Ok folks here goes. I DO have check engine light on, but AutoZone says they can't read the codes (dumb). What happens is when I first start the truck in the morning, the engine stutters and falters like it has a bad spark plug, these have been replaced. The valve cover gaskets were also replaced, as oil was draining down on top of my spark plugs and causing them to foul out. After a few minutes the rough idle goes away. Then I put truck into gear and it'll stutter like the tranny is going out (my bro has a 99 dodge ram and his did this before rebuild) Then it'll go away and I'm off. Then I'll hit the highway and start to go 50+ mph and the stutter/hesitation comes back! Whole damn engine will be shaking cabin shaking i'm shaking my daughter is like daddy make it stop feels like an earthquake and then it'll level out and stop.... then ride smooth. Then come back when i'm going uphill with the shaking like we're on the set of Dante's Peak. Now I'm curious, would an egr valve cause these issues? Or a clogged catalytic converter? or something with the intake manifold? Or a fuel pump? I have replaced the plugs/ wires/ and distributor. All with no success :( I did notice some of my plugs had light burn marks on them like maybe they were running lean? What confuses me is the rough idle combined with the problem while in gear driving down the street. Could be two different issues maybe, but I'm doubtful because the shaking is the exact same on both occasions. Any advice is greatly appreciated! truck is a 99 4.0L with 220,000 miles and she's my baby I need her running great again!

 

ZERO replies?! what a buncha jerks :p anyway here's what I've got so far. I removed the plug wires and noticed ONE (cylinder #3) part of the distributor was filthy! All other ports looked brand spanking new but this one was covered in filth! So I switch wires #2 and #3 and it ran better, but still gave a stutter going uphill. Now what I've done is spray some cleaner stuff in there and I'm letting it sit tonight will wipe it down tomorrow and let you know if this solves my problem

 

Jerks? Yikes! Don't want to be one of those, so I'll throw my two cents worth in, and you'll find it's worth every penny, if a bit overpriced...

I can't imagine an EGR valve causing all that chaos. There doesn't seem to be much to them except a diaphragm that will cause a lean code when it goes bad. Mine was plugged off for a couple of years and other than a check engine light I didn't notice any difference.

You changed plugs...did you set the gaps? Just checking the basics...I had an intermittent miss under acceleration and it smoothed out when I rechecked and set the gaps.

Did you mention a distributor? I have a 1998 4.0 and it has an ignition coil instead of a distributor. Is that what you meant?

Hope you've got it figured out. I'll revisit if I can help out.

 

You should run seafoam through the vacuum and oil system and see what happens.

 

engine stuuter is mainly a cause of either :

1 / clogged fuel filter
2 / your fuel pump is failing