Ok, bad news. I celebrated too early. This morning after a 20 mile drive without any issues, the misfire came back a couple blocks from home. So I pulled into the driveway and the misfire was very noticeable both with the added vibration and the exhaust note. I plugged in the OBD2 scanner and read real data stream. The LT fuel trim on bank 1 has gotten worse to 8.5%. And there is a clue this time. The O2 sensor B1-2 is stuck at 0.810V and not changing at all while the same O2 sensor on bank 2 is down at 0.200V. No misfire CEL permanent or pending. I don't know if the ECU uses the signal from the post cat sensor in its engine management but … I might just change that out too. Then, the next thing to do if that does not solve it is to swap all fuel injectors from left to right and see if the problem follows.
I should have mentioned this earlier. Goth got rid of a misfire separating the wires, when they got hot they cross fired. I had the same issue with an MSD box, did this to the wires mis was gone Image Unavailable, Please Login
Even with brand new Kingsborne wires??? The GOOD news is the misfire is now permanent so I can readily troubleshoot it now. I suppose I can separate the wires first to see if it helps... Or, change to another coil...
I forgot about that. The valve cover design on the 355 is pretty elegant and pretty lame too. Some of us are running great functioning good looking MSW COP units on the 550's and the results are so good I'm never going back to wires even for a platinum concourse award. I'm not sure why the COP idea didn't take off on 355's. A few guys have done it and there is a master thread on it here.
Yuuuup!!! I have 2 full COP setups one for the 348 one for the 355, just need to get around to it rekon
Finally !!! Now there is permanent failure with a misfire on bank 1. I swapped out the coil, no difference I removed the top plate off the valve cover and moved the wires away from each other, no difference. I pulled off each plug wires at the coil, and isolated the misfire to cylinder number 3 (that is good news) I checked the spark with a replacement plug all the way to the end, and it has strong spark. I removed the spark plug, checked compression and it was good. The plug looks wet so it has fuel. I replaced the plug, and the misfire is gone. Visual inspection before just could not identify a bad plug... until it permanently fails. Takeaway here is to change all your plugs to new ones first.
Just a general word of advice. This is not a good thing to do. We have all done it, I have too. But, to quote a mechanic from another site 'cause I know you won't believe me, To be honest, I don't know if this can happen in a 355 due to the wasted spark ignition. But hope this is the end of the thread. Good that you appear to be up and running.
Interesting. 40+ years of wrenching never seen a bad spark plug. They are so stupid simple and robust and 100k mile life is not out of the question for one. Color me skeptical...
I had a bad spark plug on my BMW 335xi. OBDII code took me to the proper cylinder but the codes can't determine if it's a coil or plug. The coil was cheap and I had not changed plugs in 50K miles so I bought a set of plugs and a coil (COP). Changed the coil first - no change. Changed the plug(s), problem solved. Plugs go bad.
Threw me off too. Especially at the beginning when it was only intermittent .... But hey, I am happy its gone.
I'm skeptical, too. A fouled plug is usually a symptom, not a cause. At the track (I race vintage bikes and cars), racers are always bumming spark plugs off me when chasing down fueling and ignition misfires. I always tell them "spark plugs are never the answer." Time will tell. Good luck.
You are right, except that I now have bad plugs with both my 355 now. That is the symptom, and the problem is I park them, not drive them, and only crank the engine over to move them up and down the drive way. The Berlinetta had the same issues with plugs.... cranked it over 5 times, move it 20 feet each, plugs dead! The 95 Berlinetta plugs don't go dead permanently, just bad running with a misfire that cannot be pinpointed to a single cylinder. The Spider started with excess unburnt fuel and came down to one solidly dead plugs in the end. All plugs are getting tossed this weekend.
Each winter my 98 sits for 6 months. Fire it up and it runs perfect. Oh yeah, it's an F1 too Mitch I've actually not even driven my car this year so it's been sitting in the garage since August of last year. Been too busy. Perhaps I'll get it out 4th of July.
It would be preferable to leave it 6 months in the corner of a big shop, on jack stands..... But, I don't have a shop. As for the F1, there is a $15,000 premium on a 6 speed Berlinetta over the F1. 8500RPM's recent selling price confirmed that.
Untrue. I cannot disclose the details but very recently I connect a buyer and seller of an F1 and the sale price was much higher than any documented gated car. Perhaps Entropy's blue 355 sold for more but we don't know the sale price of that car. Pristine cars fetch high values.
8500 RPM car sold for $60K on BAT, and it was 98 F1, Berlinetta, low miles, paint corrected, and mechanically close to perfect. I know that car very well... Maybe there is one person that will pay $80K for that car but he was not in the market.
I reviewed the car. It was a nice car but it doesn't hold a candle to the car I'm referring to. The owner is also going the extra mile now and sparing no expense to make the car as new. We are refinishing every single part and I can tell you the car will be the nicest 355 in the world when he is done with it.
Well then, he is one of a kind, and there are no other buyers like him. I drive 8500 RPM car in person and have seen it many times, I can tell you that it is at least a 9/10 car.
Respectfully to Chan - I don't feel that car was close to a 9/10. Just my opinion when I reviewed the listing photos. I would not even classify my 98 F1 as a 9/10 right now as it needs a front bumper respray and a redo of the interior parts. And, plenty of buyers like him. Much of these deals happen behind the scenes and are not public. Truth is, low mileage, pristine 355's are getting harder and harder to come by, gated or F1. Another customer of ours who we also recently refinished the full interior of a 95 B paid premium money for it and IMO, got a great deal for a low mileage car.
