How I fixed my missing/stumbling/cutting-out on"99 Blazer


rad153
12-08-2011, 06:13 AM
How I fixed my cutting out/stumbling/missing(Dec.2011)

With the guidance of my childhood friend who has been a mechanic for about 40 yrs., I was able to fix my 1999 S-10 Blazer 2WD 4.3L problem. I've got 160K on my SUV. The symptoms were that only after the engine was warm it would cut-out intermittently for a micro-second, it would miss intermittently or stumble intermittently. There was no pattern to the problem : whether accelerating or coasting & NO CODES being generated. Like 99% of Blazer owners, I changed fuel filter,air filter , cleaned the EGR valve and sprayed water on spk. plg. wiring to check for breaks in them w/ no real improvement. It had been exactly 60K since last tune up so I installed new dist. cap, rotor,wiring & spk. plgs.....Still no change in symptoms.. I called my friend Frank, he told me to disconnect the EGR valve & drive it X 15 -20 min. & report back findings . It improved very little. Frank then had me re-connect EGR valve & disconnect the mass air flow sensor & drive x 15-20 min. Voila!! All symptoms disappeared!!!!! The MIL lit up this time. I replaced the mass air flow sensor(Only new not reman. O.E.M. AC Delco per Frank's instructions). It cost me $ 236.00 out the door @ Full Service Co. in San Antonio,Tx.). The MIL reset itself after driving w/ new MAFS. BTW I did find a new one online for $111.00 before shipping but I didn't have the time to wait for it. It's been 4 days now & SUV runs like a champ. I also found a great website to help w/ diagnostics...."http://easyautodiagnostics.com/"; R.A. D.

gmtech1
12-08-2011, 05:26 PM
Thanks for the post!

rad153
12-11-2011, 11:13 PM
just need to give an important UPDATE to my previous post :

-12/11/2011...... Follow-up to How I fixed my cutting out/stumbling/missing(Dec.2011)

Yesterday the SUV starting acting up again w/ same symptoms but markedly less severe. This morning I started the SUV up (about 46 Degrees)..started right up & it idled for about 30 secs. & died. I started it up again & began moving wires/ connectors around & when I wiggled the coil wires I saw a spark between the to wires as they enter the coil connector. I shut down the engine & removed the connector, un-twisted the wire ,separated them away from each other & coated them w/ contact cement to insulate them. I drove the SUV all day & never had a hiccup. I guess that was the original problem? or that along w/ a bad MAF. Anyway..Happy it's all fixed!!! I write this so if anyone has this kind of problem ,they can check the coil wires for shorting. R.A.D.

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