Hello, I have a 2002 Spyder and am testing the fuel pressure as i'm experiencing fuel odour while driving. With the car at idle the fuel pressure is 50 psi as per spec on both fuel rails. When turned off, they both drop to approx 36 psi over the course of 1 hour which is within the specified range of 35-43 psi. But with the key in the ignition on, engine off position, the passenger side fuel rail primes to approx 46 psi, but the driver side is at 0 psi. Thoughts?
I'm not sure if this is normal or not. I know on my F355 Spider, my (single) pump primes for a specific time period when the ignition is turned on. From then on, it requires the engine to turn. Even if you cycle the key, it will not prime again. I couldn't find anything in the 360 manual stating that this happens. Experts? Anyway, assuming your car is left hand drive, is your right hand fuel pump running continuously with the key ON? Or does it just run for a few seconds? When ignition power is applied to one of the 360 engine ECUs, the ECU does a quick internal test, then powers the respective master Motronic ECU relay (behind the seats). This relay then sends power to the fuel pump relay. All that the fuel pump relay then requires is an earth (for the relay to operate to send power to the pump). This earth comes from the ECU (pin 30). The ECU needs to see the engine turning (40 rpm) to apply an earth. Suggestion: try swapping the fuel pump relays to see if anything changes or perhaps look for a permanent earth on pin 2 of the RH pump relay (socket) with power off. Compare the signal on the LH and RH relays. Image Unavailable, Please Login
good fuel pressure DOES NOT mean you do not have a leak somewhere a no-leak fuel system DOES NOT mean you have good fuel pressure
You must first find the source of the fuel odour. This is most important... One should never smell raw fuel. Go from there.
rollover valves are a source. Also, the top of the fuel pumps fail and puddle fuel on their tops. check both.
Of course I was referring to the priming, not the fuel smell. Assuming there is no visible signs of liquid fuel, check the evaporative system plumbing. Image Unavailable, Please Login Plumbing varies according to age and market.
Mine is a 2004 and the rollover valves and fuel pumps have all already had to be replaced. It's probably time!
Thanks. The leak is being addressed, but I'd like to know if the right fuel pump priming at 46 psi and the left at 0 psi during key on, engine off is normal. The car starts up and runs fine, so I'm curious as I couldn't find any info in the shop manual.
In the absence of a response on the forum, will you be running any tests to see if there are any broken bits? I had a look at 3 different Ferrari 360 documents and couldn't find any mention of priming. Looking at the car's predecessors, priming is mentioned for the following cars in their respective WSMs: 456M (5.2) ignition on - runs for 2 seconds F355 (2.7) ignition on F355 (5.2) ignition on - runs for 2 seconds only F550 ignition on - runs for 2 seconds only Even though most of these cars have dual pumps and dual ECUs, the WSM pump doesn't specify whether one or both pumps prime. The ECUs and pumps are described singularly.
I may find some time this week to check the relays as you suggested. For anyone looking to perform a fuel pressure check, here's a reference as the procedure is quite simple.
