z71 acting very strange ? ?

[liftedexpectations]

so i had to drive over to new orleans for work and b4 i did i have only drivin the truck around town and on a rare occasion on the interstate for very short distances . the truck ran fine it seemed but on my way back to mobile i noticed the rpm gauge would surge between 2300rpm to 2600rpm on a flat stretch with no hills at around 75 mph . when i got back to mobile i took it to advanced to a diagnostic scan on it and it pulled up my maf and a multiple miss fire ? the guy at advanced said to check my maf fuse and do a full tune up . but i told him about the rpms surging like they did and he had no clue what it could be ? ? so does anybody have any ideas at what this could be ? and what is a normal rpm for a 96 z to be running at 75mph ? 2500 (average) is what mine seems to be running and that seems to be awful high to me . the truck is a 96 z71 with a 4l60e btw in case that info was needed for help .

 

[454/4X4]

At 75mph, my 94 Z, with same trans, 3.42 gears, and 33" tires, turns about 2250 as I recall, give or take...I rarely go on I-10...

With 3.73 gears, which were available...2400 or so would be normal. Almost sounds like your Torque convertor clutch was locking and unlocking.

 

[liftedexpectations]

so do i need a new torque converter ? i know the trans was replaced not to long ago . so where should i start ?

 

[454/4X4]

It greatly depends on what the problem actually is, the surging could be the engine, or trans, could be a sensor, solenoid, wire...but Id take it to a shop and have them scan it, like...drive it, and scan it...they can watch the various sensors in real time, and see what the trans is doing as well...parts are spendy, and it sucks when you start guessing on a a hunch.

 

[liftedexpectations]

thats a good point .
thats probably what i will do . a buddy of mine owns a shop so ill call him tomorrow and see what he can figure out for me . thanks guys