Hello: I have a 91 348 TB with 17k miles. Bought from Tonkin in Oregon 4 months ago. Initially the car was great. However 3 main issues now: 1. "Check Engine 5/8" comes on and then a significant loss in HP. 2. Windows are frozen. Door locks and power windows won't work. 3. Slow Down "1-4" and "5-8" lights come on often. Even at startup and at 10mph.... Thanks in advance. David
1. Start by cleaning the electrical connections in the engine compartment -- have you aggressively washed the engine or left the car sitting in the rain? Use an over-the counter contact cleaner (CRC) from PepBoys or Autozone or whereever. You may want to apply Stabilant-22a to the connections too. The CEL lights are a bit less common to illuminate than the slow-down. Mine came on after an engine washing episode. I cleaned the connections near the coils, and all worked perfectly. 2. Did you check fuses and relays first? Do the window switches illuminate? Check the rubber hose that connects the door wiring to the car. It is a twist off connector, and the pins often fail. Once you confirm that, we can discuss how to fix. 3. Slow down lights are either a sign of your cats failing (probably not at startup & 10mph) or a failure of your cat ECU's. You're getting the problem on *both* banks of the engine? Before going too far, tell us about the emission testing requirements in Virginia -- that may lead us to a cheaper solution involving test pipes and no cat ECU's. HOWEVER... I defer to the much smarter people here -- if *both* slow down lights are coming on, it may be an indication of something different. Usually just one light comes on, and the owner can swap the ECU from one back to the other, thus tracing (watching) the slow-down light move sides.
I agree with JRR. The window problem is usually from failed wires at the twist on connection at the door hinge. You can push the wire connections out and run a continuous wire through the door hinge area and make the connections inside the door and wheel fender where the wire will not flex and break over time. I had Tim Stanford's shop do both doors on my 348 and it took them about three hours total (around $250). BT
To find out what is turning on the lights you need to pull the codes from the main ECUs behind the seats. Do a search on the site and you will find the proceedure and the code descriptions. The loss of power is usually the exhaust ECU cutting out one bank of the engine. On my car the check engine lights were a result of bad O2 sensors (Lambda sensors). If they are bad you can get replacements at any local parts store that sells Bosch products. Much less expensive than from a dealer.
Here is what you need to do for this one http://ferrarichat.com/forum/showthread.php?t=73034 These will help http://ferrarichat.com/forum/showthread.php?t=16348 http://ferrarichat.com/forum/showthread.php?t=70995 http://ferrarichat.com/forum/showthread.php?t=64488 And for this one http://ferrarichat.com/forum/showthread.php?t=16859 http://ferrarichat.com/forum/showthread.php?t=57066 In case you didn't notice, those are threads I found in the archives. If you try searching the archives you will find plenty of info. One more thing. Welcome to the 348 Brotherhood. I was looking through your past post, and didn't see a proper welcome to the Brotherhood. So welcome aboard.
Pretty consistent "Check Engine 5/8" light on. First it will be fine, then when I accelerate after about 5 seconds, there will be what sounds like a valve [?]giving in and a dramatic loss in HP, then the light comes on. I did fix the relay problem with the contact cleaners and now my windows move up as slow as it was when I bought it. Thanks! Will get the codes deciphered, and keep you all updated. It's great to have this resource! Thanks! Another Pic for you all!
Check those connections ! http://ferrarichat.com/forum/showthread.php?t=58847&highlight=motronic+junkies
David, I switched my ECU from 1/4 to 5/8 and problem went with the ECU. The funny part is, it is On when engin is cold and about 2-3 minutes after start the light goes away. The car runs and drives well. So being in portland Metro Area with all the rain/miosture I am too thinking that a good connector clean up will do the job before changing. By the way I do all of my own services, how about you? How is your gear shifting, I added a bit of STP to my tranny new oil and it shifts well. But remind you that I totally avoid going to 2nd gear as it is sized improper, unless you shift at less than 15m/h.
You can try to reset the ECU. Disconnect the battery for about ten minutes, then reconnect the battery, start the car and let it idle for about 15-20 minutes. Do not touch the throttle or any other engine controls. This will clear the error codes on the ecu's and let them remap your a/f mixtures, etc... I did this and my 348 has been great for about 10 months now. BT
