tps going bad?

[blazerboy]

I just returned home from a 500 mile round trip vacation and when I pulled into town my tranny started acting up,when I stopped at the first stop-light it didn't want to downshift until I was completely stopped.Then when I take off it shifts through all of the gears into overdrive before I reach 30 mph,if I push down on the pedal it won't downshift but blows out black smoke and no power,if I manually downshift then it spits and spudders and acts like the timing is way out of whack.Any ideas would be great,My truck is a '94 chevy light duty 3/4 ton 4x4 with a 4L80E. I just changed oil and filter which was clean and not burnt with only minor shavings on the magnet,
thanks, Kyle

[Robyn]

Is the check engine light coming on???

Pull up the codes and see if anything is showing.

With this much issues there may well be something.

Another issue can be voltage to the system.

The 94 charges the left battery and the cross over cable supplies power to the Right one. Using a volt meter, check the voltage at the RH battery.

This needs to be 14V with the engine running.

Be sure all the cables are clean and the gounds at the engine are good.

Check the two engine grounds at the RH rear of the intake manifold.

These grounds come from the main wiring harness at the firewall and are close to the tranny dipstick.

If the alternator has decided to leave this world and the charge is low, this can cause all sorts of wierd stuff as can poor grounds.

An issue with the PPS (throttle pedal) will usually set a code and turn on the ses light or the service throttle light.



Let us know what you find.

Best

Robyn

[blazerboy]

No engine light coming on,
code # 69 comes up which on my code reader says it is the air cond. but online it says the tcc or torque converter clutch may be mechanically stuck on.
my rh battery is at 12.57 (engine off) and 14.10 (running)
my lh battery is at 12.58 (off) and14.18 (running).

[blazerboy]

The tps was fine,
the tcc solenoid was stuck on (previous owner ran a toggle switch to operate the lock up converter manually)and the power wire was spliced into the keyless entry power wire which came unplugged.