backfire through intake

'97 2.2L
this has been a problem since i bought the truck...
when i gun it in neutral it backfires through the intake, then studders through the first 750-1000 rpms and then is fine. this also happens if i'm in too high of a gear, but i don't let that happen. it's getting better (after new plugs, wires, o2 sensors, fuel filters), but i still have the problem. i've now been told by a mechanic friend to replace the ignition module. i would like input from someone who has done this on a s-10. i'm wondering if i should get an upgraded setup and if so, opinions on what brand/model.

check the distributor cap and rotor. i've seen them cause a ton of problems on blazers. the egr might be hanging up a little too.

it's distributorless which is newfangled/foriegn to me

First off, do a full tune up (plugs, wires, etc). If it still does this then start on things like the ignition mod.

"it's getting better (after new plugs, wires, o2 sensors, fuel filters)"
He already did.

I am sorry, didn't see it. Please forgive me.

I had the same problem on my 95 4.3. Backfiring under higher load, low engine speed situations. I knew (thought) the tune up wasn't that old, so I kept fecking with other stuff. Finally I grabbed ahold of each ignition wire at the cap and BAM, there it is! New wires (did the cap and rotor first and that didn't help) fixed it right up. I know you replaced those already, but I'd still focus on the ignition for this problem. Good luck.

it turns out it wasn't spark. i bought new plugs, wires, pcv, egr gasket, and priced new ignition module about $160. i installed new pcv and cleaned the egr and half of my concerns are gone. no more backfires or stuttering through low rpms. i don't know if it was the pcv or egr or both, but that egr was crusted shut. i will keep my plugs and wires for later seeing as mine are only a few months old. this should have been obvious i think, but i've never owned a vehicle with an egr, or i never new it was there.

Might be time to take a look at mine, before a problem starts. 105k on it now. Thanks for the update.

you'll probably get some mpg back at least

Maybe this is my problem too. Please someone help... I was driving on the freeway at about 55mph and without any warning at all, the truck just died. RPMs hit zero, no throttle. Just like I was sitting still only trying like hell to make it passed the Los Angeles rush hour traffic. The truck will crank and backfire through the throttle body but thats it. I towed it home and tried a process of elimination. After calling a few shops and a few auto parts places to get info, I started with Ignition. I changed the Pick-up coil, the ignition coil, the control module and the crankshaft adjustment sensor. I also tried fuel down the throat. Nothing seems to be working at this point.

Please help...

what kind of blazer?

yesterday at a stoplight my cat decided to take a crap. don't know if working egr contributed to this, but it sounds like s...

97 S10 Blazer 4.3L

It turned out to be just the Cap & Rotor. I started the process of elimination with the expensive parts first. Maybe you should try it the other way around. Try a tune-up.

By the way, Sorry to hear that about your cat!!

i'm wondering if i should get a new exhaust system or just a cat. suggestions anyone?

new walker cat installed. problem fixed. chevy wants over $600 dollars for an oem one. got a walker for $250. fyi.

I`ve heard gibson makes a nice system...
Don`t know if its really needed on a 4cylinder though.?
http://www.gibsonperformance.com/products.asp?pid=14297&make=22&model=488#488