hello all, I've got a '92 s-10 blazer 4.3L TBI, 2WD. I've been having a problem with my truck that seems to be getting progressively worse. I start up the truck(with AC on or off), and it will sputter and sputter like its on the verge of stalling out, and it will do this until I rev the engine up to over 2000 rpm. Up until recently, one quick push on the accelerator to send it above 2000 will cause the problem to stop, but lately it takes multiple attempts to get it right. Once the rpm's drop back down and the engine is in its idle, there is absolutely no notion of the engine struggling. Also, I have noticed a pretty big drop in my MPG, used to be I could make it 300 miles on a tank, but now it seems to be more around 270(no changes in my driving, and i usually just fill it up when the gauge lights up). I've asked a few people and the bulck of the suggestions have been vacuum leaks or bad injectors. But I'd think that for either of those to be true the problem would have to be constant, not just before that initial rev. I've tried throttle body cleaner and that dosn't seem to have helped, although I might give it another round. One suggestion which i'm about to attempt is buying gas from another station(I always use the same one) and putting some gunk-out in the tank with it.I'd like to keep this truck running as long as possible as I have plans of rebuilding it once I'm out of school, so any tips for possible solutions would be greatly appreciated.

 

maybe it could be the idle speed or the timing

 

Let's cover the basics first:
1. Have you changed your fuel filter?
2. Have you checked your fuel pressure?
3. Have you pulled any spark plugs to see if they are or aren't wet with fuel?

 

yea im no master mechanic or nothin but is it possible you have some moisture in your tank? are your spark plugs good?
oh and that almost sounds like the trouble i have cold-starting my carbureted truck, does it do it if the engine is warm and does it stop once it warms up? that might be completely irrevelant because it just occured to me that that problem probably would have been present the whole time you had the car but theres no harm in asking right?

 

Try switching gas, but it might be time for a major tune up

 

Well I Think I have made some progress with the Truck. The other night before I gave it half a tank I put in some gumout, and then yesterday I put some new spark plug wires on it(somebody told me that when wires are getting old they tend to do some very strange things). I'm thinking it was the gumout that fixed it but you never know. Thanks for all the advice and hopefully this can help someone else that runs into similar problems.