That would make sense that the engine only runs on one bank, and doesn't set any fault codes. Shutting it off and restarting might get the relay working and it will then run on all eight cylinders. How did you diagnose it? Was the problem sporadic, or did it happen on a regular enough basis so that you could track down the cause?
It might have set a code if the relay coil had failed. The Motronic ECU controls the relay coil. The ECUs seem to monitor the coil circuits of at least some of these relays. Interestingly, the left bank fuel pump Speed 1 relay coil circuit is in parallel with part of the Evap Test Pump circuit. Issues with the Evap Test Pump have been known to cause a Fuel Pump "B" fault message. Counter-intuitively, fuel pump "B" seems to be the Speed 1 pump.
Page 125 or 126 in the owner's manual for the rest of the Left Side Passenger Compartment relay-fuse descriptions. The cool/cold start issue on this 2008 430 Scuderia ( a friend's car) was always intermittent. The local Ferrari dealership guessed at an oxygen sensor issue and replaced one. That did not correct the problem. When the start problem did happen, my friend had to shut off engine and wait maybe ten minutes then start engine again. The engine either operated normally or he had to repeat the wait then start process. We looked for similar issues with other F430 and 430 Scuderia and associated solution, but did not find an exact match. My friend thought maybe; voltage too low, a loose electrical connection, Ignition ECU issue, a fuse, or a relay issue. When the failures occurred he did not smell unburned fuel from the left cylinder bank exhaust. When the ECUs checked out he moved on to fuses and relays.
When I purchased my 2009 430 Scuderia in 2015 I noticed a cold start issue. When started, it would idle roughly and not at a higher cold idle I would expect. If I shut off and immediately restarted, it was fine, idling smoothly and faster. It would do this about every other cold start...perhaps every third cold start. I mentioned it to Ferrari of Seattle and the service manager Eric mentioned there was a software update they could perform to correct this. I had them do it, (it was very inexpensive at the time, perhaps $125 labor) and it never recurred after the update. That was 10 years ago.
Is this the same relay? https://www.fcpeuro.com/products/mercedes-relay-bosch-0025421119 Also having intermittent cold start issues and this seems to be a cheap thing to try.
The other gentleman's new relay has the same Bosch part number on it . If the old one has 5 pins, don't panic. Only 4 are needed. Suspiciously cheap. How much is postage? If the relay failed, one bank wouldn't work. Are you sure that's what is happening with your car?
It looks like my car has a different model relay (2006 coupe), 0 332 017 300. That one seems to be tough to find, maybe superseded? Both banks work, however I do have a bit of a rough idle at cold start and trying to rule everything out. I know old relays can underperform even before failure, so I figure it’s a cheap/easy item to try. I also cleaned the MAF sensors which look OK (may replace if not solved in other ways) and added Techron to the fuel tank. I don’t pay postage for FCP as I live near them for free pickup.
What I normally do is Google the data sheets for each relay part number. The 0 332 017 300 is 20 amp, so a (-007) 30 amp relay should be ok power-wise. Sometimes, however, you have to look at the impedance of the coil, and whether it has diodes or resistors across the (internal contacts). The 300 and 007 both have resistors across the coil. No diodes. The -300 coil is 78 ohms +/- 6 ohms. The -007 is 75 +/-6 ohms, so it's probably compatible due to the overlapping values.
Interestingly ChatGPT is convinced that the original part has diodes: “- The 011 007 is confirmed to use a resistor - The 017 300 is consistently listed (by Bosch and OEMs) as a diode-suppressed relay.”
I fed it this doc and it admitted I was right all along. ChatGPT is wrong so often, it’s kind of disturbing https://www.bosch-ibusiness.com/media/images/products/relays/xx_pdfs_3/2022_10_01_relay_powerpoint_catalogue_en_converted.pdf
I also used that reference in your last post. It has the "resistor" box checked/ticked and the symbol doesn't look like a diode. Yeah, ChatGPT and other AI's leave a lot to be desired. I've probably mentioned this a few times before on FChat, but AI quoted me once on a post I made... which I later retracted because I later discovered I was mistaken. AI didn't mention my retraction.
Tried the new resistors and it started up no problem. I noticed a bit steadier RPM. It’s still a little rough, but at least with that cold start up, seems a bit better. Will be interesting to see how it feels after sitting overnight. Other things I’m going to look at are motor mounts at some point (though the motor is pretty static when driving), replacing the battery, new MAF’s, maybe proper injector cleaning. Battery is on a tender, but 3 years old and these newer Optima batteries don’t have the best reputation for longevity. Replacing the battery on my similar vintage V8 Vantage drastically improved idle on cold starts. It was worse than the 430 for sure.
Yeah, the issue is “AI” is a misnomer. It’s an LLM that “guesses” the answer to your prompt by pulling in a bunch of resources. It never admits it’s unsure.
There was actually several different revisions of the firmware for the same MY and some do indeed fix cold starting and stumbling issues, starting on one bank, etc. You can see this on the part number of the ECU after the the dot. E.g. 226587.001 from 31/01/2008 226587.002 from 24/06/2008 This makes it difficult because the same 6 digit Ferrari SKU part number is used but it could have potentially DIFFERENT software on it! Normally the 3 digits of the sub revision is printed on the ecu label (assuming they even bothered to update the label, doesn't always happen either!!!) Its quite a common problem on a lot of different Ferrari models suffer this. Many of the issues where related to software problems that got fixed, then forgotten about and fixed again on a later model. It appears to me that only under situations were the customer actually complained did the factory issue an update to the dealers so very few cars got updates, even as late as 2009...
