98 Blazer Erratic Tachometer???? NEED ANSWER

[Wildman98]

Since Feb 04 when I bought my blazer I have managed to sink just over $1000 into it in steering/suspention parts, overheating, alternator and 4wd/tranny problems! I cannot seem to figure out why my tach needle jumps all around.

I am driveing normal down the road and the tach needle will suddenly spike or bounce around for a second then seddle back down where it belongs. It dosent matter the weather conditions or anything. While under a harder acceleration it will actually go from reading 3000rpm to bounding around very fast at the 5 and 6k marks erraticly and sometimes u can actually feel the truck hessitate with the way the needle is jumping and seem not to shift correctly/slip a little with the needle....I am lost, any help would be great!

[Rbraczyk]

Does the motor react with the tach? Or does it go seperate? It may just be an issue with the gauge if it goes seperate.

[Wildman98]

9 times outta 10 the engine will react with the needle jumping. you will feel a little hesitation/skip when it does it, especially under a harder acceleration

[Rbraczyk]

No SES? It may be a sticky throttle or something wrong with the throttle in general. Wish i had a pair of diagnostic dice.

[Wildman98]

The ses light has never been on