I own a 2004 Ram 1500 with a 5.7 liter. On Saturday it started sputtering and stalled while I was at a stop light. It restarted just fine and ran fine for about 15 min. then started sputtering again while I was stopped at a light. I noticed that my speedometer was bouncing between 0 and 10 mph. It countinued to act like this off and on for the past two days. This afternoon it sarted again and my brake warning light and ABS light came on. I noticed that the speedometer only jumps around when the brake pedal is pressed, even if the engine is not running, and that is when the engine begins to sputter as well. The brakes seem to be operating fine, and the engine's performance has not changed. The problem seems to be when the brakes are applied. Has any one had this problem, and if so, how did you fix it?

 

not sure about the problem but it sounds electrical to me.
also please dont take this the wrong way but im a stickler about spelling "just ask my wife" and your saying "breaks" instead of "brakes"
sorry for my bad habit of correcting people!

 

Welcome to the site. So if you go out there and crank the truck and keep your foot off the brake pedal will it run and idle fine? Without putting it in gear and driving it but pressing the brake what happens then?

 

That is correct, the only time the vehicle acts up is when the brakes are applied, it runs normally the rest of the time.

 

try this, disconnect the vacuum line from the brake boost and plug the hose and then try the brakes and see if that changes anything.

 

Thank you for the advice, what do you mean exactly when you say plug the hose? Are you refering to the vacuum line? Where do I plug it into? Or are simply saying disconect the line and reconnect it? Thanks again.

 

There is a vacuum hose that comes off the back of the manifold behind the TB and goes to the nipple on the vacuum booster. Disconnect it at the vacuum booster and plug the hose so there is a vacuum leak to the manifold. Then press the brakes. Now the brakes have no vacuum and thats ok. We just want to see if the vacuum booster is causing issues or if it is electrical somewhere else