I have a dodge that I've been having problems with. When cruising on the highway holding a constant speed the truck will start bucking or shuddering. To come out of it I can either release or depress the gas. This seems to typically happen when the truck has no real load on the engine. I can tow with the truck and it does good, probably because the throttle is always moving - although I have had it start bucking while towing. I have trouble code 32 and 37, 32 is due to removing the egr valve because I am to cheap to buy a new one. Don't know what the 37 is though - help please

 

search for plenum gasket leak test

 

How would that make the truck jump and shudder, I am having a similar problem. No CEL though.

 

Could be your MAP or TPS.

 

checked the TPS voltage it was good, checked the MAP it was good, I didn't see any oil nor am I losing any oil to the plenum gasket - I will search for the test procedures. I am going to try new cap rotor and wires - they have warranty. any other idea?

 

Unbalenced tires or bent wheels can do this to, also is you have ever used fix-a-flat or ties jack.

 

Broken plug wire or a cracked coil will do this,.. In-fact a crack in the porcilin on
a plug will also cause it. Bad rotor or cap too.

 

I am going to try the cap and rotor, I went to check the cap to ensure that everything was tight and I got the Sh$t shocked out of me. Probably have a bad wire or cap... I'll let you know how it turned out.

As for the fix-a-flat or bent wheel - this is more of a jerking action vs. a shudder or vibration. don't use fix-a-flat my tire guy would hate me for it.

 

I am having the same problem but mine gets worse when the AC is on. I also have had the engine stall. It will start right back up and the engine seems to have plenty of power any ideas?

 

When you checked your TPS did you use a digital voltmeter? If so, try again with an analog meter so you can catch the needle twitching if you hit a dirty spot.