backfire through intake

zxkevinxz · 02-27-2005, 03:38 PM

'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.

amac209 · 02-28-2005, 04:22 AM

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.

zxkevinxz · 03-01-2005, 08:27 AM

it's distributorless which is newfangled/foriegn to me

vtmecheng · 03-01-2005, 09:02 AM

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

kenyonja2007 · 03-01-2005, 11:07 AM

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

vtmecheng · 03-01-2005, 03:25 PM

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

NaKeDZX · 03-01-2005, 04:01 PM

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.

zxkevinxz · 03-08-2005, 08:33 AM

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.

NaKeDZX · 03-08-2005, 11:46 AM

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

zxkevinxz · 03-09-2005, 07:43 PM

you'll probably get some mpg back at least

blazer-in-trouble · 03-10-2005, 01:31 PM

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...

zxkevinxz · 03-15-2005, 01:30 PM

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...

blazer-in-trouble · 03-15-2005, 01:42 PM

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.

blazer-in-trouble · 03-15-2005, 01:43 PM

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

zxkevinxz · 03-15-2005, 01:52 PM

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

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