The title pretty much sums up my issue. I just picked this truck up a couple of weeks ago, so I have no real idea about its history. Whenever I am giving it gas, the truck runs great. And it runs great at idle. But when I let off the accelerator, it bogs down and sounds like it wants to die for just a couple of seconds, then it comes right up to idle fine.

 

'88 is when GM was going with fuel injection across the board. Is yours fuel injected? Clean your throttle plate. Gooky stuff (<-------fancy technical term) keeps enough air from getting past when it drops to idle. Be sure to use spray fuel injection cleaner and NOT carburetor cleaner. It can ruin your TPS.

 

Yes, my truck has the throttle body fuel injection. I'll try cleaning it out with some injector cleaner and report back.

 

take off the idle air control. It looks like a lil can that screws into the side of the throttle body. you'll see a lil piston lookin thing when u pull it. spray it down with some brake cleaner,and the inside where it goes and scrub it out with a toothbrush. these things rarely go bad,they just get sticky and dirty. they maintain your idle.

 

FYI, 87 was the first year for TBI in the Blazer.

 

My first S-10 was an '86 I bought new. Decent truck until I got pushed a half block by a big car with bad brakes. The insurance company fixed it, along with the car I bounced off of and the van the guy who hit me, hit next, but it wasn't ever right after that. It had F.I., along with the next S-10 I bought. A 1988 that was the biggest piece of garbage I've ever driven. 14 dealer trips the first year I had it. I crushed better trucks than it when I had a salvage yard.

 

Tried cleaning the throttle plate but that didn't seem to help. Looks like the previous owner had tried that. The plate looked really clean. I'll try the idle air control next.

 

Report back about the IAC cleaning and let us know if it fixed your problem.