i have a 1999 chevy blazer. it was running like it needed a tune up so i put new plugs, wires, cap , and rotor in it. It does run better but when you frst start it and take off it spits and sputters pretty bad. but comes out of it and runs good in about a block. also i dont the gas mileage is up to par. i also put a knew intake air temp sensor in it. and i think i can here a slight spark knock when i accelerate. i am going to try puting a new coolant temp sensor in tonight, but i am open to further advise. its a 1999 s10 blazer 4.3L v6 auto 4wd
Thanks, Mike

 

why did you replace the intske air temp sensor?

do you have a check engine light on?/ checked for codes?

look at wire harness connections for loose terminal plugs /chaffed or pinched wires or hoses where you were working, its pretty tight back there.

check the work you just did with the tune up make sure one or more of the boots is not loose on the dist cap or on one of the plugs and the firing order of course.

its a place to start hope it helps

 

I change the temp sensor because i read that some of the symptoms of a bad temp sensor was, extended crank time when the engine is cold, poor fuel economy, and spark knock. Pretty cheap part so i tried it. same with the coolant temp sensor, havent tried it yet though. also no lights on the dash and no pending codes. ill look it all over again tonight when i get of work.
Thanks, Mike

 

i have the same probs, mine started ticking awhile back, then after I changed the spider injector ($350) and the cam position sensor, it quite ticking and ran like a champ for a whole day, then back to the same ole same ole. the only code im getting is the cam/crankshaft position sensor. I'ts a 99 4.3 auto 4x4 as well, SOMEBODY PLEASE HELP US!!! I'm completely confused . oh yea I put cap rotor plugs and wires on it too, no change. Changed the spider cuz it would only start on ether, and that fixed that problem.

 

What is the specific code and what diagnostic steps have you performed to try to narrow down the source of the problem? Replacing parts can become an expensive endeavor if you aren't actually determining if they are at fault prior to replacement. You can find quite a few of the OBD2 codes listed in the index link found in my signature below.

 

I had the same problems and cleaning the MAF sensor took care of them.
See my post "Can't get and/or won't take gas," and read my last thread entry.
Mudcat