Stumble/Hesitation AND stalling: *solved, fuel pump*

[jeremiahm]

I have done it twice. I can't take the beating of the concrete on my back so cutting a hole is worth it. I hit the cuts on the money this time so it came out nice. I plan on keeping it a while so I may need to use it again... This is on my 207 Yukon XL Denali.

 

[bdbull]

I replaced my fuel pump this weekend as well. Had the rough idle at stops, also a spike in RPM when coming to a stop (shift to 1st?) and had experienced some stalls and crank/no starts the last two weeks, including a tow. 3 days of driving and idle smooth and the spike in RPM is virtually gone, no stalls either. My MPG seems to be +1 as well. Pump was making some noise that was hard to notice until I could get close to it (I cut a hole in the floor). New pump is almost silent. Used same Delphi pump as @Geotrash. Truck has 150k on it.

I have a rough idle on my '10 Avalanche as well. Been battling it for a long time now with no resolution. No codes, no stalls, but it sure feels like it's just a smidge from stalling when I'm sitting at a light. I've also experienced an issue that I think might be the same as your "spike in RPM when coming to a stop." There have been times when coming to a stop, right before finally stopping, where it seems like the truck tries to accelerate instead of decelerate. I haven't actually noticed the RPM's when it happens, but it makes sense. I do know it scared the ever living snot out of my teenager as he's learning to drive.

Think I'm gonna look into swapping out the fuel pump and cross my fingers that will fix it. I've got 210k miles and as far as I know, the fuel pump is original to the truck.

btw, here is a video of my RPM gauge I took yesterday while sitting at a light. You can see it jumping around as I just sit there.

 

[swathdiver]

I have a rough idle on my '10 Avalanche as well. Been battling it for a long time now with no resolution. No codes, no stalls, but it sure feels like it's just a smidge from stalling when I'm sitting at a light. I've also experienced an issue that I think might be the same as your "spike in RPM when coming to a stop." There have been times when coming to a stop, right before finally stopping, where it seems like the truck tries to accelerate instead of decelerate. I haven't actually noticed the RPM's when it happens, but it makes sense. I do know it scared the ever living snot out of my teenager as he's learning to drive.

Think I'm gonna look into swapping out the fuel pump and cross my fingers that will fix it. I've got 210k miles and as far as I know, the fuel pump is original to the truck.

btw, here is a video of my RPM gauge I took yesterday while sitting at a light. You can see it jumping around as I just sit there.

Try checking your wires. I had a wire separate from a boot and didn't know it. How old are your plugs? A Tech-2 would be nice to have to see what's going on inside.

 

[bdbull]

Try checking your wires. I had a wire separate from a boot and didn't know it. How old are your plugs? A Tech-2 would be nice to have to see what's going on inside.

Plugs and wires were replaced at 190k, so they are right at 20k. I'll check them out just in case that would be an easy fix.

 

[bdbull]

Plugs and wires were replaced at 190k, so they are right at 20k. I'll check them out just in case that would be an easy fix.

Haven't gotten to check everything yet, but it did it sitting in park in a parking lot just now. So it looks like it's not just while in drive. Actually thought it was gonna shut off.

 

[Fless]

Before you go and change that fuel pump out on a guess, why not rent a fuel pressure gauge and do the test? Best case it might rule it out.

 

[bdbull]

Before you go and change that fuel pump out on a guess, why not rent a fuel pressure gauge and do the test? Best case it might rule it out.

Is it sufficient to use a OBD2 reader to test that or would it be better to rent a gauge from the parts store?

 

[Fless]

Best to rent the gauge and check it at the fuel rail.

 

[89Suburban]

I have done it twice. I can't take the beating of the concrete on my back so cutting a hole is worth it. I hit the cuts on the money this time so it came out nice. I plan on keeping it a while so I may need to use it again... This is on my 207 Yukon XL Denali.

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Thanks for taking the time to post the pics and measurements for the fuel pump access door/panel.

 

[OR VietVet]

When you check that fuel pressure gauge, get a long enough adaptor hose to allow for you to bring out at back of hood and tape to w/s to watch thru the whole driving/idling process.

You are actually pretty lucky that members are responding to this for you because the OP has already posted "Solved", on their thread.