I'll try to explain this as best I can. I'm not a mechanic, and this problem is not real consistent.

Basically, it goes like this. Since sometime in February, for no reason, while driving down the road, the engine seems to surge. As in, the RPMs climb 200-500 for a brief second, then drop back off. I drive my truck back and forth to work mostly. The trip consists of a 5-7 mile distance at 35 to 40 mph to the interstate, then another 10 miles at 65-70 mph, then reverse at the end of the day to go back home.

It usually does it after cruising at a steady speed for a few minutes, usually going down the interstate with tach reading 2000-2300 RPMs. Does it a at slower speeds too, but never when the tach was below 2000 RPMs or below 40 mph. It can happen two or three days in a row, then not happen again for a week. It can surge three or four times in a row, or just once. It can do it with the engine still cold, or after driven for a while. I have never been able to duplicate it, I drive the same route 5 days a week and I have never able to make it happen.

There has never been a code, or check engine light. I’ve had it to two different shops. Neither one could duplicate it, or come up with anything wrong at all.

It does it both with cruise control on and off. Does it when the outside temp is cold, it does it when it is hot. It has never surged more than 500 RPMs, and always drops right back off.

I’ve got a 2001 Quad cab SLT with the 4.7, with approximately 85,000 miles. No modifications to the truck, other than a Flowmaster dual exhaust installed in 2002. I regularly change my oil, change the air filter twice a year, and give it some injector cleaner now and then.

Any ideas??? Sounds screwed up I know, it annoys the crap out of me. Thanks.

 

Hmm... IIRC, I read a few people had this problem and it turned out to be a throttle position sensor (TPS).
You can download a service manual for your truck via a link given in this post (thanks to Daksport1pa).
The TPS is mounted on the throttle body, and is a 3-wire connector.
It gets 5 volts from the PCM, and, in turn, sends out from .26 volts (idle) to 4.49 volts (wide open throttle, WOT) to the PCM to represent throttle position. It is provided a ground path via the PCM.
The 5-volt feed to the TPS is the Orange wire. The sensor ground is the black/light blue wire. The input to the PCM (and Transmission Control Module for 4.7L with automatics) is the orange/dark blue (center) wire.
Check the 5-volt feed to make sure the TPS is getting all 5-volts. Than check the output voltage, and make sure the transition from idle to WOT is smooth. Also make sure WOT to idle is smooth.
Also check for resistance (ohms) from the TPS ground wire to the PCM; as well as from the TPS output wire to the PCM. (You will need to download the manual to find the proper pins.) Resistance should be very low.

 

totally agree. the TPS sensor is a potentiometer and when you do a resistance test you need to make sure that the resistance is steadily moving up or down and that there are no jumps or dead spots in its band. its much more likely that you have jumps or dead spots in a potetiometer then it showing a resistance that is out of spec. carefully go through the entire range of motion 2-3 times to verify its good.