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GMC Envoy Start Stall Idle Problems
alabamamaddog
Member Posts: 4
Starting about a year ago, my 2002 Envoy began to idle very roughly when in drive. Once the engine warms up to the normal operating temperature, the rough idle stops.
It idles smoothly when in park or neutral, even when it is first started.
I have used Seafoam and STP fuel injector cleaners, with no noticeable results.
Any suggestions?
See also: Envoy/Trailblazer Stalls at Idle With the A/C Or Heat On
It idles smoothly when in park or neutral, even when it is first started.
I have used Seafoam and STP fuel injector cleaners, with no noticeable results.
Any suggestions?
See also: Envoy/Trailblazer Stalls at Idle With the A/C Or Heat On
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Comments
I would recommend taking your vehicle to your dealer of choice. Please keep me updated on your situation.
Christina
GM Customer Service
How are things going with your vehicle?
Christina
GM Customer Service
I tried the fixes others in this thread have tried as I actually enjoy working on my own vehicles and have a pretty good understanding of how they work. However I could not solve the issue on my own. Fortunately, I had a dealer that I was real happy with when I owned my LS1 Camaro that had helped me with mechanical problem then. Took it to them.
When the vacuum line is activated for the engine, such as when the air or heat was on, the truck would die at idle (when in gear only, would not die if in neutral). I had changed the battery and on the Envoys it resets all previously stored air/ fuel, idle, etc info that the computer had previously gathered about the motor. The truck is programmed with a starter program to get the truck running then it stores its own information according to the individual motor. Each motor is different and requires different parameters to run depend on anything from altitude to your personal driving habits.
The truck is supposed to reteach itself the fine tune parameters within minutes. It was not. The tech said nothing will show up on their computer because the check engine light is not on. The tech has to have some kind of motor knowledge to spot this, not just the ability to read what the computer is telling him. All the tech had to do was let his GM computer overide the Envoy computer to reprogram it. All I was charged was the initial diagnostic fee since nothing else had to be hooked up and done. That was two years ago and I have had no problems since.
This tech also did me right with my Camaro and this is the explanation I got when he fixed my Envoy.
I cleaned the throttle body with a spray cleaner, and cleaned my MAP sensor then changed my air cleaner, now it runs and idles fine..Problem solved. Hope this helps.
Also you will need to reset the computer and check engine light, just disconnect the pos post to the battery for ten minutes the reconnect post and turn your ignition key on and off three times to reset the computer and clear codes.
A few months ago, I noticed that my oil pressure gauge would drop to "nothing" for a few minutes, then pop back up to normal. When it dropped to nothing, I could "rev" up the engine and the pressure would return to normal, let it idle and the pressure would go back down. The only "light" on the instrument panel that would show up would be the "Gauge" light...
I had a tune up, fuel injector cleaned, oil change EVERY 3000, spark plug changed (no wires on this vehicle), radiator flush, transmission flush.... All at a substantial price and no solution still. ALSO, the truck runs fairly rough and continues to get worse. When idling the truck will always die at some point. RPMs measure approx 600-900 idling. Current mileage is 152,000.
Any help would be GREATLY appreciated!!!!!
Just wanted to say thanks
Total cost ( 0 )
Otherwise the parts from GMC cost a small fortune.
Sarah
GM Customer Service
We get home and next day.... it takes 2 or 3 cranks to get it to start. I even asked the service mgr if they'd: check fuel line pressure(s), computer modules, etc. We even had the fuel filter changed... it still doesn't start w/o 2 or 3 tries. Any thoughts? Buy a Ford?
Got a call about 2 hours later and he said my fuel line was losing all pressure after they had the engine sit. So we replaced fuel pump. Total cost for parts & labor was $794.
Finally got the issue fixed. Yeah.... a bit costly but it now works. I might've saved a hundred bucks or so if I ordered part online but there's cost & then there's convenience. We needed this fixed ASAP so we paid the bill.
As for the low oil pressure , that was fixed by replacing the pressure sensor located near the oil filter. Good Luck!
We took our Envoy to a local independent garage because the GMC Dealership service was ineffective (they put it on the machine and found nothing). So I took it to a popular indy garage and explained to the owner what the problem was. He said the first thing he would do is run a fuel pressure test to see if the fuel pressure would stay constant. Said it would take about hour or so to do that. Turns out that the fuel pressure would drop and continue to drop. RECOMMENDED ACTION: Replace Fuel Pump.
Cost including labor: $800 approx +/- with OEM parts.
The owner told me that fuel pressure is a likely culprit considering the age of the vehicle. I had previously had the fuel filter replaced and the fuel line inspected at PEP Boys so it seemed reasonable to consider the fuel pump issue. After the Fuel Pump replacement, the Envoy starts up as if new and has been running fine.
Hope this helps!
We started to have the same issue around June last year and got our fuel pump replaced as well. Luckily there was a recall on it. If you didn't get reimbursed for it you should definitely look into it. Bring your receipt to the dealership and get your money back.
So after our fuel pump was replaced the issue came back in December. Our first trip to our local GM repair service center, we were told that we needed our throttle body cleaned out ($320) and that seemed to work for about a month. We were in the middle of downtown San Francisco when the issue decided to come back. I had to pull over on a busy street and this cop decides he wants to shine his light on me to get my attention and tells me to move or we can move it for you. I have my whole family with me and waited about 5 mins to start it up again. We continued further in the busy streets of SF and it happened again. This time I waited about 10 mins and was afraid that during our 30 minute drive back home, it would happen again on the freeway. Luckily it didn't.
Our 2nd trip back to the GM repair service center, they had no clue what was going on and had to contact their tech support. What they told me next was not what I wanted to hear. They said that it could be the ECU that's causing the problem, due to high voltage readings and after replacing that if the issue comes back they will need to replace the throttle body. So basically they were telling me that after we replace the ECU we will be putting your family in danger if you decide to drive this vehicle, because we're just throwing darts in the dark here. We ended up agreeing to get the ECU replaced and they tried to charge me over $800 but after some haggling and complaining they agreed to give us some assistance and brought it down to $500. So now the total for this same issue is up to $825.
Replacing the ECU only lasted 3 weeks. This time I was in a drive trough at 9pm with my family and the neighborhood did not look too friendly. There were bums in the parking lot begging for money. I will be bringing the vehicle back to them tomorrow and see what they have to say. This should be interesting.
Look under the glove box at the passengers feet. A small servo motor that turns hot and cold air valve in the heater box. Pull the small flat motor off and see if the shaft is jammed.. (if jammed, the shaft will not turn when you moved the temperature selector knob from hot to cold.
You can manually open and close the door, you just have to do so every time you want the heat/air to work..
This link shows how to check the diverter door