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Engine/Transmission (1998.5 - 2002) engine problems

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Engine/Transmission (1994 - 1998) Help with fuel pressure fluctuation

2nd Gen Non-Engine/Transmission Gauges & night illumination

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12 black www.tcarberry@canada.com



Have 99 1ton 235 HP 3. 54 5 speed 4x4 since new has had a bucking problem at low throttle even in 2nd 3rd and 4th gear makes for very had driving down grade in town or on highway never have used more throttle then have had to . Has been dynoed at 175 RWHP. There has to be someone else that has this problem, do you have a fix????/ Chrysler was not able to identify excessive toe in for the front end from the factory!!!!!! That cost me over $4500. 00 Had to drove for over a year with out the lift pump working for they weren't able to identify that!!! I told the diesel machinic that it dynoed at 130 RWHP. His answer was "That is about right" Does any one know if they use a POT to control the gain on the op-amp from the throttle cable to increase the RPM is it putting out an poor resistance ??? CAN ANYONE PLEASE HELP??? What apiece of (*???<>@!!???)
 
2ND-Time, welcome to TDR, sorry it's not on a more positive note. Hopefully we can help you get to the root of your problem because there isn't much that is more fun that a Cummins that is running right and had the power cranked up a notch or two!



A 235hp engine should be approx 180-210hp at the wheels when it's running right, anything below 170 I'd say it needs attention. Yes the throttle is "Fly by wire," it is TPS (actually called APPS or Accelerator Pedal Position Sensor) which is basically a glorified pot. There is the potentiometer and the idle validation switch which tells the computer you aren't touching the throttle.



There is a procedure you can go through that will "reprogram" the resistance range on you throttle, so the ECM knows where WOT and idle is and everything inbetween. Unfortunately I don't recall the exact sequence and hopefully someone can jump on here and explain it.



As far as bucking, do you think there is excessive slop in the driveline? Does the engine surge badly when you hold the throttle steady? Most trucks the throttle is so touchy that you can really set up a yo-yo effect in the lower gears if you aren't real easy on it.



Where did you take your truck with the toe-in problem? Is it fixed now? Sounds like you have a terrible dealer, unfortunately there are a lot of them out there. When it comes to frontend and alignment work I suggest taking it to a shop that does alignments on ambulances, firetrucks, school buses, etc.



Hope we can get you worked through your problems. Another thought is if you can tell us what area you're in maybe one of the TDR members may live close enough to you to drop by and give you some help or at least moral support.



Vaughn
 
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12 black www.tcarberrycanada.com



Well guess I shouldn't have hit that button it was gone. Owell try again. Have to thank Kal-tire for the Info at that time on the tire problem with this info chrysler was able to fix that part of the problem from the factory but not before it had caussed alot of other wear!!!!! It only took 154 +++ kms for ME to fix this problem. I have taken it to 4 diferent dealers and I havn't been impressed with any of them. The bucking was from new and I put about 500 lbs in so drive line angle was reduced but ??? I question this bucking because idel is rough, power is low,and of the bucking . In 78 I drove one of the first 280 ZXs and it behaved the same way, the fuel was either on or off. It has no low torque in third gear it bucks instead of labouring like my 93 did, no typical diesel pull. It goes to the fuel no fuel mode.

Thank You
 
Mine has done something similar in the past. I caused it and fixed it. Try this.



Under the TPS / APPS is the six pin connector for the ECM. You may have to remove the TPS housing from the manifold to see it. Remove it and clean out both the female and male ends of the connectors. Use a dedicated electronic parts cleaner. Reinstall the housing and reconnect the connector. See if this helps. If not, let us know.
 
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