94 150 351 5.8L AT. Just cured a harsh violent shake of truck with new u-joints, engine and trans. mount. Continued with what others have called a shudder w/ $ to have the torque converter changed and trans job I am trying to rule out the many problems that I seem to have right now. I appear to have a jerking hesitation in acceleration as if not getting gas. It happens after warm up. Truck idles in P & N fine. Tried the slow increase in RPM in park but no missing or change still smooth. I changed spark plugs and wires. Routing as suggested in threads to avoid arching with careful placement. (Ex/ 5 & 6 seperated). I drove it 6 miles tonight and noticed the jerking is getting worse. This only happens on gasing once released no jerking at all. Besides the shudder and this jerking miss upon acceleration I seem to have a delayed shifting which happens from time to time between 2nd & 3rd gear. It definetly is shifting hard like those described in threads with "Slamming" as the desrptive words. I have read about TPS, MLPS, Torque Converter, EGR, Fuel Pressure, Codes etc. Just need some priority direction. It seem the codes appear to be the start. Could use your guys advice. Getting rid of the truck advice has already been stored but out of the question.

 

I would add some fuel injector cleaner to the gas tank. This cured my 88 F150 with the 4.9l engine of severe bucking. Also change the fuel filter if you haven't done so recently.

 

Just checked my new wires and they are defective as I found 4 arching areas and also at the coil. Do you think this would cause my engine struggling with the jerking only upon acceleration? Would this not affect the idle all the time and not only when I am pressing on the gas?

 

TPS blah blah message to short. Throttle positioning sensor.

 

On the E40D, the computer checks the VSS sensor against engine RPM. It knows what the gear ratio is. If it detects too much of a discrepancy between input shaft speed and output shaft speed (from a worn torque converter or bad gear change clutches) it assumes the transmission is slipping. In an effort to protect the transmission, it will enter "performance mode". In performance mode, the computer boosts transmission line pressure by changing the EPC solenoid duty cycle, and tends to delay shifts to a higher RPM/vehicle speed.

The end result can be felt as "slamming" or "hard shifts". The computer should eventually set code 628 or maybe code 648 in continuous memory if it chooses to do this. Run a KOEO test and see if it has. Other causes of "performance mode" are issues with the MLPS (computer isn't sure what gear is selected), or a bad VSS (computer does not believe the vehicle speed input).

If there is any arcing around the ignition wires, I would fix that first. Then I would pull codes to see if there were complaints registered from the computer. Then I might try a trans fluid and filter change to see if I could cure the shuddering. Maybe dump in some anti-shudder additive or use the special anti-shudder fluids. If you can cure any major torque converter slippage you will probably cure the hard shifts.

 

Change the wires (I'm sure you've already done this) and check coil. Go with the filter/fluid change and make sure to examine the trans pan when off for any foreign material, metal, etc. Change the fuel filter. Make SURE to bleed fuel injection system when changing filter.
Tex

 

Thanks al will get to work. Appreciate your knowledge.