running rough after warming up, with bizarre symptoms some help please

[67caprice427]

Alright, here goes: bought a 1028 from fleabay, and it's been my daily/only driver for a year and 10k miles, with little to no problems. I do regular p.m.'s, check under the hood often, hopefully to spot any potential problems, and don't modify or monkey around under there. I was driving home Thurs., and while approaching a traffic light, I could feel it idling very slow, not shutting off, just very slow. Power was so weak on acceleration, a urban outdoorsman was able to outrun me across the intersection. I barely made it over the overpass & r/r tracks, and limped home. After much reading, the problem seemed to point to a failing lift pump and/or clogged fuel filter. On Sat., I changed both per the tm, and it cranked and ran on the second try. I let it idle for 15-20 min., ran perfect. On Sunday, drove all over the place, shut it off, cranked it up, no problems-ran great. Today, drove it to work this am, about 10 miles from home, same problem reappeared; very slow acceleration up to 25 mph, then better but not great, but it ran fine at 40-45 mph. Made it to work, it cooled off all day. Left this pm, took the highway home, since 40-45 was fine, maybe 50ish would be fine. Again, about 10 miles from work, I could feel the power dropping off with speed on the "hills" down to 30-35, and back up to 40-45 on the "flats", then the gas pedal gets sucked to the floor, but speed remains about 35ish. I cannot wiggle the pedal from the floor, so I just keep driving, but figure I need to come up with a plan. I throw the truck in neutral to see where the rpms are, it starts to free rev, so I drop it back in gear and shut it down while pulling over. The gas pedal slowly rises by itself from the floor, when it finishes, I try and crank it. It runs for a second and dies. While I'm waiting for a wrecker, I periodically try and start it. By the time the wrecker comes, it's running; rough, but running. The wrecker drops it off here at the house, and I can drive it around the yard, and under the carport. It's running rough, but I would bet when it cools completely, it will run fine until it warms up thoroughly, then back to the same problem. WHAT THE !@#$ is it? I need to keep it running until the end of the year, if possible. Any suggestions or solutions are greatly appreciated. Thanks, Henry

 

[Recovry4x4]

The pedal getting sucked down is weird as heck. Some of the symptoms suggest a clogging sock in the tank but others do not. Make sure you take a good look at the accelerator pedal cable too.

 

[iacucv]

I'm nowhere near as knowledgable as many here, who I'm sure will be along shortly, but I'm also thinking clogged fuel pick up sock, or injection pump has one foot out the door. I have no idea, but the pedal being "sucked" to the floor..... Possibly some kind of vacuum created from a failing IP? Idk, let the experts weigh in and hope for the cheaper fix.

 

[67caprice427]

if the weather happens to clear up, I want to look at the throttle cable, filter assembly, ip area as well. I probably won't be able to thoroughly look underneath until this weekend, between my work hrs, and the weather, laying in water while shining a light looking at fuel lines, just doesn't hold much appeal for me.

 

[cucvrus]

My guess as always is the injection pump is failing. I would have it rebuilt and replace the lift pump while you are at it. Blow compressed air back thru the fuel tank feed hose. That will clear the sock. In the future plan on removing the tank and replacing or eliminating the sock. I would say the injection pump because that has always been my experience and the symptoms you described are about the same as my experience at pump failure time. Never happened far from home. Because I never took one far from home until I changed the injection pump. Do it now before it is dead cold and you are stranded at night in the rain. About 4 hours time and $350. in parts + gaskets and you are good.

 

[richingalveston]

Is there the possibility that the pedal just stuck on the floor since you had it floored and just slowly rose. I do not believe it is possible for the IP to pull the pedal. It is highly possible that in trying to get to max power the pedal being pressed to the floor stuck and due to poor cable slowly released.

I would definitely guess that your IP is going south and normally does pretty fast once you get the power loss like you describe. Normally within a week it will only idle and have zero power and after that it will no longer start.

Once a fuel sock clogs it stays clogged. You can blow air though it backwards for a temp fix but otherwise it does not lead to an intermittent problem.

IP is not hard to do and can be done in one day however you will be down for a week or two sending the unit off to be rebuilt. Due to what has to be removed to get to it, I would recommend a water pump replacement while you are in there and go ahead and get new injectors. You have to remove the lines to replace the injectors. You have to remove the IP to remove the lines. It is best to do it all at one time. New IP new injectors.
I used badger diesel and due to work mine is half way back together. going slow because I am adding turbo also and work is not cooperating.
I believe the injectors and pump rebuild with shipping was 600. that included the fancy return lines also.

If you plan to drive it any more before you work on it go ahead and get AAA now.

good luck
Rich

 

[royalflush55]

Is it possible that you have gotten some bad diesel, maybe with some water in it? If a new filter let it run a lot better for a few miles and the diesel is bad it may have clogged the filter again. I would fully check this out before I replaced the injection pump.

 

[brazengoat06]

Agree with royalflush

 

[ssdvc]

427,

I have the same issue. I replaced the fuel filter, but that did't do it. I checked a few other things and after talking with CUCVRUS, I am removing my IP and sending it off for a rebuild. Not in my grand plan, but life moves on.