1028 Acting funny at highway speeds.

[musclecars664]

This just started happening recently, but when im traveling at speeds above 40 MPH the truck acts goofy. It will cruise fine for a little bit but then it will just start losing power randomly and slowing down. When i push the pedal down to regain speed nothing happens till it gets to about half throttle, then the motor revs. the whole truck bangs when this happens cause its putting torque back on the rest of drive train. I have driven around town a couple times and it has no problems accelerating or shifting through all three gears. just acts funny on the highway.

I did just replace the fuel filter which didn't help and the most recent thing i have done besides that is turn my IP up 1/8 of a turn. the truck has 38K miles, but could this be the injection pump going or a fuel problem?

Thanks, James

 

[tamecrow]

Did you look at the check valve on the return side of the pump for debris? If there is debris there, your pump is probably on it's way out.

 

[jimmy-90]

Hey neighbor. I had a problem like that not too long ago that turned out to be a leaking fuel line. Hopefully it is not the check ball in the return line like stated above.

 

[ODdave]

the motor revs but the truck dosnt accelerate? if so did you check the trans fluid?

 

[musclecars664]

I did check the tranny fluid and that was fine. its just kind of hard to explain. its like its lagging. there is zero throttle response when this happens until the pedal is depressed quite a bit, then the motor revs. almost like the truck isnt getting any fuel until the pedal is half way down.

Thanks for the responses so far. ill try to take a look at the check valve tomorrow.

 

[musclecars664]

i just went and puller the check valve off. seems to be pretty clean. the spring is working smoothly. i looked in the hole to the pump, and that looks clean also. i guess ill start checking the lines. does a leak from a fuel line have to be bad to cause a problem like this or could it be something caused by a line thats just letting fuel slowly bleed through?

 

[jimmy-90]

Just to start from the begening with mine. I started out with a pretty bad leak in my fuel filter base which is probly not your problem if the truck starts without excessive cranking. I converted it to a racor spin on and that fixed that. later on mine started doing the sputtering with a dead throttle petal that would come back after some stomping and feathering. I was at a total loss as to what was wrong with it because it would only do it while it was running up the road and I had already inspected the check ball and it was fine. One day it did that near my house and I looked at it right after it did it and noticed alot of fuel had leaked around the fuel tank. I had just converted my truck to a flat bed so it was very easy to see it at that point. Once I replaced that small piece of line comming out of the fuel tank it has ran good every since. Im sure the reason I wasn't able to spot the leak easily was because it would only do it when I was driving up the road and by the time I made it back to my driveway the leaked fuel had evaporated. Anyhow I hope your problem is something simple like that and good luck.

 

[musclecars664]

OK i think i solved my problem. i searched all the lines pretty well and i couldn't see anything leaking except for the lift pump, and it was leaking pretty bad. I went to NAPA and bought a new pump, put it on and couldn't get it to pump fuel to save our lives. tried everything and came to the conclusion that the NAPA pump was defective. I went to Carquest and bought what they had and it was the exact same thing, same part number an everything. the only difference between the two was that the Napa pump had about 3/4 inch of play in the arm before the pump started to engage, and the Carquest one hardly had any. So we swapped the NAPA pump out for the Carquest pump and it seems fine now. no more surging issues on the highway and seems like throttle response is a little better, but maybe thats just mental.lol

James

 

[WARWAG]

If your problems started after you turned the IP up an 1/8th of a turn I would think that caused your problems.