RPMs fluctuate at highway speeds?

[dsmile1968]

I have a 1994 2500 turbo cummins diesel. I put it in a Dodge dealership shop they couldn't fine anything wrong with transmission. but said I needed some maintenace done that would probably fix problem they adjusted injector pump timing to max, valve adjustment , replaced fuel filter but I still have problem. I called service advisor to tell him that I still have the same problem he said that it didn't have any codes but to bring it back in and let them check it out. At $350.00 less and still have same problem I dont think so . If anyone can offer any help please reply. Thanks

[tkelly]

do you actually feel the change in rpm or can you only see it in the tach. i have heard of induction on the tps (i think its the tps) from the alternator that causes all kinds of grief. check grounds and look into shielding of the harness. at work and dont have time to go back and get the full details.

[flea]

Read this thread at Pavementsuck.com..... it may help.

http://www.pavementsucks.com/forums/viewtopic.php?topic=41741&forum=11

Flea