My grandson recently acquired a '94 Blazer with a 350, automatic and air. The tires are slightly larger than stock. Milage is about 140K. The acceleration onto the interstate is less than impressive. We have checked spark plugs, ran cleaner through the fuel system, and put on a new air cleaner. It is still a dog above 4000 rpm. It shifts at 4250, but takes forever to get there with the throttle wide open. Also has a new throttle position sensor. Is there something we are missing, or are we just expecting too much out of the smog era heads and TBI?

 

Was the 350 swapped in by a previous owner?
With a 350, if it really has one, it should be doing pretty good. Mine with the stock v6 (CPI) has no problem getting up to speed on the highway.

 

Is this a full size?

 

Ahhh... good question. I keep forgetting there are full size blazers... hahah!

 

This is the full size Blazer (at least as big as they made that year) looks like a 2-door Tahoe.

 

It should still do pretty good with a 5.7. You should run a copression test on all cylindders and make sure they are above 110psi at least. Is there any engine light codes store on it? The "paper clip method" is an easy way to read them if there is an engine light on... Then come back and post the codes here.

 

Compression test is next on my list. I thought it should do better too! I think the heads and the TBI are crippling it. I will take it to the parts store and check for stored codes. No check engine light at the moment.