ive got a 96 2500 5.9l gas been having a problems ever since I went trail riding about 8 months ago. I went from getting about 13 mpg to 6 if im lucky. and now its just dumping a lot of fuel on startup and sometimes going down the road, then when I try to stop or take off sometimes it trys to die then idles back up. ive did a tuneup plugs wires cap rotor coil didn't do anything. sounded like I was getting a vaccum leak so I replaced the intake gaskets and when I did that I noticed the coolant temp sensor for the computer im guessing was broke replaced that and now cant plug that in cause if I do truck loads up when tons of fuel has no power and cant go over 50mph.. so im lost guys I need ure help any ideas or suggestions would help

 

Did you fix the plenum gasket as well while you had the intake off?

Did you get the correct sensor for temp? There are two on your truck, a two-wire for the PCM, and a one-wire for the gauge.

Getting any codes?

How many miles on the truck? Do the problems start right away, or only after it has been running for a couple minutes? (from stone cold)

 

yes fixed the plenum gasket.
yes I got the two wire one for the pcm.
the only code its throwing is coolant below temp I forget the code number though.
the truck has 160 but motor and trans only have 60k.
that's the weird thing that I don't understand sometimes it start right away and sometimes it will take like 20 mins

 

i just did the injectors with the upgraded 4 hole ones on Friday and when i did that i plugged the 2 wire temp sensor back in and it ran awesome till i tried to go over 50 then just started to run like **** again.

 

Remove the front O2 sensor from the exhaust, go for a drive. See if its any better. I suspect the cat is getting plugged up.

 

there is no cat it was clogged when I first got the truck so I removed it.

 

Need to get the two wire temp sensor working properly. Otherwise, it will never run right. If it is dumping gas with it plugged in, then the sensor is bad, or, the wrong one.

 

alright ill go tomorrow and grab another one and let u guys know the outcome

 

well replaced it and unplugged the battery when I was doing it to reset the code for the temp sensor.. took it for a drive it ran awesome for about 20 mins then threw a code and started running like crap again. codes r p0171 fuel system lean p0172 fuel system rich.

 

That's weird... PCM needs to make up its mind. Is it rich, or lean.......

Hold old are your O2's? California or federal emissions?