Hmm. Guess what I finally convinced them to check?
Guess what they told me today? "Your fuel pump and screen are all bunged up with 'dust and rock bits'". They're changing the fuel pump...
p0171 and p0174 errors - stuck in Moab
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Guess what they told me today? "Your fuel pump and screen are all bunged up with 'dust and rock bits'". They're changing the fuel pump...
This is a link to a prior discussion of a fuel pump problem. Not sure it was ever resolved what really was the problem with that one. In my case: same issue? "off roading" dirt (favourite of the dealership)? stuff from having my aux tank on-and-off? who knows? At this point if it's fixed, I don't care
I'll post up a more complete writeup (mainly pictures), but I got the truck back to LA today - no problems at all.
It turned out it was the fuel pump. I got them to keep the part for me that they took off. I inspected it to see if it was white gunk like in the other fuel pump post. Nope. It's dust, and even small sand grains. I had A LOT of dirt in my fuel pump. The filter screen on the fuel pump was distended and hard. Most of the tubing in the pump had so much dust and very fine sand that you'd get it coming off on your fingers when you ran them in any of the parts.
So the bottom line is, this isn't a tank failure or any kind of weird E10 erosion, etc. Somehow a lot of dirt from all my desert off road driving got in there. On the one hand, my truck does get very dusty. On the other, I'm usually pretty careful getting the fuel into the tank - or so I thought. I can't think of how so much desert dirt got into the tank other than through the filler neck.
Anyway, I'll post up photos. Consensus question: is this something for engine performance now, or more like 4x4 section?
It turned out it was the fuel pump. I got them to keep the part for me that they took off. I inspected it to see if it was white gunk like in the other fuel pump post. Nope. It's dust, and even small sand grains. I had A LOT of dirt in my fuel pump. The filter screen on the fuel pump was distended and hard. Most of the tubing in the pump had so much dust and very fine sand that you'd get it coming off on your fingers when you ran them in any of the parts.
So the bottom line is, this isn't a tank failure or any kind of weird E10 erosion, etc. Somehow a lot of dirt from all my desert off road driving got in there. On the one hand, my truck does get very dusty. On the other, I'm usually pretty careful getting the fuel into the tank - or so I thought. I can't think of how so much desert dirt got into the tank other than through the filler neck.
Anyway, I'll post up photos. Consensus question: is this something for engine performance now, or more like 4x4 section?
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mir207,
I'm thinking vandalism or maybe even sabotage. However unlikely, it is still a real possibility. Along that line of thinking I have some questions:
1. Do you have a locking gas cap?
2. Could the debris have been in the tank since before you bought it? ie. Could the truck have been vandalized in the dealer's lot or en route to the dealer?
3. I'm guessing that you have used fuel cans to refuel on the trail at one time or another. Could the debris have come from one of the cans?
I'm thinking that the debris might have been in the tank for quite some time before it actually plugged up the fuel pump and caused a noticeable problem. The debris had to come from somewhere unless it was in the tank since manufacture or introduced somewhere between the factory and delivery to you. My gut instinct tells me you were a victim of vandalism. This is in line with the Occam's Razor thing. "The explanation requiring the fewest assumptions is most likely to be correct." Disgruntled employee or co-worker? Ex-wife/girlfriend? Jealous Hummer owner? Children just playing a trick on you?
Someone put it there. The question now is who and when?
My vote on where to move this thread, if at all, would be to the technical section.
I'm thinking vandalism or maybe even sabotage. However unlikely, it is still a real possibility. Along that line of thinking I have some questions:
1. Do you have a locking gas cap?
2. Could the debris have been in the tank since before you bought it? ie. Could the truck have been vandalized in the dealer's lot or en route to the dealer?
3. I'm guessing that you have used fuel cans to refuel on the trail at one time or another. Could the debris have come from one of the cans?
I'm thinking that the debris might have been in the tank for quite some time before it actually plugged up the fuel pump and caused a noticeable problem. The debris had to come from somewhere unless it was in the tank since manufacture or introduced somewhere between the factory and delivery to you. My gut instinct tells me you were a victim of vandalism. This is in line with the Occam's Razor thing. "The explanation requiring the fewest assumptions is most likely to be correct." Disgruntled employee or co-worker? Ex-wife/girlfriend? Jealous Hummer owner? Children just playing a trick on you?
Someone put it there. The question now is who and when?
My vote on where to move this thread, if at all, would be to the technical section.
Another possibility is that a gas station pump was missing or had a defective filter and allowed gunk to be pumped into your tank.
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That did cross my mind, but it would seem to be very improbable that he would fill up from a source that had this kind of problem. Possible, but not likely. This adds unnecessary complexity to the explanation which violates the Occam's razor principle. That's not to say that it could not happen, but the odds get longer when you add that kind of thing to it.
I was thinking that maybe the debris entered somehow through the vapor recovery system. Was there ever a time when a vent hose came loose or anything like that. I can't remember if he has an auxiliary fuel tank, but it could be related to that installation if he has one. Driving off road in dusty conditions with something like a loose or disconnected fuel tank breather hose could allow sand and dust to enter the tank. A loose hose or other open port should have triggered the CEL and i don't think that happened.
One thing that bugs me about the dealer's approach was that they seemed to have overlooked checking the fuel rail pressure. A low or fluctuating pressure reading should have tipped them off to the source of the problem right away. I think that dealer should reimburse him for travel expenses, air fare etc. It should not have taken this long to diagnose and fix the problem. I think I could have gotten to the bottom of it much faster, and I am not a pro mechanic in any sense. IIRC, you can get to the fuel pump through a port under the rear seat. I think you may even be able to replace the pump without removing the fuel tank. What took so long?
My money is still on the vandalism theory. The gas cans are high on my list of suspects. I would check those cans to see if there might still be some debris in them even if only a tiny amount. Just playing detective here and this is all purely speculation, nothing more. I could be way off base with this reasoning.
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a locking gas cap was one of the first things i bought when i drove the FJ home. i'm not concerned about fuel siphoning as much as i am about anything other than gas getting poured into my tank.
I posted up the photos in this thread
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Glad you finaly got it home!Hmm. Guess what I finally convinced them to check?
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