‘90 348- intermittent power loss. Like flipping an on/off switch.

But switched back to two ECUs after the F355 5.2.... i.e. 360, 430, F40, F50, 575, 458, 599, 612, Enzo, California.... I think there are just too many devices (and in some cases cylinders) attached to the engine for a single ECU to handle.

e.g. the RH ECU on a 360 has over 70 wires attached to it. You have to take into consideration all the "fly-by-wire stuff". Databusses reduced the number of wires, but Bosch/Ferrari still persisted with 2 ECUs.

 

One engine ECU, this is what I am talking about.
Not talking about transmission computers and other computers on the car.
The fly by wire stuff and the dash and so forth is all can-bus.....pretty standard stuff.

 

Yes, that's what I was talking about, too.

The F430 has two 121 pin Motronic ECUs... with a total of 3 times the pins on the F355 5.2 ECU. There must be a reason why Ferrari/Bosch persisted with this. Heat management? Redundancy?

But we digress.

 

We are getting a bit off topic, but what I am saying is there is only a need for one engine ECU, not two like Ferrari seemed to do initially when they first started down the EFI route.
Its overly complicated for what is actually quite simple, also the whole MAF, narrow band O2 sensors and so forth, not necessary with todays tech...it was the best way back then, but certainly not now.

Additional computers were added for transmission, ABS, climate, etc etc which is another story and not what I was talking about because they are nothing to do with the Fuel, ignition management and so forth.....

And yes, things have become incredibly high tech now, and we will see what issues all that will throw at those cars 30 years down the track...

 

Just to clarify the CO potentiometer (the 383 Ohms) on the MAF. It has nothing to do with operation of the MAF as it is not connected in any way to the MAF's electronics (the CO pot is only physically inside the MAF for convenience of access). The MAF's signal sent to the ECU, representing the air mass, will be the same irrespective of the Ohms setting of the CO screw. This is because the CO potentiometer is connected between the ground and the ECU pin 43 so it trims the ECU for optimal CO. The MAF diagram below shows the connections of the CO pot - one side to the ground and the other side goes out via MAF's pin 6 (and to the ECU pin 43).
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With regard to "balancing" the CO pots at 383 Ohm, it will not actually balance the banks (the ECU-s) but it is only recommended as a starting point for balancing the two banks. The actual balancing of the banks is balancing the CO content left and right using a CO tester (exhaust gas analyser). This will most likely result in different Ohm values of the left and right CO potentiometers to compensate for small differences of the ECU-s, injector flows, FPR-s, O2 sensors etc. between the two banks.

 

I haven't made a video yet but last night I swapped my "working" MAF over to a borrowed good MAF so I now have fitted 2 known working MAFS and the car ran better than it has ever done - no hesitation upon hard acceleration - it was like a different car

Now that I know for 100% the cause of my problems I'm going to send my MAFS of rebuilding.

Couple of other things I noticed that may help others is that when I checked my relays some of them were a little bit loose so need pushing down firmly to make sure they were seated properly plus one of the wires out of the back of the fuse/relay board looks like it could of been shorting on the angled metal panel above it - worth just checking for anything like that.


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What sort of solved it for me was waiting for teh car to go into "problem mode" and then do all your testing rather than trying to test it whilst its working.

 

The MAFs get water intrusion actually and being 30 years old they are likely a source of running issues for may cars, not sure about the OP and Lucas's issue though that sounds like a bank dropping intermittently, the issue reported is not hesitation but actual power loss momentarily. Frankly if one plans of keeping and enjoying the car's I'd have them rebuilt just for good measure, pretty sure 30 years is beyond the EOL spec for the components and they definitely will not get better with time. But that's just me.

 

There is a pair of genuine Bosch MAF-s on Ebay: https://www.ebay.co.uk/itm/195290391099

 

I wonder who the seller is?! Lol ;-,)

 

Turn your cars on, oop the deck, push the back of the maf or wiggle the maf wire? Does it change idle, that could be your issue.

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Apologies for the double post - I get mixed up about which thread is which but have just tried the above test with 2 good mafs and the connecters seem good.

Connector Test:


Running with 2 good known MAFS - as you can see you can disconnect either side one at a time and although the car stumbles it won't stall. I've also been driving it this morning and it's running great.



I've just posted off 2 faulty MAFS to FIC so I'll let you know how I get on.

I'll also try this eBay one when it arrives in a week or 2 so we can see whether they are any good or not.

 

I agree with your thoughts...I nearly went down the Motec route a few years ago. If it was more plug and play I might have been more enthusiastic. To much of a purist.. I know the performance / drivability would probably been better overall having worked with Motec for years. Mainly race cars though. I accept its out of date but I can live with a few minor issues now and again. In twelve years Ive not had anything that couldnt be fixed easily including an ECU fail. Life with an older Ferrari eh. Would still be interested in the results of your venture if you go ahead . Hopefully it would be a positive experience for you...

 

I'm betting maf.or wiring still, check the wam for installing/setting the tps correctly, There is a tps setting post from Ernie out here as well.

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Those tempted by a standalone ecu may find this interesting - not a 348 obviously

 

That's where I got to as well, I thought there wasn't really enough of an issue with mine to justify doing an ECU swap. My car ran well on the dyno, WOT is great, the parts which aren't that great are lean cruise, idle during warm up, hot idle, hot start, and the odd instance where one bank just cuts out for a short time, all the usual issues you see people having. All this largely due to ageing components in a system which is so convoluted because that was just the way it was back then.
Since I can do the ECU swap myself, it makes sense to make it happen.
Im not a fan of Motech, I have been using Link ECU's since about 1992 so its what I know and easy for me to do.....

I'm not doing it for more horsepower, but going to just fine tune it for the octane fuel I use and for drive-ability.

Changing ECU's is not really a DIY thing, you need to know what you're doing, you need a dyno, and the time to do it.......Luckily I have all these things.

 

The MAF's wont make the engine cut out if they lose contact with the ECU. It will change it's idle and lean cruise, but wont make it cut out.
The ECU uses pre determined tables and TPS so that it wont cut out.

 

If you have to pay someone to do it, then I would not recommend it, not economically viable IMO, but you DO need to know what you're doing.
The guy in the video is onto it, the LINK ECU are very user friendly. Also a New Zealand company my friends business has been dealing with for nearly 30 years....

 

Why dont you swap the mafs round and see if the fault moves then you can confirm its the maf?

 

See post #42:

https://www.ferrarichat.com/forum/posts/149182483/

 

Yes, it reverts to using the per-deterimined fuel map inside the ECU rather than runtime values with the MAF and O2 sensors and so forth.
It wont make the engine cut out or lose power, but it could make it run rough if there are other associated issues.

 

I thought there was no cel lights.

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