Ok I have a 95 rodeo 3.2L 4x4. Just bought it. Ran good when bought. The other day was goin down the road and it started running like crap. won't really go above 4000 rpm and then it sounds like the air intake is backfiring or something. Will not go above 4000 RPM. It is really hard to start when cold. Sometimes it backfires after being cranked. But after numerous tries (about 50) it finally starts. Still runs like crap though.
I have changed the following:

plugs
wires
coil packs
EGR valve
MAP sensor
CKP sensor (crank position sensor)
have taken off catalytic converter and it isnt clogged at all
changed oil and filter

the truck blows out white smoke when first started and then diminishes away, but it did that before this all started happening. I believe it is the valve seals leaking while parked. No CEL! (the CEL works because it illuminates when key is turned) I am so stumped here. Anyone have any ideas? Could the ECM be bad? Or the IAC or TPS?

 

timing belt might have jumped a tooth

 

its very easy to check just pull off harmonic balancer and timing covers and the crank notch should be at a 90 degree angle and the top lines should match up with corresponding notches on camshaft.

 

these motors are non interference motors so it will literally run till it cant and not hurt anything

 

o i thought it was interference engine. well that makes me feel a hell of a lot better about timing belt breaking and all hell breaking loose.
the timing belt has been changed recently and i checked the tension and its tight. So i dont believe it jumped a tooth. Could fouled plugs make it run this way? or the tps?

Im going to check the timing anyways just to make sure. been trying to get around that because i live in an apartment complex and it sucks to work on cars here.

 

yea fouled plugs COULD but i doubt it, a hint on plugs though try to stay with oem none of that bosch triple platinum garbage.... just get what the auto retail store says is oem ive fixed a few cars by just putting original plugs back in. as far as the tps possibly but i dont think so.. have you tried maybe the fuel filter?

 

yea i think tomorrow i am just going to take off the throttle body and then the plugs and clean both really good and see if that works. if not ill try the timing. havent tried fuel filter yet. probably should lol. how do u relieve the pressure off the system?
the plugs that are installed are autolite i believe. yea bosch plugs suck.

 

there is a little valve on the top right of throttle body where the fuel rail is just press it down.

 

how did everything work out for you on this?

 

Jumped timing. Runs beautiful now that I changed the belt and tensioner