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Misfiring problem.. Probable Causes?

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Old 11-12-10, 05:39 PM
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Misfiring problem.. Probable Causes?

My fc is having a misfiring problem. It will usually miss when I let off of the gas pedal by about 20%, and it will continue to misfire until I either completely let off the gas or completely get back on the gas. It's pretty annoying when the speed limit drops to 50 and I can keep a steading speed because my car is tripping out!

It seems like either the little window in the air intake will slam close and open, or maybe like the fuel flow will just stop for a split second over and over...

Can anyone tell me possible causes of this from most to least probable? And how should I go about trying to troubleshoot this?
I am not a mechanic by the way!


Thanks!
Old 11-12-10, 06:23 PM
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When you pull the foot off the throttle the TPS causes a fuel cut to occur and I believe the amount of fuel cut depends on how much and how quickly the foot comes off the pedal. If you haven't set the TPS to 1 volt after the car is fully warmed up then go ahead and do so.

Also, when the foot comes off the pedal there could be some backfiring due to a problematic Anti Afterburn valve located in the ACV. Check the Fuel-Emissions section of the service manual to check this item.
Old 11-13-10, 01:47 PM
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Thanks satch.

Will check those out after work.

And earlier I was looking around and noticed a broken wire (bottom arrow in the pic) and found where the wire is supposed to connect (top arrow in pic). Is that a ground or something? Could that be the source of my problem?
Old 11-13-10, 01:56 PM
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Originally Posted by JerettGranger
Thanks satch.

Will check those out after work.

And earlier I was looking around and noticed a broken wire (bottom arrow in the pic) and found where the wire is supposed to connect (top arrow in pic). Is that a ground or something? Could that be the source of my problem?
?????????
Old 11-13-10, 01:58 PM
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lol forgot to attach tha pic!
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Old 11-13-10, 02:43 PM
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That's the Port Air solenoid and is an emissions only component and is supposed to work only during the first 20,000 miles (100,000 to 120,000 miles as well and so on). There are supposed to be 2 wires in the plug, Black/White which is the voltage wire w/key to on and the Brown/Yellow wire which goes to the ECU and the ECU dictates whether the wire has a ground on it or not.
Old 11-13-10, 04:50 PM
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so when my car hits 300,000 to 320,000 will I need that connected or will it be ok if I leave it off?
Old 11-13-10, 05:32 PM
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Originally Posted by JerettGranger
so when my car hits 300,000 to 320,000 will I need that connected or will it be ok if I leave it off?
You can leave it off just make sure the wires leading to the solenoid are taped off and not grounding out. Not talking about the wires coming out of the solenoid but rather the ones leading to it.
Old 11-13-10, 06:29 PM
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Thanks Mr. satch.
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