Hi, new here but don't let that fool you.

I went to tech school for 2 years and have an associates degree in Automotive Technology.

But I'm having problems with my dads dodge ram that I can't quite figure out.

2001 Dodge Ram 1500 1/2 ton pickup 5.2 L V8 with A/C

My problem is that when under load when pulling a small trailer or boat on the highway. The engine RPM will jump around 300-500 RPM when the truck hits a bump. It sometimes does it without hitting a bump or dip, but mostly does it when it hits bumps.

I can clean the throttle assembly with a brush and throttle cleaner and then it will run fine for 20 or 30 miles. I did replace the MAP sensor because that wasn't working properly. The TPS senso has 5 volts going to it. has 1.5 volts closed and 3.7 volts fully opened and the voltage increases as I open the throttle, so the TPS senso tests good.

My concern was the IAC sensor. It tests good and the pintle moves smoothly. I took the IAC sensor out and cleaned all the carbon out of the hole and off the pintle.

Do you think my IAC sensor could have intermitent problems?

I did fix the transmission about a year and a half ago. the bolt that was the adjustment for the 2nd band worked its way loose and the truck had no second gear, but this doesn't seem like a transmission problem.

Any help would be greatly appreciated.

Dave

 

The IAC sensor can cause intermitent problems.

If you leave the sensor out and work the key you can watch it move. It sounds like you've done that, but how many times did you check for movement?

I've seen some where you can do that 25 times in a row, and 10 of those 25 times it won't move at all.