348 no sparks on 4 cly

Hello,

Have 1 problem with my 348 ts.


From time to time during drive I loose spark to 4 cylinders (right or left side not sure). I have to take off and on the ignition for a short time 1/2 sec and it is ok.
This happens in random periods (1 time per drive to 5 times per drive). I have a feeling that it is more common in the last month or so.

Any one has an idea what to do as it is really disturbing especially at night when the lights turn off when you take the ignition off during drive.

Cheers

 

Thank you.

My 348 has cats and lights on the dash.
And they go on sometimes (randomly and they should not be on), but when the spark dies and lights go on it is not connected it is all more random.
Sometimes lights left or right, sometimes the sparks die it is not connected.

Will replace the cats with test pipes to see what will happen as I noticed a little reduction to the performance in the last coupe of drives (maybe one of the cats had colapsed)

Will also reconnect and relube the sensors and change the spark plugs to see it helps.

Cheers

 

How do I operate this button.
I am very very bad concerning electric

 

Thank you.

Today I started it up and it ran like a 5 cilynder tractor (also when warm.

Opened the engine lid and disconnected both LMM sensors from airbox and reconnected them while engine ran. The car ran great afterwards. Different noice great performance like nothing ever happened.

Will go for another drive tomorrow to see if it will go away or not.

It really is a mystery because sometimes she works and sometimes not.

Cheers

 

This site is worth more than anything else I ever found on or off line

Thanx a million 3forty8

I think that my problem is moisture in the ECU (I admit that I wash it more often than I drive it )

I am almost sure that this text contains a solution to my problem will go at it step by step and let you guys know what was the solution in case that something similar happens to someone else.

"
Slow Down Lights
Common Causes of 348/355 "Slow Down" Warning Lights and/or Reduced Performance:
Your 348 or 355 may encounter a "half power" condition in which an entire bank of cylinders appears to be shut down. This shutdown signal originates with a thermo sensor on a cat, goes through an exhaust ECU that is located under each shock tower under the rear engine hood/bonnet, and procedes to your dash warning lights and Air/Fuel ECU's that are located behind each seat in the cockpit itself. After 5 minutes or so of showing the SLOW DOWN 1-4 and/or SLOW DOWN 5-8 warning light, your A/F ECU's will shut off on or both banks of cylinders. Your SLOW DOWN 1-4 light is located on the *right* side of your instrument cluster; your SLOW DOWN 5-8 warning light is on the *left* side.
This is because your engine's 1-4 cylinders are on the right side of your 348, and your 5-8 cylinders are on your left side.
Ernie suggests that you get some Permatex black silicone. It costs about $3 for a tube of it. Then after you have taken the car out for a nice Italian tune-up-drive (the heat will help evaporate moisture that's already penetrated these old units), jack up the rear, remove both rear wheels and inner fender liners, unbolt/unplug and pull out both of the exhaust ecu's and seal them up good with the silicone (seal everything except the electrical wires, of course). That should keep the moisture from getting inside the cat ecu (the main killer of these $400+ parts), and then it shouldn't be able to build up the condensation from sitting all night.

I bought a new $20 laser thermometer (for sale at Radio Shack and other such places). You point the laser at whatever you want to measure (e.g. catalytic converter, air conditioner vents, etc.) and it tells you the temp (up to about 420 degrees F, anyway). Well, after a normal city traffic drive plus a little idling, my 348's cats typically register 370 degrees F to 395 degrees F, give or take. Above 420 degrees my el cheapo meter just blanks out...which would be up toward the temps that might indicate a cat overheating issue (especially above 650 F).

Anyway, if you measure the temp of your cats and you get a low temp such as the above, then it probably isn't a cat overheating problem.

On the other hand, a high cat temp (glowing a dim red would be bad!) is cause for concern. It could be coming from unburned fuel (e.g. bad spark plug) entering a cat. Could be from a clogged cat.

