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andy's2000 08-26-2016 11:49 PM

Jump in RPM
 
While towing my 5th trailer up a hill I step on it and the RPM's jump up but no power delivered. 2000 F350 7.3 What's happing? Thanks

Mark Kovalsky 08-27-2016 07:07 AM

How much does the RPM increase?

Chuck's First Ford 08-27-2016 07:53 AM

so many things ....


the jump in RPM's could be Normal downshift...


but ARE YOU SAYING the engine Stopped delivering the extra power??? OR the power was there but the transmission is Slipping???


air filter, fuel pump, so many things. .. More information is Needed.

andy's2000 08-27-2016 02:53 PM

The RPM increase about 500 RPM. transmission is a manual 6 speed 102k miles. Banks engine brake and edge tow chip 40 hp
The RPM increase only happens while towing my 5th wheel toy hauler very heavy my guest load about 13k pounds its like it won't let engine over speed. I'm thinking PCM because there is no ground to the GPR the EOT has a false reading.. I disconnected it to smooth out the idle.
This is what I've done so far: replaced ICP,CPS,EOT,fuel filter, Batteries, GPR, clean EBP tube, repaired VCH ( $.50 fix) and checked continuity from PCM connector to all sensors and IDM to injectors, clean oil and proper level in HPOP, checked all injectors all have correct resistance no shorted or open circuits to injectors.
I did all these things 2 year ago checked all connectors twice and it started to run correct, but started again this year. Both times these problems started I was at high elevation between 5k and 8.5k 85*to 50*F.
I'm thinking the PCM is not responding to the altitude. I'm stumped!

Mark Kovalsky 08-27-2016 07:10 PM

Thanks for telling us it's a manual trans. That would have been nice to know at the beginning. Most manual transmissions do not downshift on their own.

The PCM has NOTHING to do with the engine RPM!!!! ALL of the RPM control is YOU, via the shift lever. YOU put it in a gear and that determines the engine RPM.

Unless the clutch is slipping. That's the ONLY way the RPM can jump when YOU haven't moved the shift lever.

If the tach is showing the same RPM, but it sounds like the engine has sped up by 500 RPM, that's the engine cooling fan engaging. It's normal.

andy's2000 08-27-2016 08:05 PM

No shifting, no fan engaging. Did have problem with clutch slave valve during my last trip.


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