03 Yukon 5.3L Engine Stalls While Idling

[SnowDrifter]

It'll be accessible in the live data in a scan tool and will typically list a percentage number. Ex: -3.4%

There will be ST: Short term, and LT: Long term

 

[Kazap]

I have a 2003 GMC Yukon that stalls when idling. The vehicle is a 5.3L Yukon SLT with 189,000 miles. Stalling happens when the vehicle is at rest or while driving with my foot off the accelerator.

1) About 2 years ago, started stalling while coasting to a stop, but restarted easily and ran okay until the next time it stalled
2) Fuel pump and filter replaced by mechanic
3) Problem persisted
4) Replaced fuel pressure regulator and gas cap
5) Problem persisted
6) Car died and ran very roughly when restarted
7) Dealership mechanic could not find problem, but did reprogram the PMC. It ran okay when I drove it home.
8) Problem resumed
9) Determined that the car died when fuel gauge registered one quarter full
10)Wrong fuel pump and gas filter replaced by mechanic
11)Car died because ran out of gas because fuel gauge not registering level properly
12)Mechanic repaired wiring connector to fuel pump.
13)Car died on freeway and would not restart
14)Mechanic replaced cam and crank sensors (code # p0335, p0706, p1571, p1689)
15)Car ran okay for a short while and then started dying more frequently
16)I replaced throttle body with OEM part, replaced PCV valve, cleaned K&N filter and cleaned MAF.
17)Problem persisted
18)Took car to GMC dealership where technician “checked all circuits, checked maf data, ignition data, checked all ground straps and grounds at the back of the block, found the ecm internally failing”. I declined to have the technician do repairs at that time.
19)I purchased refurbished pcm programmed with my VIN and self-installed
20)Problem persists exactly the way it did before the pcm replacement. Car is undriveable. Appears to run lean. When I press the accelerator, car tach goes up and then immediately goes down.

Check for loose wire connection at steering column from key switch module or module itself.

 

[revans]

Well, the dealership let me down. Go figure. The dealership mechanic reported that the ECM was reporting internal errors. I replaced that, but it didn't work. So, I took the Yukon to my go-to repair shop, and they found the problem very quickly. There were actually two things that showed up in their analysis: 1) my new throttle body was not working correctly; 2) the drive by wire gas pedal was faulty. Both were replaced and now it drives like a new car.

The AC Delco throttle body was supposedly new, but I suspect that it was refurbished; especially considering that it was purchased for about half the price of other quoted throttle body part vendors. It's too bad that I can't return it.

I will never, never, never take my car to a dealership again. This is the second time that that repair shop found a problem that a dealership failed to find. The first time, a dealership senior mechanic told me that he could not find a cause for a problem and suggested that I sell the Yukon for parts. I found a good repair shop, and I will stick with it until the bitter end.

Is it okay to post the name of the repair shop on this forum?​

 

[Tonyrodz]

Well, the dealership let me down. Go figure. The dealership mechanic reported that the ECM was reporting internal errors. I replaced that, but it didn't work. So, I took the Yukon to my go-to repair shop, and they found the problem very quickly. There were actually two things that showed up in their analysis: 1) my new throttle body was not working correctly; 2) the drive by wire gas pedal was faulty. Both were replaced and now it drives like a new car.

The AC Delco throttle body was supposedly new, but I suspect that it was refurbished; especially considering that it was purchased for about half the price of other quoted throttle body part vendors. It's too bad that I can't return it.

I will never, never, never take my car to a dealership again. This is the second time that that repair shop found a problem that a dealership failed to find. The first time, a dealership senior mechanic told me that he could not find a cause for a problem and suggested that I sell the Yukon for parts. I found a good repair shop, and I will stick with it until the bitter end.

Is it okay to post the name of the repair shop on this forum?​

It's really hard today to find an honest, competent mechanic who can actually diagnose a problem. Most today just want to throw parts at a problem on your dime--including dealerships.

 

[Kazap]

.

 

[revans]

Well, I jumped the gun when reporting that my stalling problem was probably solved. A few days after test driving my Yukon, it started dying on me again. I took it back to my mechanic who thought he found a problem with the ABS module. According to him, a faulty ABS could cause up to three fuel injectors to fail. He ordered a new ABS, installed it, and the problem persisted. He reinstalled the old ABS module, and I didn't have to pay for that.

Now, the mechanic had told me before that the engine was occasionally misfiring on a couple of cylinders, but he did not think that it would be causing my problem. The spark plugs looked good, and the misfiring was not regular. He suggested that I should eventually replace the spark plugs with AC Delco plugs.

So when I took the Yukon back in after this latest failure, he replace the plugs in addition to cleaning the fuel injectors. I picked the vehicle up from the repair shop and haven't had a problem since. It drives and sounds really, really good, but I am not lulled into a false sense of security, yet. That is, I am not ready to say that it is fixed. I will report back in about a month, or earlier if it fails before then.

 

[revans]

Well, things got worse for my Yukon. After the throttle body was installed, the car stalled again. My mechanic replaced the gas pedal assembly. He kept it for a few days to test, and when I picked it up, it ran great, but then it stalled again. The mechanic then installed new AC Delco spark plugs and cleaned the injectors. Again, it ran great, but stalled again, and I had to have it towed. So he threw new parts at it: fuel pressure regulator and fuel relay switch. Thankfully, he did not charge me for the service. He asked that I come back and pay him if the regulator and relay fixed the problem.

The day after getting the car, it would not start. It is sitting there, a really big and expensive paper weight, until I decide what to do next. Maybe I should invest in a box of matches or sell it for scrap.

 

[SnowDrifter]

Ohhhh boy. Getting complicated now with the introduction of all the new parts.

Could you make clean list of everything replaced so far just so it's easy to keep track?

What's your fuel pressure while cranking under the no start condition?

 

[revans]

So there is a new development. In my original post, you will see "10)Wrong fuel pump and gas filter replaced by mechanic".

Everything seemed to be fine until it stalled again during rush hour traffic on a tollway. I got it started again, and limped into a parking lot. This time, I had it towed by AAA to a different repair shop; one that was AAA authorized.

The mechanics at that shop determined that my new replacement pump was not matched to my Yukon. My gas gauge indicated that I had about a half a tank of gas, but the tank was actually empty. Also, my previous mechanic stressed using OE parts, but he had put a Chinese made pump in my Yukon; with a wrong part number.

So, as the service writer at the new shop said, "I have a mechanically new car with an old dress (body)." It drives very well, but I am now waiting for it to stall again.

 

[Tonyrodz]

So there is a new development. In my original post, you will see "10)Wrong fuel pump and gas filter replaced by mechanic".

Everything seemed to be fine until it stalled again during rush hour traffic on a tollway. I got it started again, and limped into a parking lot. This time, I had it towed by AAA to a different repair shop; one that was AAA authorized.

The mechanics at that shop determined that my new replacement pump was not matched to my Yukon. My gas gauge indicated that I had about a half a tank of gas, but the tank was actually empty. Also, my previous mechanic stressed using OE parts, but he had put a Chinese made pump in my Yukon; with a wrong part number.

So, as the service writer at the new shop said, "I have a mechanically new car with an old dress (body)." It drives very well, but I am now waiting for it to stall again.

Did he charge you for an oem part? What did his receipt state, oem or aftermarket pump?