1995 dodge ram 1500, 4X4, 5.2

Problem;
Truck starts fine, you run the truck to 3 or 5 thousand RPM's no problems, put it in gear and drive it around 100 feet down the road and it start coughing and spitting real bad, won't run at all and if you take your foot off the gas it will die.

I have replace the fuel pump and blew out the line from the fuel rail down to the tank, at the same time i drain and cleaned the tank, no help. Next I replaced OIA sensor, no help. Next I replaced plugs, wire coil, cap and rotor, no help. I have a friend coming over tomorrow and bringing his code reader.

need help, thanks.

 

Does engine temp make a difference? If it does, try disconnecting the O2 sensor, and see if it doesn't run any better.

If that doesn't help, possible crank sensor.

 

I disconnected the o2 sensor no help, but when you drive in reverse it doesn't seem to cough, what the?

 

Does it stall when at lower rpm's? Could be a clogged valve body

 

no it idles fine

 

clogged cat? Take upstream O2 sensor out and see if that helps.

 

When its' cooled off, crawl under it & knock on the cat as you would a front door of a house. Do you hear something loose rattling around? If so, the internals of the cat have come apart. They will sit in place as you idle, but when you move forward they will roll back & clog it & cause poo poo running.

 

Update, came home last night ran it for about 15 mins. no problems. Checked and no codes. I then drove it around last night no problems, ran it up about 70 MPH and it never missed a beat. My son got in it this morning let it warm up pulled out of the driveway and it started coughing and spitting. I did knock on the cat and there is a very slight rattle.

 

Remove the pre-cat O2 sensor, and see if things don't change.

 

Me thinks somebody mentioned that last night...mmmmmm.......