truck drops to an idle while driving

[aquifer]

I have a 2001 F-550 and have been having issues with the truck droping to an idle while driving, the service engine light come on along with the wait to start and the water in fuel, when you take your foot of the pedal it resets and will then rev up like normal, but will sometimes do this almost constently other times it will let me go many miles with no issues.

I have hooked up a scan tool and there are no codes stored,

any thoughts?

[dannanw]

cant wait for more! I am having the same issue on a friends 6.0! been chasing it for like 3 months!

[NoRalPh]

Originally Posted by aquifer

I have a 2001 F-550 and have been having issues with the truck droping to an idle while driving, the service engine light come on along with the wait to start and the water in fuel, when you take your foot of the pedal it resets and will then rev up like normal, but will sometimes do this almost constently other times it will let me go many miles with no issues.

I have hooked up a scan tool and there are no codes stored,

any thoughts?

The throttle position sensor (a rheostat on the pedal itself) has a history of failure. I'm thinking there's like a "bad spot" where it's sending an erroneous signal and drops to an idle then you reposition everything by letting up and it works again....

I got a letter from some liars (lawyers ) wanting me to join a class action suit for these bad pedals (TPS).

[Rattlesnake18]

Ok, I know this is a 7.3 thread, but is the TPS causing the WIF/GP lights to come on together and the truck fall to idle? I am the 6.0, mentioned in the 2nd post, that has the same exact symptoms, except mine will actually die on me while driving as well, from time to time.

The fact that the two lights come on together is what has many people stumped that have tried to help me diagnose the issues.

[aquifer]

Originally Posted by NoRalPh

The throttle position sensor (a rheostat on the pedal itself) has a history of failure. I'm thinking there's like a "bad spot" where it's sending an erroneous signal and drops to an idle then you reposition everything by letting up and it works again....

I got a letter from some liars (lawyers ) wanting me to join a class action suit for these bad pedals (TPS).

I replaced the complete throttle pedal assembly and it did nothing, the CPS has been replaced before, I have not tried that since this problem started, but from what I have read that will cause the truck to die, not just return to idle

[TejasDiesel]

I'd sure like to see some more suggestions on this one. I'm having almost the same issue with my 2001 F-350. Ford House solution was to replace the CPS and that didn't fix it. I did notice that if I have the cruise set, when it goes to idle and the lights come on for a second, the cruise control is reset as well (won't resume have to turn on again and set speed). No codes are being set so the good Ford mechanic is telling me he won't sling mud at it, to drive until it quits or sets a code. I hate traveling that way.
One other thing that seems noteworthy, he used the SnapOn scanner and when he ran the diagnostic and it exercised the engine, I've driven it for several miles with no cut outs. When I got it back from the Ford house after CPS replacement same thing. Drove it for couple of hundred miles and then it started acting back up again, exact same problem.
This is really a very odd problem. Hope somebody has some history with this issue.
Thanks

[7.3 SLEEPER]

i have had the problem forever. But when i change the tps it goes away for a while. in some cases a week, others a year. The ford dealer replaced 3 of them and finally said the warranty ran out, i began doing it myself. The tps' from ford just cut out, but the ones from orileys surged on me. But it always went to idle, it never died.

[TejasDiesel]

Well that does make some sense and explains the chatter about a TPS defect lawsuit. What I still scratch me head about is the cruise acting like it's been powered off and the caution lights all cycling like when you start it up. Matter of fact it seems to me like the Wait to Start light acts just like the glow plugs are being cycled. Maybe this all goes along with this TPS issue. Thanks,

[aquifer]

Well after many hours of checking all connections I could find I finally took the truck to the dealer to see if there scanner could find more info,

They pulled a code for the left bank of injectors and when they removed the head covers they found a broken oil nozzle that was sitting at the top of the engine ready to fall in and cause some major damage, they fished that out and replaced that then while they where putting the cover back on the found a burnt wire going to the IPR sensor,

with that fixed it looks like my problem has gone away, they said it would make contact every now and then causing the computer to read no oil pressure and drop it to an idle.