Another misfire, opti or coil or o2's??
08-19-2008, 09:07 PM
#1
Another misfire, opti or coil or o2's?? Hey everyone I recently developed a misfire again. I have new plugs and new wires and they are good. However the opti, coil, and o2 sensors are original with 135,000 miles on them. The mis is not too bad at idle but under load it feels like its on seven cylinders and backfires a lot. I'm not showing an ses light either. Any help would be great. Thanks
08-19-2008, 10:02 PM
#2
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What year your car is might help. If it's obd-1 year, you won't get codes anyhow. You say it happens at idle and under load, but at what rpms under load, it being a high or low miss could get you different answers.
Start with the cheapest first, which I believe is the coil, then 02's, then opti. I say do as much research and testing as you possibly can before spending more money than you can by throwing parts at it. These engines are notoriously difficult to find misfires with.
Start with the cheapest first, which I believe is the coil, then 02's, then opti. I say do as much research and testing as you possibly can before spending more money than you can by throwing parts at it. These engines are notoriously difficult to find misfires with.
08-19-2008, 10:40 PM
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Id say check the coil first also. My car would drive fine with light load, but as soon as id tromp on it it would misfire and cough, no engine light either
08-19-2008, 11:40 PM
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If you check those and all is good, then you start thinking things like opti...
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08-20-2008, 01:27 AM
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There's a way to test resistance of the coil with a volt meter I think. Do a search here and on camaroz28.com, I know I've read it someplace. May have been on Shoebox's site -
http://shbox.com/page/index.html
Another tip, use factory/AC delco parts as much as humanly possible. People buy coils from their local parts store (who usually don't stock OEM factory parts) and they fail after getting hot from the block.
http://shbox.com/page/index.html
Another tip, use factory/AC delco parts as much as humanly possible. People buy coils from their local parts store (who usually don't stock OEM factory parts) and they fail after getting hot from the block.
08-21-2008, 01:15 PM
#10
OPTI TIME... well i saw above you checked the wires but was wondering if you did that buy a visual inspection with the motor off/on? i like to check my wires at night with all the lights off... a bad wire will most certainly throw a very visible spark, usually grounding out on an exhaust manifold, egr valve, face of the block
but unfortunately i believe your opti is crapping the bed. a stock opti with 135K on it... congratulations
but unfortunately i believe your opti is crapping the bed. a stock opti with 135K on it... congratulations
08-22-2008, 03:52 AM
#11
I checked them in the day time so I could get a good look at everything. Then I checked them at night so I could see if anything was arcing and I didn't see anything at all. No sparks at all. So I guess opti is next or should I try the o2's
08-22-2008, 04:13 AM
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I'm not one to have you throw parts at it either, but I would put new o2s in it just for piece of mind and maybe even better gas mileage. And as mentioned, use ac/delcos.
08-22-2008, 02:46 PM
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At the very least the 02s will give better gas mileage and piece of mind as mentioned above.
