I have a 1990 Dodge Ram with the 5.2L/3-sp auto. A while back it developed a miss, only at idle. If you're sitting at a stoplight with your foot on the brake and in drive, it lopes. It also stinks like its running rich suring this mess. It's bad enough that it shakes the whole truck like its got a competition cam in it or something. Once you hit the gas, it disappears and runs fine. No smoke or anything. It has 202,000 miles on it and has never had any work done to it other than regular maintenance. I bought the truck brand new and have never modified anything. I have already changed the plugs, wires, button, and cap. Could it be a timing problem? Vaccuum problem? Coil? ANy help would be GREATLY appreciated.

 

It sounds like a timing problem, your computer automatically advances your truck when you accelerats, so it could be bringing your timing down so far at idle that it is causing it to misfire. I dont know how to fix it other than getting a new computer, or bypassing the computer with an msd, but that is what it could be. Have you tried replacing the coil? I doubt that is it, but coils are cheap any way. Other than that, timing sounds like the problem.

 

The timing chain's never been replaced. Since there's a little bit of a leak around the cover I could just go ahead and change it out. What about this MSD? Would that actually bypass the ECM advance? Thanks!

 

The MSD controller goes straight to the distributer, it totaly bypasses the computer, you have to splice it into the wires that are already there, and the ones that go to the computer you can completly remove, if you bought the kit, you would see what i am talking about, they have a full instruction manual and a wiring diagram.