Random cylinder misfire. Could this be coil, or an ignition module??? Just looking for possibilities.
These are new plugs/wires/ and opti.
These are new plugs/wires/ and opti.
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Life is not a journey to the grave with the intention of arriving in a well preserved body, but rather to skid in broadside thoroughly used up and totally worn out, loudly proclaiming......WOW WHAT A RIDE!!! -
Random misfires could be from about a million things, but I would check the ignition first....... plugs, wires, coil, electrical connections, opti.......and then go from there......dirty/bad injectors, vacuum leaks, egr, PCM ground wires, etc...96 WS6 Formula: Ram Air, 383 Stroker, Ported LT4 Heads and Manifold, 1.6 Crane Rollers, 58MM T.B., AS&M Headers, Borla Exhaust, Meziere Elec. H2O Pump, Canton Deep Sump Oil Pan, 100 HP OF TNT N2O!! , T56 Conversion w/ Pro 5.0 shifter, SPEC Stage 3 Clutch, Hotchkiss Subframe Conn., Lakewood Adj. Panhard Bar, Spohn Adj. LCA's, BMR Adj. T.A., Custom 12 bolt w/ 3:73's, Moser Axles, Eaton Posi, Moser Girdle
11.6 @ 123mph (1.6 60' - getting there
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It simply means the PCM is seeing irregularities in the crankshaft rotational speed which it believes represent a misfire. Could be from any cause.... fuel system (injectors), igniton system (opti, plugs, wires, coil ICM), mechanical faults (valve adjustment, burned valves, broken rings). Could even be from an overly aggressive aftermarket cam, or even from driving over excessively rough roads that shock the crank position sensor. Not possible to narrow it down any more than that.Fred
381ci all-forged stroker - 10.8:1 - CNC LT4 heads/intake - CC solid roller - MoTeC engine management - 8 LS1 coils - 58mm TB - 78# injectors - 300-shot dry nitrous - TH400 - Gear Vendor O/D - Strange 12-bolt - 4.11's - AS&M headers - duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP/800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117MPH straight motorComment
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I would clear the code and see if it happens again. My wife's van did it 2 weeks ago. I cleared the code and it hasn't returned.2002 Electron Blue Vette, 1SC, FE3/Z51, G92 3.15 gears, 308.9 RWHP 321.7 RWTQ (before any mods), SLP headers, Z06 exhaust, MSD Ignition Wires, AC Delco Iridium Spark Plugs, 160 t-stat, lots of ECM tuning
1995 Z28, many mods, SOLD
A proud member of the "F-Body Dirty Dozen"Comment
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Already cleared it and it came on immediately. So how would you guys go about solving this? I mean so many possibilities, where do I start. I could just start replacing things, but I could get into lots of money before it is figured out. Like I said, the opti, plugs and wires were just replaced.Life is not a journey to the grave with the intention of arriving in a well preserved body, but rather to skid in broadside thoroughly used up and totally worn out, loudly proclaiming......WOW WHAT A RIDE!!!Comment
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You need to get it on a scanner and look at misfire counts. See if the PCM is picking out any individual cylinders. If so, it will make it easier for you. Check the spark plug, wire, and fuel injector (pulse test/check wiring) on the questionable cylinder.
If it truly is random and you cant find an individual cylinder(s) to blame, then I would test components that would affect all of the cylinders like the coil, or look for vacuum leaks, get a fuel pressure reading, check voltages on sensors, etc. If this is the case, it will be hard to track down, unless theres something obvious staring you in the face when you pop the hood.
