Change out the MAP sensor.

 

Also you might want to fully clean your Throttle Body. While you have the TB of check the belly pan gasket in the intake manifold with a flash light and check for oil inside.

 

Well guys I took the throttle body off this afternoon and cleaned it. I looked at the belly pan gasket and there was no oil laying in it actually real clean. The truck does not use any oil I change it every 3000 - 4000 miles and it does not use any inbetween. I took it for a test drive and no luck like riding a bucking bronco only does it on acceleration or pulling a hill the tach does not move when it surges once you get up to speed and set the cruise no surging at alll but you can slow down to 40-45 and slowly accelerate and it surges. Thanks again guys. Dave

 

Sounds like a MAP sensor.

 

any news? i had this happen on my 99 SLT 4x4, and i ended up being a bad fuel filter, once that was changed it was like it was a new truck

 

Check the fuel pressure to make sure you have adequate pressure to the injectors. It may not hurt to have your injectors cleaned too.

 

I posted about Christy's problem not starting. I also have the surge problem and have heard this could also be related to the PCM which I have problems. If you have starting or idling problems check the PCM, but if it was just the fuel filter let me know Thanks.

 

Here is a cut and paste on reseting the PCM. Doesn't cost a thing to reset, but may rule out the cheaper fixes.
I have had various symptoms on my 99. I would reset my PCM and that works for about a month. The first time D wouldn't stay idle. Second Third and Fourth time D wouldn't start. Also while under steady throttle it would sputter as if fuel starved. I checked on another forum and this is a common problem with the older D's. To reset your PCM disconnect your battery and wait, not sure how long I usually wait about an hour, then reconnect your battery and be ready for the alarm to sound as the first time I tried this I put my head through the hood. Then turn on all of your accessories such as lights, A/C on high, radio, fog lights etc., start your SUV and let idle until it has reached operating temperature, then turn off the SUV and restart.That should reset the PCM. It is not a permanent fix as I have stated, but a PCM is expensive and hard to find. My cheap butt is still shopping around.

 

I contacted ECU Direct and of course you check connections, wires, etc., but they had mentioned scanning the ECM which would determine if the problem is PCM or wiring. They also stated that the scan could tell if the PCM is reprogrammable. If the PCM is reprogrammable the cost is $300 plus shipping, if not reprogrammable you can buy areprogrammed one for $395. A new PCM will cost around $600. ECU Direct says the give a lifetime warranty! I have not dealt with them though they do look legit. I have checked other parts places with no luck finding anythingother than Kragen who can order a reprogrammed PCM for $350, but no warranty.

 

If the PCM has issues, I doubt reprogramming it will do any good if hardware components within the PCM is going out. Otherwise, go buy a Hypertech III programmer for the 5.9 and then reap in the extra power and possibly fuel mileage.