Hello folks, looking for some help: I think it makes more sense to look for help with the posters in this forum for engine issues on a T. I bought the car on the word of a supposedly trustworthy mechanic. As it turns out, she has some problems. The 1-4 bank has pretty much stopped working at all. At this point the only time it runs on 8 is right after disconnecting the ECUs from power. Doesn't last long though. The car's phase, (stroke) sensor had been disconnected. When I connected it, it just ran worse - would barely idle on 4 cylinders, whereas with it disconnected, it at least will idle. I checked the codes and got 4111 and 4112, but not sure if those were from before or after connecting the sensor. I tried switching sides on the ECUs and thermocouple boxes. That bank has a brand new Oxy sensor so that can't be it. Any ideas??? One item that is getting taken care of soon is the flywheel/dampner assy. AFAIK it has almost no grease. Even when she was running on 8, she vibrated at low revs, and made a clunking noise at idle with the clutch engaged. Am I correct in assuming that the clutch pack slides right out after removing the exhaust, the little cover, the ring nut, and the big cover? I can't find a torque spec for the ring nut. Anyone know? One theory that I have heard is that the vibration resulting from the non-functional dampner is causing the rev sensor for that bank to misread, and thence be ignored, resulting in the shutdone of the bank. With no rev senor codes I doubt it, but in any event that possible cause will soon be eliminated. Thanks and best regards, Randy Lee
You should not be hearing a clunk sound at idle with clutch engaged. There may be a few things to test/try at home, but you may have a case where authorized Ferrari service makes more sense. You are going to want to put an oscilloscope probe into the connections for your crank sensors and phase sensor, for starters, to see if you are getting any sort of reasonable wave pattern from each...but that's not going to solve your clunking sound even if one of those sensors turns out bad. You are also going to want to disconnect your exhaust ECUs to briefly test if the car runs on all 8 cyls without them. They are a pretty common cause of running on 4 cyls only. You might want to use a timing light to see which cyls are getting spark while running, too. It matters if you are losing evens or odds or all left bank or all right bank, etc.
Thanks Nodoubt for diving in. The clunk sound is normal for a 3.4 whose flywheel/dampner has lost its grease. Without enough grease, it fails to dampen vibration, and in fact makes it worse. That is why re-packing it with the correct 105 grams of special grease and installing a new o-ring to restore the seal ASAP I know which bank is not running: the 1-4. If I drive it a bit, the 5-8's catalyst is nice and toasty and the 1-4 is hardly warm, plus after about 1.5 miles, the 1-4 Check Engine light comes on and stays on. I checked spark, and all 8 are there, but as far as I can tell, no fuel. I switched both the ECUs and the exhaust ECUs from side to side, to see if the issue followed one of those components, but no dice, so I conclude that the probem is not likely them. Again, thanks! P. S. I have the factory shop manual and cannot find the torque spec on the ring nut. Help!
Nice work. You've got two fuel pumps and fuel filters, one for each bank. Each fuel pump has its own relay. Each relay has its own fuse. It's quite likely that your "no fuel" condition is therein above...because an ECU issue (engine and exhaust, both) would shut off the spark signal, correct? Since you've got spark, I'd swap fuel pump relays and replace the fuses (just to be sure) to see if the problem switches sides. If so, it's a relay problem. Easy fix. If not...then it's likely a fuel pump issue (could be a clogged fuel filter, though). Easy to test the fuel pump by hotwiring the fuse box, too. There's a picture by Miltonian on that very thing somewhere around here.
I know thats right... my flywheel was modified to permanantely remove the grease (by the previous owner), and the whole thing was welded together as if it was 1 piece. I have the clunking sound when my clutch is engaged at idle. To me, the sounds is more like a typical wasted throwout bearing. It drives me nutz, but the cost of replacing the flywheel is obscene... if you can even find one!
But it won't cost you but about $100 to pull the clutch, open up the flywheel, and add the kluber grease. Sure, the flywheel doesn't have to have the grease if said flywheel has been welded into one piece, but adding the grease back in might balance it and cushion it enough to minimize that klunking sound, I'd guess. Cheap and quick and harmless to try, anyway.
Perhaps, but my understanding is now that it has been welded together, taking it apart to add the grease is not an option. I was told that it was heliarc welded, which would be a nighmare to grind away (if even possible)... then I would have a major balance issue to address. It really seems like I dont have any options other than replaceing the flywheel... if I want to eliminate all the racket. The plan is the pull it apart in the next few weeks and get a good visual on everything, then I guess i'll know for sure what needs to be done.
