Bigyota1989

so i was out about a month ago with the truck and it was running fine when all of a sudden the engine gave me a sputter, ever since then the truck will barely run. it hesitates and dies and will not move unless you put it in four low. funny thing is is this is slightly intermittent. sometimes it will have about 50% power and then act up again. ive done
fuel pump/strainer
fuel filter x2
coil
o2 sensor
plugs,
wires
cap
rotor
mass airflow
ecu
adjusted the valves
it pulled up a code for a bad mass airflow sensor input which what led me to believe it was an ecu or mass airflow sensor. its getting plenty of fuel, the old plugs reaked of fuel when i pulled them out. im going to see if the knock sensor is bad as well. ive built this truck some scratch and can always fix any problems with it in no time but this has me puzzled! and plus i have a mud bog coming up soon and she needs to be running for it! its an 89 22re with a 5speed.

Toyota~Boy

iTrader: (2)

Make sure you don't have a whole or wear spot in the intake tube. That's the plastic tube going from filter box over to intake. If its got the slightest leak it will cause the same problems. Double check timing. You could have sheared the pin on one of timing gears. Check for water in fuel. Also check your fuel pressure regulator. To much fuel will drown plugs. If that don't work check your ignition. Make sure your getting adequate spark to all cylinders. Do a compression check to.

Bigyota1989

compression and timing are mint. BUT i just went there and unplugged the TPS while it was running and it ran great for a little bit...as soon as i went to go plug it back in it started running like crap again..unplug and it clears right up...so i may be on to something

Toyota~Boy

iTrader: (2)

Are all your vacuum lines hooked up correctly. Remove and try cleaning the TPS.

Bigyota1989

yeah theyre all good! but yeah ive never changed the thing so i guess its possible..it doesnt look too easy to take off though but whatever but thanks for the input

Gamefreakgc

Throttle body is very easy to remove, despite all the lines and hoses going to it. Take some pics of it so you remember how to put it back together. It's only four bolts holding it in.

Be sure to put a new gasket on it when done are remove all traces of the old one.

While you have it off, check the TPS per the Factory Service Manual specs (see step 2) with a feeler gauge and multimeter ($15 for both):

http://personal.utulsa.edu/~nathan-b...34throttle.pdf

If it turns out it's bad, meaning it won't adjust to be within spec, use a DENSO TPS since they are the OEM parts. I've had bad experiences with off-brands.

Co_94_PU

iTrader: (-1)

Do not remove and attempt to clean the TPS unless you're prepared to replace it right then. It is a sealed unit, basicly it' a variable resistor and a switch in a box with a spring. The reason I say don't disassemble it unless you have another on hand is due to the wiper fingers they are very tiny and easily damaged. Snag it on a paper towel and it's dead for ever tiny. (There are some pictures floating around here somewhere of the internals)

You can do the FSM tests with it still all mounted and you will know if it is in spec or not.

Your symptoms and TPS unplug indicate maybe the IDL line is shorted out and always grounded. So giving it more throttle registers to send more fuel but it's(ECU) still in idle mode.

Bigyota1989

yeah its definitely a weird issue, its the price of owning a mud truck though, electrical diagnosis is always fun