So what ECU codes are in memory? No need to guess blindly. Swapping the exhaust ecus is a fine idea to see if your SLOW DOWN lights switch sides, but the error codes will let you be even more clever about your debugging in the first place. So the first thing to do is to pull your Check Engine codes. One of the potential codes is for cat temp being too high (would be good to know!). Another code is for a faulty/unplugged exhaust ecu. Good to know if either of those codes are in memory, among others.

You should have a red button tethered to a cable to each ECU (if not, they are cheap to buy from Ricambi America), see pic below for ECU.

Your two air/fuel ECUs are behind your seats. The 5/8 is behind the U.S. left-side driver's seat. The 1/4 ecu is behind the right side seat. You'll want to pull the codes on the same side as your SLOW DOWN light (so for the SLOW DOWN 1/4 light, you'll pull the 1/4 ecu codes).

There is a large panel behind the seats that covers the ECUs in the Spider, or two smaller panels for the 348 TS/TBs. You just put a flat-blade screw-driver onto each of the black plastic "screws" and turn 90 degrees to remove the panel(s). Then you can see the ECUs (and hopefully their cables/buttons).

NOTE: If you pull only a 4444 or 4114 code (with the engine off), then your SLOW DOWN light may be coming on due to your engine computer being turned off (cycled) by its ECU relay under your passenger footwell. When the power is turned back on, your engine ECU and exhaust ECU will perform their self-diagnostic tests, which will flash the appropriate CEL and SLOW DOWN lights (even while you are driving!). If that's the case, then no code other than the "all clear" 4444 code be saved in your engine ECU for that side of your 348, because the error codes are not kept in memory when the power to an ECU is turned off.
Swapping engine ECU relays is a typical test in that circumstance to see if the problem switches sides.


Oh, and for whatever it's worth, I highly recommend paying West Marine or an on-line store (http://www.interlinksolutions.com/firefoe.htm) the $130 for one of these automatic fire extinguishers for your engine bay. It's cheap peace of mind for our high-performance, gasoline-burning machines.


Do any of your spark plugs appear fouled? Notice any misses? Backfires?
One such cause may be a bad spark plug wire (which is typically encountered at low RPMs but not at high RPMs). A bad plug wire means a bad spark burn, which means that excess fuel goes unburned and into your cats, which can overheat your cats, which leads to a Slow Down light or two prior to a failed cat (or two) or a car fire. Slow Down lights are important safety warnings.
1. Modern Ferrari spark plug wires generally do not suffer failures that will be found with an ohm meter. The problem they suffer is a breakdown in the insulation allowing them to "Leak" or short to ground or another wire. The loss is not always even complete.

It is compounded by the fact that unlike American cars where the standard has always been to elevate, insulate and separate the wires to prevent just that, the Europeans (as very well shown on the 355) tightly bundle them and cram them in a hot grounded metal area that requires an absolutely perfect wire to perform properly.

Standard repair method on 348, 355, 456, 550 for rough idle [or power loss] not immediately attributable to any other cause:
A Throw away the Champion plugs and install NGK's.
B Install new spark plug wires.
God bless coil on plug ignition. - thanks, rifledriver
http://www.kingsborne.com/html/ferrari.pdf
Not only will Kingsborne custom make your Ferrari 348 spark plug wires (about $625 per set with lifetime warranty), but they'll wrap them in 1200 degree color coordinated external sleeves: http://www.kingsborne.com/insulatorsleeves.htm . Also, http://www.magnecor.com/ will custom make your 348 wires for less than $170 per side. In addition, T Rutlands typically carries aftermarket wires for 348's in stock for around $650.
Another cause may be your cats, MAFs, O2 sensors, exhaust ECU's, or a bad Ground connection.
2. Catalytic Converters. 348's and 355's have dual "cats" that each have a temperature sensor and an exhaust ECU. If your 348/355 runs too rich, or if one or more of your cats becomes covered with debris or insulation or rust, or if your cats become clogged over time, then your exhaust ECU's will trigger a Slow Down warning. You have two "slow down" lights on your dashboard, one for each bank of cylinders (1-4 and 5-8) that feed each cat. These old technology, baffled cats will glow a dim red when too hot, and can cause catastrophic engine fires if allowed to continue to heat up. If you drive slower, i.e. "slow down," their temperature will often (not always) decrease.
(left side exhaust ECU location pointed to by Miltonian's famous cue stick)

