codes on this. You'd think the fuel pump would throw a code (low pressure) at least...

BlaneR

OK, I was on the road to FL last earlier this week, and the thing dies and leaves me stranded out in the middle of NOWHERE. $155 to tow it to the closest dealership, and 1.5 hrs later, this is what the guy finds...

BlaneR

That is the electrical power connector for the fuel injectors. It had gotten loose, and when it would heat up, it would cut power to the injectors. The mechanic put on a new connector and piece of wire, and I was off and running. Hasn't missed a lick since.

BTW, that connector is in that picture where someone circled it in red from 07-19-2012, 07:38 AM, I think.

richard_vabeach

Replaced the Throttle Position Sensor yesterday and everything has been great since! no more stuttering on acceleration -- even "hard shifting" I was experiencing seems to have gone away.

Sucks that I have already spend $500+ between parts and labor trying to resolve a problem that a simple $39 part caused -- but it doesn't hurt having new plugs, wires, and coils on a Venture with 174,000 miles!

I will continue to update if I have any other related issues. Thanks again, jediknight!!!