2002 Ram 1500 4.7 Hard Start rough idle accerlate hesitation
 

Ok folks, I am sure you can help me out here. Truck has 185,000 miles on it. I have had it about a year and this problem started shortly after I bought it. I have lived with it this long, but I am tired of the problem. Here is what's going on:


When cold, it take cranks 4-5 seconds before it starts. Sometimes after it does fire, it hesitates a little before the engine gets up to idle rpm's.


When idling parked, or at a stop, sometimes the rpm will fall for a few seconds then jump back up all by itself.


Other times, it will fall, then die when idling.


From a stop, when accelerating, it will "pulse" and hesitate for a while.... Not every though. I have never had any issues when traveling down the interstate. It likes to do this in town in stop and go situations.


There are NO CODES and NO ENGINE LIGHTS ON


When I search this problem, I see it could be every and any sensor, fuel pressure, fuel pump, etc


I have already run injector cleaner through the tank a few different times. I really don't want to start changing sensors, but I am going to change the fuel pump. I figure start here because I THINK it is the most likely issue.


The biggest problem is no check engine lights and no codes.


Has anyone run in to this and if so, what did it take to make it right?


Thank you for your input.

I would clean the IAC you can remove from throttle body and get some IAC cleaner and clean or get a new one. I know a carbon gummed up one will make the Idle erratic.

Idle Air Control

good luck

How about plugs/wires?


SJ03

Sounds to me like a bad TPS. I had a vehicle with similar issues, and the TPS was off spec by a whopping 0.2 Volts. That made all the difference in the world to the PCM though. They are pretty easy to test with a multimeter, and easy to replace. Test your sensors instead of just replacing them. Check youtube if you don't know how to do it. Best of luck!

BINGO!!! IAC valve. I cleaned the throttle body, which wasn't too bad. Iac was really gummed up. Put in a new one....no issues now. Thanks