Possible U Joint Problem & TPS Question

[heavyredchevy]

I have noticed a vibration lately that I can feel in the floor, and even through the seat sometimes. I feel it the most when accelerating from about 40 to 55 then it kind of fades off as I ease off the throttle. Not much time after I noticed that, I also noticed a squeaking noise at low speeds.

One more question. Iv been having troubles with my new throttle positioning sensor. The voltage is too low. If im standing in front of my truck, do I pull it towards me, or push it away to raise the voltage?

Thanks

[67malibu]

What worked well for me on adjusting TPS voltage was to take two thin, short pieces of bare wire, unplug the TPS, then insert them into the plug and replug in the TPS. Attach a voltmeter and you can adjust the voltage just right. Lock it down and get the wires out. It's been a few years so I'm not positive which way increases voltage but I think pulling it toward the front of the truck increases the voltage.

[heavyredchevy]

Whats the voltage for an 89 k1500 350?

[67malibu]

Originally Posted by heavyredchevy

Whats the voltage for an 89 k1500 350?

If I remember correctly (can't lay my hands on anything right now that states it) the factory spec is 0.65 V at the idle position. I'd try that and drive it. See if it hesitates any when you progressively get on it harder and harder from a stand still. I believe I had to compromise on a Holley 670 cfm unit (I think it ended up somewhere under 0.5 V) to not have any hesitation and still get the WOT voltage (~ 5 V.) I don't know about the stock TPS. I never messed with it until I changed the TBIs (I wouldn't recommend it unless you really open up the engine's breathing, a stock 350 doesn't get much from it.)

[heavyredchevy]

Thanks. Ill try this and post back. I first have to drill out the holes a little on the TPS, it turns out It has been replaced before and the new ones dont have holes large enough to adjust.