This might be a long post, but I have categorized everything:
Problem: Erratic Shifting after replacing E4OD. Unclear-able code 629

Replaced: MLPS and connector ; replaced torque convertor twice ; replaced solenoid pack twice ;

Repaired: vac line from purge valve to cannister ;

Tested: TPS within spec ; pulled harness out and tested all wire from trans. to PCM no problem found. tested MLPS ohmed out within spec.

New information: Drove truck today with AC on. Shift 1 to 2 smooth, 2 to 3 smooth BUT 3 FELT LIKE 3-4 WITH O/D OFF. pressed O/D on and shifted to O/D. ALSO during normal acceleration the Air from the Vents switched to the defrost vents !!! Then switched back to vents when cruising down the road (not cruise control). Does this everytime from stop.

Old info: still slams in R and D from P and N respectively, still will not move forward unless move selector to 2 then back to D.

There are no respectable shops within 75 miles of my house so I dont have access to a break out box which they want 700+ for.

Anybody have any ideas? Thanks for all your help so far. But I'm running out of money but now I cant afford to not fix this truck and buy a new one. Plus that would be like giving up right?

 

On the AC issue, check the white vacuum line in the main passenger side corner of the engine bay, on top of the heater core box.

It's probably cracked... Replace with some rubber vacuum hose and all should be fine in that dept.

 

You have a vacuum leak. If above post doesn't help it could be in the A/C unit it self.

Craig

 

Good Eye SideWinder4.9l that fixed the vacuum leak! Took all of 10 min.

Here is the newest find: If I Accelerate from a stop at a rate that keeps the RPMs around 1500 to 1800 the transmission shifts like a brand new trans. No 2 shift 3rd and even shifts into O/D at 55 mph. Any Ideas? Anything above that RPM and the L to 2 shift is long and a bit harsh and the 2 to 3-4 type shift is back with or without O/D on. I still have never had the O/D light flash ever. Clueless

 

I'm curious on something. It isn't exactly transmission related; Yet it is.

On the shift indicator, is it floppy/loose? When you go from P to say D, does the indicator actually stop at 2, or 1?


If it does, it's needing to be adjusted. 2 little wheels do the trick. 1 is on the steering column, and the other is directly below the PRND area on the cluster.

 

No slop in the gear indicator at all. I tried a little test today. I put the trans in N climbed underneath and loosen MLPS 8mm bolts and turn the MLPS all the way clockwise. Tightened it down to spec and went for a drive. The only thing that changed is that the reverse lights did not come on. Absolutely Nothing Else Changed. What does that mean? When I get home I am going to try it counterclockwise. If no change again what does that mean?

 

UPDATE: MORE TESTING

ReTested TPS throttle valve closed 3.2k ohms WOT 352 ohms Back probe ground and signal wire KOEO .95v at idle 4.95v at WOT VREF 4.95 from PCM to TPS.
Tested BPA-ISC 10,5v from PCM and 11 ohms resistance harness unplugged.
removed and cleaned minimal carbon (almost new looking) Changed o-ring and reinstalled.

The reason I tested these is because I notice that there is no change in idle from drive gear to park. It should rise in P like any other vehicle right?

Still cant figure out why trans shifts normal if rpms stay below 2000 through shift pattern. Anyone ? Thanks for any input, Im getting to know my truck up close and personal.

 

CANT SLEEP GOING INTO THE PCM TO CHECK FOR BLOWN CAPACITORS AND COLD SOLDER JOINTS MY LAST RESORT UNLESS SOMEONE KNOWS SOMETHING I HAVENT TRIED BESIDES A BREAK OUT BOX.