Pontiac Repair: 2001 Pontiac montana, chevron techron, pontiac montana

Question
While driving my van I have noticed that the RPM will fluctuate. I notice the tach bounce up and down between 1500-1800 RPM and jerking of the vehicle. Usually occurs between 25-40Mph.I step on the gas or brake, the problem goes away. The problem is intermittent so I'm guessing that it has something to do with electrical.Outside of this range, everything seems to run normal. The van will accelerate normal and doesn't have any stalling issues, so I find it odd that the problems only occur between 1500-1800 RPM. Any ideas?

Answer
Hey chris:

any service engine soon lamp on? it doesn't misfire at all buck/hesitate? How many Miles on this Van. Has it been kept up as far as maintence? When was the last time the fuel filter was replaced? Have the injectors ever been cleaned? You can try a product called Chevron techron and add that to the tank that helps some times. This can be an ignition system issue or a trasnmission issue. Does it do it if you hold your foot stead on the gas and just tap the brake pedal? If so it may be a torque converter cluth issue inside the transmission How does the fluid look in it? Is it full? if the problem was bad enough it should trip on the servce engine lamp and seat a code(S) if not the issue is not bad enough yet. You can take to any of the big box auto parts stores and have then scan for engine/transmission codes most of them do it for free. see if there are any codes stored and then go from there..