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Discussion Starter #1
I have a 1999(98.5) F-350 SD 7.3 DRW, The last month or so I have been experiencing a intermittent rough idle and bucking while the accelerator is depressed, most noticable at 45-55mph and while accelerating. every once in awhile the truck will run completely fine as if no problem existed. I was originally told by the dealership it was an injector issue but that turned out to be false, but I had already replaced the number 8 and 2 injector along with the drivers side UVC harness. The problem never went away, just troubleshooting I replaced the IDM, the IPR, CPS sensor, EBP tube and cleaned that sensor, battery cables and checked for any chaffing of wires. Everything is good and checks out. Have run every test on AE and everything seems to check out just fine with the exception of these codes P-0236 turbocharger boost sensor circuit range/perfomance, P-0500 Vehicle Speed Sensor A, and B1203 Fuel Sender circuit short to battery. The last two only come up if I select "All" at the startup of the AE program, the first code only comes up if I select "Current." I am not a mechanic by any means and my knowledge is pretty limited on how to check or correct these codes further. Can someone please explain these codes to me and how/where to find a solution to this and how it relates to the bucking and rough idle?
 

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so when you do a buzz test you can hear every single injector buzzing? what about a cylinder contribution test? does that come back ok? a skipping or bucking is usually a dead hole when commonly a UVCH. you could check under the valve cover to make sure the injectors are all plugged in correctly, human error cant be factored out.

another way to diag is get an infrared laser and shoot the cylinder, see which cylinder is cooler after a run where you notice it is skipping/bucking. just pull over real quick and shoot the manifolds 1 at a time.
 

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Vtwinrunning
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I GOT A 1999 EARLY ALSO, NEVER HAD A PROBLEM WITH IT AT 250K, YOU GOT AN AUTOMATIC OR MANUAL TRANNY. OFF THE THREAD HERE BUT I GOT A TS PERFORMANCE CHIP 6 POSITION FOR SALE FOR AN EARLY 99 MANUAL.
DAVE AT 763-213-3670 GOOD LUCK ON YOUR BUCKING PROBLEM, YOU MAY HAVE A LOOSE INJECTOR HARNESS ON ONE BANK OR THE OTHER.
 

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can you throttle past the buck at all with out downshifting to a smoother engine?

Dave, please type in lower caps and feel free to post your chip of sale in the classifieds as i dont feel its appropriate here.
 

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I GOT A 1999 EARLY ALSO, NEVER HAD A PROBLEM WITH IT AT 250K, YOU GOT AN AUTOMATIC OR MANUAL TRANNY. OFF THE THREAD HERE BUT I GOT A TS PERFORMANCE CHIP 6 POSITION FOR SALE FOR AN EARLY 99 MANUAL.
DAVE AT 763-213-3670 GOOD LUCK ON YOUR BUCKING PROBLEM, YOU MAY HAVE A LOOSE INJECTOR HARNESS ON ONE BANK OR THE OTHER.
Off topic yet again...Pomrenke as in Bering Sea Gold?
 

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Discussion Starter #6
UVCH harness on both sides are new, yes I can hear all 8 injectors buzzing and they all buzz with the same strong tone, no weak or low buzz, cylinder contribution test comes back intermittently with #8 but only rarely, all the injectors are correctly plugged in, its an automatic transmission and no I can throttle past it to a smoother engine
 

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Did you ever figure out what was causing the bucking? I am having the exact same symptoms in my 1995 7.3. I just replaced both UCVH's and injector two and am experiencing the same problem, the truck runs with much more power with the new injector but it will still buck around 2800-3000 rpms, possibly right when it should shift so I'm expecting maybe torque converter not ingaging? I'm also having no codes thrown, and advice will be much appreciated, thanks!
 

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I have an 03 7.3 that had the same issue it Buzz tested fine on all 8 but it still ended up being injector stiction. Throw some hot shot secret in there with an oil change, should clear it up within 1000 miles
 

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whistle tits
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My 97 has been doing the same thing since the day I went to e fuel. Ive been slowly tracing the problem down, and have narrowed it down to a cps issue, cps wiring issue, or uvch/wiring issue.

For yall experiencing this, is it almost like a Rev limiter? Mine will buck so violently it chirps the tires.
 

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whistle tits
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I have a 1999(98.5) F-350 SD 7.3 DRW, The last month or so I have been experiencing a intermittent rough idle and bucking while the accelerator is depressed, most noticable at 45-55mph and while accelerating. every once in awhile the truck will run completely fine as if no problem existed. I was originally told by the dealership it was an injector issue but that turned out to be false, but I had already replaced the number 8 and 2 injector along with the drivers side UVC harness. The problem never went away, just troubleshooting I replaced the IDM, the IPR, CPS sensor, EBP tube and cleaned that sensor, battery cables and checked for any chaffing of wires. Everything is good and checks out. Have run every test on AE and everything seems to check out just fine with the exception of these codes P-0236 turbocharger boost sensor circuit range/perfomance, P-0500 Vehicle Speed Sensor A, and B1203 Fuel Sender circuit short to battery. The last two only come up if I select "All" at the startup of the AE program, the first code only comes up if I select "Current." I am not a mechanic by any means and my knowledge is pretty limited on how to check or correct these codes further. Can someone please explain these codes to me and how/where to find a solution to this and how it relates to the bucking and rough idle?
Vss can cause weird issues.
 

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the vehicle speed sensor will deff cause an issue but has any of you tried a new throttle pedal sensor? its just a potentiometer style sensor and can get burn or weak spots in the sweep and cause a weak signal in certain spots. maybe something to check.
 

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My brother is having this issue as well. It has the grey IH cps, swapped to the ford grey and it got worse. Swapped in a known good TPS no change. Also replaced the VSS as well. tired of tossing parts at it.
 

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whistle tits
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I swapped in an original black cps after a grey and dark blue ford cps, and for now, the issue has quit.
 
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