So ive got a 99 ls 2dr 4x4, i purchased the truck a few months back. I was told the 4 wheel drive didnt work but i never tryed to engage it. Winters coming pretty quick and im considering trying to fix it. Its not throwing any codes.

Also had a few other questions on the vehicle.

After my truck has ran for a while when i stop at lights with the it in drive the rpm's seem to periodicly raise and then drop, with it in park it does not do it.

When i turn the car in and listen near the rear drivers side tire i can hear hissing, again not throwing any codes.

Also wondering if they make fender flares specific to my blazer, and what size tire i could stuff under it with minimal to no rubbing.

 

https://blazerforum.com/forum/tech-a...ill-help-7180/
post # 5 really good info

for rpm at stop light, have you done a tune up? Delco plugs?

I think the tires can't really go much bigger without a lift or spacers

 

A/C compressor turning on and off can make the idle fluctuate a little.

Is it a hiss you are hearing, or the faint whine of the fuel pump? The fuel tank is right where you're listening. Vacuum leak perhaps?

 

I havent done a tune up yet i plan on doing wires plugs and fluids very soon.

The top far right pully has like a disc on te end and sometimes itll all spin and then others jus the pully and not the plate.


And it is a hiss

 

make sure to do cap and rotor with the tune up, and pcv valve doesn't hurt...and fuel filter since were talking driveablity

that disc is the A\C compressor kicking in and out

 

sounds like a vacuum leak