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possibly the injectors?

1720 Views 8 Replies 3 Participants Last post by  RT
i just got on R&R here last week. packed up the truck and headed home west to western PA. on the way the ol girl was bucking pretty violently once it hit over 35 mph up until about 65. to the point where i had to turn off OD and let the rpms stay high until i got to highway speeds. all the while on heavy accelerating it sounded like it was missing mixed with a little white smoke.

well lately its been a bugger to get started. usually it takes a good 10 seconds of cranking, followed by the romps and alot of white smoke.

this morning i was pulling up to a stop light and it was fine, on take off it stuttered with an rpm drop and finally picked back up, i almost thought it was going to stall. well its been doing that all day now, but only when its warmed up.

im starting to heavily suspect the injectors, but i wanted to get some other opinions. Thanks guys,

Early1999 f250, ext cab long bed, 325k miles.
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Well, that's a lot of miles - are they the original injectors? I would want to do some testing before you jumped at expensive parts. Do you have access to AutoEnginuity? Your symptoms could be explained by a lot of little things - such as the IPR, ICP sensor, or torn injector o-rings. How is your oil? Any way to check fuel pressure? I'd check those first - could be a $2 repair...

If you don't have immediate access to the scanner - pull your ICP sensor wire and give it a try. Check to make sure there isn't any oil on the sensor or harness.
That big metal cylinder is the coil. It energizes to move the plunger inside the IPR valve. If the cylinder isn't firmly situated by the tin nut on the back, it will give you all sorts of codes and running issues.

If it were me, I'd clear all your codes first. Then get the IPR coil in place (or just replace it) and then run the scan again. That will probably clear up everything.
This might be a good read for you. Go to Diesel Technician Society and scroll down to the bottom where you find "Technician High Pressure Pump Guide For The 7.3 Power Stroke Engine"

What you are describing is the PCM having to give more and more juice to the IPR in order to achieve the desired ICP sensor level (injector pressure) - that would tell you the IPR is not working properly or you have a leak in the high pressure oil system (injector o-rings) - the ICP sensor appears to be responding appropriately.
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