I own a 1998 Dodge Ram 1500 4x4 sport with a 5.9

When I start up the truck, it will idle smoothly for a couple minutes, then spit and sputter and the idle will drop down to 500rpm. The whole truck will shake while it's doing this, then all of a sudden, it smooths out and idles smooth again at about 700rpm.

I've changed the spark plugs, wires, coil, distrbutor, and i've run the wires according the the TSB. I've also changed and cleaned the idle control motor.

Also, if i try to move the truck while it's doing this, it will hesitate and not want to move for a few seconds, then all of a sudden, it will pick up and start going like nothing has happened.

Any ideas?

Thanks.

 

any error codes? CE Light? it might be possible that the O2's have a problem and one of them is shorting out, then opening up when it warms up... cant say for sure but one of your sensors is messed up...

 

Nope, no codes, no check engine light.

Not sure if it matters, but if i drive down to the store or something, get out for five minutes, then come back and start it up, it will do the same thing. Temperature doesn't seem to have an effect, just starting up.

I thought if the O2 sensor was bad, i'd get a code...

 

I have been getting a similar problem. I posted a while ago, but no one had any suggestions. When at an idle, it will "shimmy" then stop and then start again. But I have also been getting a problem when I am driving, it will seem like there is nothing there, no drive, nothing. The RPMs will drop, but then if I give it some more gas or let off, it will come back to me. I thought it was the throtle cable, but I lubed that up. I also noticed that it went away for a while (the shimmy stayed), but since it has gotten wet out it has started back up again.

 

And the check engine light has just came on.

 

It kinda sounds like a fuel delivery problem... Maybe try running some good fuel system cleaner thru it. Maybe your pump is starting to go.

 

depends on the year of your truck... my 2000 will not throw a code for a bad o2 sensor... nice!!!! [sm=badbadbad.gif]

what year is it?

 

I have used a bottle of STP fuel injector cleaner. Is there something else to be used to help the fuel pump?

 

hey it just occured to me... mine is starting to do the same thing. 3 times now it seemed like there was nothing when I hit the gas... threw it in neutral and reved it up and it was fine. I did just replace the o2's, new plugs, and a TPS and this problem started after the swap...

I have a fuel pressure guage in the truck, maybe I'll slap it on there and take a look at the fuel pressure...

 

if your pump is loosing pressure, there is not much you can do to save it... I have heard of the filters clogging and just needing a back flush or something but you have to yank the pump to do it.