Buddy has a 97 - that's a 5.2 ;)
This is from a 1997 US manual. So must be something different between US and ROW cars, which doesn't make sense to me.
You may be correct. My 95 manual has it. The copies of the 97 and 98 manuals I have do not. The section of the WSM that discusses this was prepared in 94 and contains only the 95 2.7 model year wiring diagrams. I would think it not applicable to later 5.2 models. OBD II does hold a lot of thing when the battery is disconnected where as OBD I can be cleared with a disconnect.
Ok. Well that is interesting. Thank you johnk. I have both the original owners manual in paper form and the correct owners manual in PDF form for my '98 Euro F1 car (note they do change with serial number). Neither of them mention this re-setting procedure. In the absence of any better advice let's just say do what your manual says and leave it at that!
Are you sure your manual is for a 97? You can tell by checking, for example page A4 where it shows the fob used to arm/disarm the alarm. A 95 manual would not discuss the alarm system.
No need for a flame suit, Dave. I jumped onto this thread only because I've never heard of this procedure before in relation to my car, and I would have expected to if it was a big deal.
The flame suit was in reference to my warm up comment which was a source for much debate when I created a thread about it a while back
The 355 is arguably ahead of the curve to utilize numerous smart logic; the convertible top and the mainly F1 system to name a few. These logics however are mechanical switches, levels and limits. These do not require electrical power to maintain memory. It is the physical state they are in allowing them to channel electrical signals to the "ECU" of their status. The "ECU" in turn channels electrical signal to other components. Simply put, the 355 logic system is collection of dummy devices working in unity to perform a function. Ironically, these simple dummy devices summed up the Achilleshiel of the 355's. A device failure become a system failure. The good thing is they do not require constant electrical power to maintain memory. And from experience with my car, I believe the F1 system has a soft memory hard settled into the "ECU". The shift points are always at a precise RPM depending on my driving style. I don't think any component in the 355 that require reseting other than the clock and the radio if it was from the 80's. This summed up the unnecessary need to let the car run for system reset after a battery disconnect. Everyone has a common practice we adhere to daily but if we, to utilize a "common practice" of a shared interest, we need to know is it practical or a waste of time. The latter I believe is true. I could be wrong. I'm all ears on this matter.
Steve, my 1998 Australian delivered Spider has the page L7 precautions as described by others. When you say Euro model, do you mean Euro-spec, or Euro-delivered? Perhaps you haven't had any problems because you live in a "temperate" climate (apart from the occasional record-breaking 40C+ heat wave) Cheers Ian
Thanks Ian. My car is originally UK delivered. Both the owners manual that came with the car and the correct downloaded version do not mention the procedure. As a general comment, it's important to make sure to download the correct manual for your particular car as there are differences. The whole thing seems a bit odd, really. I guess it is possible that climate comes into it (it never gets below about 5C here, but can be 45C in summer) but that wouldn't explain the differences in the owner's manual. Is it possible that this is a stick / F1 thing? Cheers.
Seriously,every single car on the road that uses a MAF and not a set speed density programming chart teaches itself to run best in all kinds of different loads and RPM. Lirretally tens of millions of cars. They slowly adjusts their own maps the entire time you drive. All these adjustments are lost when you unhook the power. Why Ferrari wanted to make a big deal about it is beyond me. The only thing it will do with idling is relearn how to idle, where the idle air control valve needs to be to idle at the set rpm. The most basic of data points. Literally thousands of data points will not be learned / adjusted from default until you actually drive the car. If you start the car and throw it into gear right away and drive the worse thing you risk is it not having time to adjust the idle air control valve so the car might die when you push in the clutch rolling up to your first stop sign.
A nice monograph on OBDI, OBDII and Drive Cycles here: Introduction to OBDII - NAPA Institute of Automotive Technology
I read the first 14 pages of that and skimmed the rest. I see a lot of explanation about OBDII being different from OBDI about focusing on monitoring emissions and about all those monitors but I didn't see much about the underlying engine management programming that would be pretty common between the 1 & 2 systems. Which is what this is really about, losing recorded engine management maps. Returning to the default settings and relearning its adjusted settings throughout the entire rpm and load ranges. I believe it is about engine management programming and not OBD difference. Again it might explain some in there, I didn't read it all but intended to go back and read it all when I have a minute although it's 20 year old material. There are two ways for a computer to run your engine. The simplest is by speed density. That has like read only memory with parameters that were calculated and set permanently. These engines do not run a mass airflow sensor. They take a limited amount of input to select a map with set values that tell to what the injector pulse length should be for the right A/F ratio mixture etc. Very basic utilitarian, ham fisted engine management. With today's technology I don't think there are many car companies that have stuck with this method but there have been plenty in the past. The right way to do it and the way the 355 is ran is with a computer that takes in more imput and can make fine adjustments on its own. Using a MAF to actually calculate the amount of air entering the engine and actually using the O2 sensor to monitor how rich or lean the A/F mixer is by monitoring the exhaust and the computer actually using that imput to control injector pulse, timing etc to make the engine run at optimum performance. This computer has default settings but memory it can write itself and "learn", slowly adjusting the maps throughout the rpm and load ranges so that when you return to that rpm and load it is already fine tuned for what is likely the best outputs but it keeps on monitoring and slightly adjusting maps always to the exact conditions of the time. I guess I'm just rambling, hopefully you can all understand what I'm trying to explain.
While I don't know the algorithms, the relearn concept makes sense to me and I'd question the motivation in the OM's and WSM if it did not have a purpose.
The relearning process drive cycles became more complicated when Motronic 2.7 went to 5.2 In practical use, when my F355 Challenge needs to be refueled, the battery switch is turned to cut off power, the car is pushed out of the garage for refueling and then pushed back in. Before I go out on a session, I restore power with the switch, start the car, and drive out of the garage to the corner worker's station to wait until I'm released onto to the track. I sure hope my car learns fast. . Image Unavailable, Please Login Image Unavailable, Please Login
I usually let the car warm up and idle when the power has been cutoff. I also have not done it that way a few times and I noticed no differance. I still generally let it relearn because I have the time and like Dave said I would think if it was worth their ink it likely has some level of importance.
Dave, I would go out on a limb and say that it is probably because the Ferrari engineers wanted the car to be in closed loop before you took it out. When you first start you car it is in open loop and running like a speed density engine, it ignores the sensors until the engine gets to a set operating temperature then going into closed loop and can learn. When cold sensors like the O2 sensor give very inaccurate data and you don't want your engine learning or trying to run on erroneous data. Heated O2 sensors greatly reduced the amount of time it takes for them to read right. Literally the only thing you engine can "learn" in this state is where to position the idle air control valve and that's usually pretty close to where it needs to be. It should only take a short time for it to get that right. There are three stages of engine management. First is cold start- only last a short time- rich mixture makes momentary high idle Second is open loop, running on default settings until operating temp reached. Third is closed loop. Reading the sensors and making adjustments- recording newly learned settings. The one other time your car will go to hard set maps is at wide open throttle. No learning or sensor imput there just calculated settings from the factory to make the engine sing. All this thread does is tell everyone that the best approach is to use a trickle charger and leave a couple years of stored up experience for your car to work from and quit erasing it for no reason. So I think getting it into closed loop was there objective by telling you to let it idle.
My thinking as well. How did challenge cars do it if they had to wait at idle for 10 minutes after every refueling? The same is said of the 348. I never do it. Ever. I cannot discern a material difference in initial drivability. Kai
