New TPS and Still havin a shudder

[Blackdog]

Well, I went ahead and replaced the TPS on my truck after much thought b/c of the price and with no surprise it didnt completely fix our problem. I noticed sometime last fall that my pedel seemed to be gettin softer than what it was when it was newer, and when I would come to almost a stop to turn off on a road my transmission wouldnt downshift outta 3rd sometimes, well now my pedel is much stiffer like it was when it was new and my transmission seems to be shifting much better now and not searching for gears like it would sometimes so the money wasnt really wasted I guess but as far as the shudder that we're all havin problems with it's stil there somewhat but not nearly as harsh. Has anyone else noticed that from those of you that have posted about this shudder that most of the trucks are 01-01. 5's, not all but most like I said. So there has to be something goin on here that the earlier trucks don't have. I've noticed that my tach is really jumpy and I know that it's supposed to fluctuate somewhat at idle, but when I'm running my cruise control I cant set there and watch my tach jump and my boost gauge move back and forth on flat road from about 6-10 psi. The truck never used to do that, and my buddies 01. 5 HO is worse than mine, heck he cant even hardly run his cruise. So my question is, would this have something to do with the cam position sensor or would it be the cruise control module, b/c every other sensor has been replaced on my truck now except the cam sensor. Please let me know your guy's input on what you think, or if any of you have tried anyting else. Take care!

 

[Blackdog]

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[Mark_Kendrick]

I have a friend with a ford that did nearly the same thing. He had a bad crankshaft position sensor. the truck would just shudder for half a second like you togled the ignition.



Later,

Mark

 

[ynot]

Old problem; NO fix. Anytime you do performance mods to an ISB, the prob gets worse (bad). The two control solenoids in the VP44 are pulse width signalled. One is timing, one is fuel. Between 1625 and 2375 rpm's, the PWM's jump back and forth between solenoids (known as "shadow pulses"), causing fuel spikes at the fueling solenoid, causing, well, what you feel while driving. VP44's after 4/01 have an isolator around the two solenoids to help correct this malady, which doesn't do squat. The only known fix to date is the P8100 conversion. Sorry. Good luck... T