Newbie Blazer Hesitating

Hi All... I bought a 1990 V-8 Blazer a few months ago. It had been running great. On trips 45 minutes or more the service engine light would come on. If you stopped the vehicle, the light would stay off the remainder of the trip(15 minutes of driving more).

It lately started hesitating around 45-55 mph. When you jump on the gas it would seem to run fine. on level terain it runs fine, On hills it seems to buck. at idle it runs erratically......Any ideas would be greatly appreciated !

Thanks Jim

Jus tbought an 89 myself 5.7 TBI dose the same when it warm. (stop signs and such) runs fin on the road. If you find the cure Please let me Know. Thanks and good luck.

I got lucky...my problem was because of bad gas. I filled half a tank of gas after a tanker truck had just filled a gas station ( major no-no). I use Premium gas. May be your using a lower octane gas then the previous owner ?

Thanks Jim

I have always advocated the use of name brand fuels, for exactly this reason. Though there are any number of people who will tell you that gas is gas, that is not so. Even stations keeping their tanks clean and dry will have variances in fuel quality, depending on the area, anticipated weather conditions, etc. Shopping for fuel will benefit you as much 2 mpg, improved driveability notwithstanding. Ray