Before diving into anything CHECK YOUR BASICS FIRST!!! Do a check of the MECHNICAL HEALTH of the engine. Compression, leakdown, cam timing, condition of the electrical for the ignition system, including the plugs. Check to be sure all the connections at the modules are clean and making good contact. Check the MAF sensor connections check the throttle plate gaps, check for vacuum leaks, check the condition of the exhaust etc. All these items need to be checked before taking apart anything. If you have a poor foundation, then you will get all kinds of codes and odd things happen that can seem like an electrical issue but its really a mechanical one. Lots of time and money have been wasted throwing parts at a car with a bad cylinder because the computer says you have a bad o2 sensor. The ECU only knows the electronic health of the engine, NOT the mechanical health of the engine.
tbakowsky, I understand what you are saying about the basics, but this time I don't think it is all that relevant. Recently the car was running very well, especially considering that it was in continuous injection mode. (It must have been, as the phase sensor was unplugged.) (The phase sensor was probably unplugged to hide the fact that the idle is likely not set up correctly.) But we are not talking about a rough idle. We are talking about a complete shutdown on 4 cylinders. Sure, when I get it running on 8 again, I am likely to have to have a pro do a correct idle set-up so that I can run the car using sequential injection. But the current issue is the same whether the phase sensor is plugged in or not. (The only difference being that on 4 cylinders it will idle with the phase sensor unplugged, continous injection apparently being more forgiving.) I am going to try switching the relays, but I don't think that it's the fuel delivery system either. It does briefly run on eight after unplugging the ECUs. This brings up a good question, that my reading of the factory manual leaves unanswered: When a bank is shut down by the ECU, what gets shutdown? The spark, the fuel or both? Anyone know? TheOnlyest, try GT Car Parts, (623) 780-2200. Really good guys with used parts. You know that funny thing about that (sad) story is that it has me thinking. Maybe when I do mine, I will see about a more permanent seal. I mean, gee, if the guy had put the grease in first, then welded it, it might work right and last! I guess that I don't really see how you could weld a lid on a bucket of grease, but I am not a welder? I don't know, maybe some kind of super epoxy would reinforce the O-ring that apparently gives out every x number of years. What about that ring nut? Have you any information re torque. Hey guys, again thanks for any and all input. Even if I don't agree it is very helpful that you guys bring all this stuff up to help me think about it.
Thanks for the tip on GT Parts. I'm not much of a welder myself, but I would think the grease wouldnt react well to intense heat of the heliarc welding process. Do a search here in the 348/355 section on that... lots of info has been posted.
When I re-pack my flywheel, I am going down to R. S. Huges, the Loctite distributor, and have them tell me which of their fine products will re-inforce, (or perhaps even replace) the o-ring. Will report. I forgot to mention: I have gone over the connections to the MAF sensors, the ECUs, the Phase sensor, the O2 sensors, and the Thermocouples. They have all been treated with Wurt CU800 electrical contact grease. Thanks for reminding me to try searching the forum! Best regards, Randy Lee
I always thought that CU800 was copper paste for preventing brake rotor rust...very bad for electronic connections. Was I wrong?!
I blindly took the advice of an old racer mechanic. You may be right about it's intended use. Will report after further investigation.
Try this: Get some good electrical contact cleaner and clean up all the connections, ALL OF THEM. Hook everything up, minus the catalytic converter temperature ecu's (unplug them). Double check that your grounds are all hooked up properly. Disconnect the battery for 15-30 seconds, reconnect it, then with the car in neutral start it and let it idle until the cooling fans kick on, or until you get a check engine light. Be sure to have all of the accessories turned off, and don't touch anything, just let it idle. Try that and get back to us.
To me, there is a difference between an "electronic" connection from an "electrical" connection. You could probably convince me that copper paste is "ok" for an electrical connection like a battery post, but you'd have to work to convince me that it's OK for a data-carrying electronic connection.
I have been doing some reading from the 348 club, and was thinking the same damn thing, although I didn't have all the details like you suggest - Thanks Much for that!!! Will report the results tomorrow.
Guess what? After following your advice there ernie, my beloved Mondial is now purring like a kitten. Wheee! I love you guys!!! OK, next the flywheel. Randy
