crmvette

replaced dual mass flywheel with steel single mass,noisey and vibrates as expected. now seems to be setting mis-fire code any one else have this issue-could they be related. thanks for any input.


Rick

crmvette

dont understand this forum. have heard nice things about this group seems when ever i ask a question i get no or very few respones. is me or how i put the the out there---just wondering

sailorsteve

What year is your car?

What do you mean by "mis-fire code"? Do you have a code number?

Sargevette

Knock sensors?

crmvette

it is a 96 and intermittenly sets a p0300 will clear itself. just wondering if related to flywheel change

sailorsteve

The '96 is a hybrid OBD1-OBD2 diagnostic system. Not familiar with it, but I think that code is set when a slight variation in crank speed is detected, as would be the case with a misfire. I could picture that code being set off by the sm flywheel, as the trans rattle would then be directly relayed to the engine. (Just a guess- you didn't hear it from me)

crmvette

thanks sailorsteve,makes sense,was just wondering if other owners had same issue(no---didn't hear it from you)

jeffp1167

I have a 97 Camaro that has had mis-fire detected but not sure if it is even close to the "hybrid" obd1-2 system. But in order for it to have that kind of code set there has to be a resistance change in the spark plug circuit .. plug wires/coils/plugs. A rattle won't cause it, I would be more inclined to say the knock sensor is hearing it.

My misfire detected was from a plug wire that was blistered and brittle. My 3.8 has a great deal of engine related noises but only time misfire detected was plug wire related.

good luck

94vettelover2

If the problem happened after the work-its 99% of the time from the install.That 1% is coincidence.My guess would be a knock sensor as their sensing knock then adjusting computer & computer reads as a slight misfire.I've read too many problems(here) when not sticking to the dual mass flywheel to not ever recommend installing anything else even though expensive.I wouldn't keep driving the car & don't ignore this problem.Keep us updated on what you find

STL94LT1

1996 was pure OBDII, no hybrid.

Bronze85

First year for OBD II for Fed. Emmisions.

sailorsteve

But I was under the impression that the '96 still uses the old-style ALDL connector and that there are some other slight differences in the diagnostics. Is this not the case?

STL94LT1

sailorsteve, 94/95 uses an OBDI PCM with an OBDII ALDL. Maybe this is what you are thinking about.

sailorsteve

Thanks for the info. I'm always the last one to find out about anything.

hooked073

that code is set when there is like a 3% difference in RPM's at set points. Lets say at a steady 1500 if between the firing of one cyl to the next is more then 3% it will set a code. The bad part is untill latter years was tech good enough to idenify what cyl it was coming from. Jeff the ECM does not measure resistance change in the wires,plugs ect. I am sure what happened with your car was it had a miss from a bad plug wire that missed was picked up by a difference in the RPM's. To the PO I do not think the noise would cause what you are expericing but it may be possible that you new flywheel is not balanced right and causing a RPM veraince. But I would be sure you do not have a slight miss.