Severe Hesitation

[heavyredchevy]

1989 Chevy K1500 350 TBI 4x4 Automatic.

Im having some severe hesitation at low speeds/low throttle and i cant figure out what is causing it. it doesnt do it all the time. so far i have changed: Throttle pos. sensor, Map sensor, EGR valve, EGR solenoid, oxygen sensor, idler sensor, plugs, cap, and rotor (tune up), Fuel Filter and fuel line, Cleaned injectors and throttle body. Anyone elese have any ideas? could this be a knock sensor or my computer going bad?

[heavyredchevy]

I might also add that I have replaced the PCV valve, and it idles fine.
The truck has 151,000 miles.
Any ideas at all ???

[steve3320]

Originally Posted by heavyredchevy

I might also add that I have replaced the PCV valve, and it idles fine.
The truck has 151,000 miles.
Any ideas at all ???

Check your cat convertor to see if it's plugged.

[<Xcamarox>]

no idea but if its lacking power and all at low speeds it could be your torque converter like if it sucks below 30 mph and is fine above it

[heavyredchevy]

the cat is new along with the entire exhaust

If its the torque converter would it do it most of the time, but act fine other times?? That sounds like it becuse it only does it below 30 miles or so. I also noticed it not wanting to shift into overdrive untill i have been driving for like 10 - 20 mins.

[<Xcamarox>]

in my opinion its the Torque converter one way clutch. surfing the net a bit cause im bad with wording but i found "If the one-way torque converter clutch slips, then the vehicle will characteristically have very poor acceleration. Mpg will be significantly reduced since engine torque is not being multiplied during acceleration. A vehicle with a slipping one-way torque converter clutch will experience a 20 to 30% decreased fuel economy." which sounds like your problem. from what ive been taught is when that specific clutch goes bad it would be happening all of the time

[heavyredchevy]

Thanks ill have to give that a look. This is getting to the point where my engine is almost shutting off, like it was starving for fuel... ill have to give my fuel pump and fuel pressure a look at to. this is just kind of strange that there isnt any codes.

[mbumgua]

If not torque converter--check fuel pump pressure 9--13 lbs

[heavyredchevy]

Originally Posted by mbumgua

If not torque converter--check fuel pump pressure 9--13 lbs

Can i rent a pressure tester? They are not really that cheap, or is there some other way of testing it?

Thanks