(exhaust ECU)
The exhaust ECU's can also generate false warning signals (either from bad ECU's or from bad connections or from a bad thermo sensor). This typically happens when water has penetrated your exhaust ECU framing box(es). It could also happen if the thermocouple on the cat has its two wires shorted together, and could likewise trigger a false signal if either or both of those thermocouple wires are broken (open circuit will trigger a CEL).
In either case (real overheating or false signal), the 348 and 355 ECU's will first light up your appropriate Slow Down light (1-4 or 5-8), and if the warning from the exhaust ECU(s) continues (usually about 5 minutes), will shut off the entire offending bank of cylinders. At best, your car will then run on only four cylinders, at substantially less than half power (a "limp home" mode).
The typical repair process starts by examining the cats after a Slow Down light has been lit. If either or both cats is/are glowing a dim red or otherwise emitting a large amount of heat, then your Ferrari should NOT be driven any further and other diagnosis procedures below should be avoided or handled by professionals. At that point you will to identify which components need replacing such as O2 sensors and cats (preferably with more modern Hyper-Flow converters) before proceeding. Both O2 sensors and catalytic converters eventually fail. You may need to replace your spark plugs and/or spark plug wires and ignition coils, too (because fuel that is unburned in your cylinders will heat up your cats). You may need to clean your air filter and lean out your A/F mixture, as well. At the very least verify that the resistance measured between male pins #1 and #6 on your MAFs are identical and close to the factory pre-set 383 ohms (see section on A/F mixture adjustments/tuning). Your timing may also need adjustment, ditto for fuel pressure regulation and fuel check valves.
If your cats are NOT emitting a large amount of unusual heat, then simply switch exhaust ECU's from one side of your car to the other. This will let you test for a bad exhaust ECU. If your Slow Down warning light then changes from Slow Down 1-4 to Slow Down 5-8 (or vice versa), you have identified a bad exhaust ECU. Replace it or send it out to be repaired (e.g. to BBA-Reman).
If the Slow Down light does not switch sides after you've moved your exhaust ECU's to opposite sides of your car, then attach a clean, new, additional Ground wire to your O2 sensor (and then likewise to a Ground point on your frame) on the offending side. You may also have to replace your exhaust temperature sensors. Also, insure that your exhaust thermocouple is in proper condition. *thanks, No Doubt
To help identify which components have failed, you generally follow the same tactic of switching sides. Our 348's are set up in a mirrored fashion such that we can move components from the left side of the engine to the right side, and from the right side to the left...now, when a problem switches sides after a component swap, then it usually means that was the offending component.
I'd suggest switching coils from left side to right side to see if the problem switches sides with a bad coil, if not, then I'd try swapping the left bank of 4 spark plug wires with the right bank of 4 wires to see if the problem switches sides...which would identify a bad spark plug wire.

Measure the resistance under the MAF cable on the male MAF #1 and #6 pins (extreme ends of the cable connection, but on the MAF itself) with the engine off. You should see identical resistance values on left and right sides (for reference, the factory pre-set value is 383 ohms).

You can then swap MAFs from left side to right to see if the problem switches sides in order to identify a bad MAF.

If none of the above helps, then the cheap thing to do would be to swap cats from left to right side to identify a failed/clogged cat (if the slow down light swaps sides then, of course).

"

 

Solved the problem.

One of the spark plugs was bad and did not work all the time (like blinker indicator sometimes yes sometimes not).


It looks like there was wrong lambda value since there was one spark misfiering and CPU was shutting down left or right side and car was not running ok.

New spark plugs. All sorted purs like a kitten.