misfire?
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Launching!
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From: CenTex
misfire? Hey guys, hopefully someone can help me with this, I'm tired of driving around town and my car sounding like crap, and getting bad gas mileage lol. 97 z28, has a miss when it goes into closed loop. The codes it has is of course po300 for the misfire, codes for the rear o2's (they aren't tuned out) and p1351. One of my scanners says ignition control coil a circuit malfunction, The other says IC circuits 1&4 malfunction or shorted. I've had the p1351 since I've bought the car but I've never had any no start issues. I already changed out the o2's with brand new denso's. I've researched the p1351 threads but none I found had a definite solution to the problem. I'm thinking it's some kind of sensor or something that is only uses in closed loop or could that not necessarily be the case? What do you guys think? Thanks. -Kyle
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Joined: Oct 2011
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From: Keller Tx
Hey guys, hopefully someone can help me with this, I'm tired of driving around town and my car sounding like crap, and getting bad gas mileage lol. 97 z28, has a miss when it goes into closed loop. The codes it has is of course po300 for the misfire, codes for the rear o2's (they aren't tuned out) and p1351. One of my scanners says ignition control coil a circuit malfunction, The other says IC circuits 1&4 malfunction or shorted. I've had the p1351 since I've bought the car but I've never had any no start issues. I already changed out the o2's with brand new denso's. I've researched the p1351 threads but none I found had a definite solution to the problem. I'm thinking it's some kind of sensor or something that is only uses in closed loop or could that not necessarily be the case? What do you guys think? Thanks. -Kyle
Exact problem as you on my 97. Changed the O2's, new plugs, new opti, I did just get an ICM I am going to try this weekend along with spacing the coil away from the head a little. Runs perfect when cold like crap when hot and get the PO300 code.
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From: Knappa, Oregon
My code reader book says P1351 is "Ignition Diagnostic Monitor Input Circut." Don't know what that means. And of course P0300 is "Random/Multiple Cylinder Misfire."
Are you are sure of your coils and wires? And does your '97 have the Opti Spark distributor system? '98 and on have separate coil-on-plug ignition and no distributor at all.
Read up on the Opti Spark and you may find the answer to your problem, I am not familiar with these distributors but I have heard them mentioned as a source of problems.
Are you are sure of your coils and wires? And does your '97 have the Opti Spark distributor system? '98 and on have separate coil-on-plug ignition and no distributor at all.
Read up on the Opti Spark and you may find the answer to your problem, I am not familiar with these distributors but I have heard them mentioned as a source of problems.
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Launching!
Joined: Oct 2011
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From: CenTex
Jr. Yeah, I spaced the coil away from the head last week but I guess if the coil or icm has already been overheated then it wouldn't help now until I got a new one. I'm going to check all the wiring for a short and then to run by u-pull-it and get an icm, if that doesn't work then I guess I'll get a new coil. Ghardester; I've read several opti threads but none of those cases seem to be quite the same as mine, and that is definitely the last part I want to replace! lol
