Depending on how severe it would be down on power, Obd might show fuel trims way out but that would aventually throw a cel
Isolated the issue with a bad earth to fuel pump. Not sure on the reg specs but fuel pressure is 61psi at idle?
For future reference, is that earth close to the pump, Paul? My diagrams are telling me the earth point is "70092", but this is the same earth point as some of the instrument backlighting and the right hand side turn repeater. Weird.
Ian i believe that the earth wire has been damaged more than likely when the conversion was done. Its a very light gauge wire. I just made up a new earth strap and attached directly from the fuel pump assembly to the chassis under the undertray. Car starts every time !So Far! hahaha but i believe i have fixed it. At a later date i will remove the console again as the are a few earth wires terminated at the foot rest section on the LH side of tunnel. I have repaired a couple wires in there already due to a self taping screw damage GRRRRRRRR. Its all there to test our patience i think
Bravo, Paul I think we'll both get there eventually... in a roundabout way (In my case, hopefully after the major this year).
Is there a side note on your wiring diagrams that tell you where the plugs and earth locations are? I haven't seen this anywhere? Maybe I didn't print that bit out?
Unfortunately no data in this case. Quite a few of the earths are hard to track down. Only the Ferrari component number is known (Having said that, I'm only assuming that the 5.2's single pump earth is the same as the 2.7's left hand pump earth) I have a wire tracker, but the harnesses get really thick in places and the tracker signals get lost.
Pressure regulators seem to either cause overfuelling or underfuelling. Did you check for fuel leaking from the regulators into the vacuum hoses? (via broken regulator diaphragms) How robust is the rubber hosing? Any signs of softening? Image Unavailable, Please Login How does your fuel pump relay (N) socket and fuse (21) socket look on the relay panel? Any signs of melting?
? Why are asking —— you can test it with a fuel pressure gauge— at idle the pressure should be low (not sure of specs) around 2.7 bar (39 psi) or so and with the vacuum hose removed it should go up to 5 bar (73 psi) or so with a flow rate of 200 liters an hour ( 52 gallons an hour) or 3.3 liters an minute (1 gallon in a minute) This is probably the easiest and fastest way This is the pump I installed spec sheet Image Unavailable, Please Login Bosch Part# 058025023 Sent from my iPhone using FerrariChat.com mobile app
The reason I am asking is you cannot check mine or others Likely about half the production run or more as there is no Coupling to connect. Of course this makes checking the fuel pump supply pressureimpossible as well. You can of course disconnect and check flow but I know that does not always tell the whole story.
That works out to be around 3.6 liters a minute which right on with the spec sheet for the pump for Bosch Sent from my iPhone using FerrariChat.com mobile app
Thanks that’s good to know for the group Anyone still have news on a bad fuel pressure regulator and what the symptoms might be.
For info… It looks like the F355-compatible adjustable fuel pressure regulators are back in stock at spaturbousa.com https://spaturbousa.com/products/ferrari-355-456-550-512-in-rail-adjustable-fuel-pressure-regulator-e85-safe?_pos=1&_sid=90fc87b9f&_ss=r
Still need to devise an accurate way to set the adjustment on them. The dual regulator is a bit of a head scratcher on a 5.2 single pump car. Wouldn't the fuel rail pressures be tied together to a degree? They aren't isolated. So if 1 regulator is working and the other isn't, what is the result? The 2 are essentially working in parallel. If there were dual pumps and each bank was fully isolated like the early cars it's real simple. Not even sure if you could reasonably set them in circuit since I would think that one would impact the other. That makes me think you'd have to isolate / block off each bank to dial in the adjustment even if you got a gauge inline.