And....it wouldnt hurt to start with a good tune-up if it hasnt been done in a while.96 WS6 Formula: Ram Air, 383 Stroker, Ported LT4 Heads and Manifold, 1.6 Crane Rollers, 58MM T.B., AS&M Headers, Borla Exhaust, Meziere Elec. H2O Pump, Canton Deep Sump Oil Pan, 100 HP OF TNT N2O!! , T56 Conversion w/ Pro 5.0 shifter, SPEC Stage 3 Clutch, Hotchkiss Subframe Conn., Lakewood Adj. Panhard Bar, Spohn Adj. LCA's, BMR Adj. T.A., Custom 12 bolt w/ 3:73's, Moser Axles, Eaton Posi, Moser Girdle
11.6 @ 123mph (1.6 60' - getting there )
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Just did plugs, wires, opti, fuel pump and filter, oil change, trans flush and lube. This thing is tuned up, so now it gets a little more difficult. I got the code from auto zone, but that does not tell me firing counts. Where can i get a scan that gives me these misfire counts. At this point I am thinking of taking it to a dealer to get the exact problem located. I am just tired of the problems I have had with this car since I bought it. I love driving it, but I bought a bad one that has given me nothing but problems.Life is not a journey to the grave with the intention of arriving in a well preserved body, but rather to skid in broadside thoroughly used up and totally worn out, loudly proclaiming......WOW WHAT A RIDE!!!Comment
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To access the "misfire count by cylinder" data, you need an OBD-II scanner that will read "GM enhanced parameters". AutoTap is a software system that will do that. High end handhelds like the Tech II will also read them. Obviously a dealer could do it, but he's going to charge you some $$$$$'s.Fred
381ci all-forged stroker - 10.8:1 - CNC LT4 heads/intake - CC solid roller - MoTeC engine management - 8 LS1 coils - 58mm TB - 78# injectors - 300-shot dry nitrous - TH400 - Gear Vendor O/D - Strange 12-bolt - 4.11's - AS&M headers - duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP/800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117MPH straight motorComment
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Are there any symptoms other than the code? Running rough or anything? My car throws that code often due to the cam. I was even told to have that code removed from the PCM to avoid the service engine light coming on.Silver 02 WS-6, 6 speed, Corsa cat-back, SLP lid, K&N filter, BMR STB, !CAGs, Lou's short stick, MSD wires, MTI "Hammer" cam, ASP underdrive pulley, Hooker LTs, Hooker ORY, Comp 918s, TR pushrods, UMI Sfcs, UMI LCAs, NGK TR55s, Hotchkis springs
Dyno'd 4/24: 330.9 RWHP/ 344.8 RWTQ (Before cam, headers, and pulley)
Dyno'd 5/1: 383.5 RWHP / 380.5 RWTQ (393 actual RWHP)Comment
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How much will the software cost me???Life is not a journey to the grave with the intention of arriving in a well preserved body, but rather to skid in broadside thoroughly used up and totally worn out, loudly proclaiming......WOW WHAT A RIDE!!!Comment
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http://www.autotap.com/Originally posted by RyanB58
I think T. Byrne sells the enhanced parameters GM setup for $275:
http://www.tbyrnemotorsports.com/
If you are getting it from the cam, you aren't going to notice any misfires. Its not misfiring, its because the crank irregularities that result from the cam overlap are not consistant with the crankshaft speed variations the PCM expects to see from the stock cam. Crankshaft speed changes don't match the expected pattern, so the SES light starts to flash. It would probably be a good idea to get it "programmed out", because the PCM might take some sort of actions to prevent what it thinks are misfires from damaging the catalytic converters. Not sure about that though.Are there any symptoms other than the code? Running rough or anything? My car throws that code often due to the cam. I was even told to have that code removed from the PCM to avoid the service engine light coming on.Fred
381ci all-forged stroker - 10.8:1 - CNC LT4 heads/intake - CC solid roller - MoTeC engine management - 8 LS1 coils - 58mm TB - 78# injectors - 300-shot dry nitrous - TH400 - Gear Vendor O/D - Strange 12-bolt - 4.11's - AS&M headers - duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP/800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117MPH straight motorComment
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Since having the GM HOT Cam installed two years ago, along with a complete rebuild, I throw that very same Code as soon as the engine is driven through it's Drive Cycle...about 250 miles. I believe my PCM has a Superchips program and was told from day one that the SES light will come on because of the Cam overlap, just like Fred mentioned. Everything under the hood has less than 3K miles and runs Perfect, so it must be the Tune? Only problem is that I just received my CT Emissions test date in the mail the other day and the car will not pass with the SES light on. No sniffer they just Plug into the OBDII port and read the data, so I will Fail immediately and then have 30 days to get it fixed or my Registration is voided. So, it looks like I might have to unfortunately shell some $$ out for an LT1 Edit Tune, because what I have now is obvisously not working. Only Item in my Ignition system that has not been replaced is my Cap & Rotor...but the New MSD Kit has not been shipped as of yet.
Sorry if I didn't help you out RyanB58.
1997 Camaro LT4 SS #093Comment
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