Hi Gents, I was wondering if the fuel pump should run constantly when the ignition is on but the engine is not running. Mine does, so is it a problem? All the best, Bell.
Hi Bell, Answer is no unless somehow your Model works differently. Steve Magnusson would know as illustrated from this discussion. See this thread for full detail http://www.ferrarichat.com/forum/308-328/380752-electronic-ignition-fuel-cut-off.html Here are the excerpts below: No relationship between the ignition system and the fuel pump operation on your model. The fuel pump is controlled by the safety switch on the airflow metering plate device (unless the starter motor is cranking) -- if the engine stops turning = no air being drawn into engine = airflow metering plate not deflected = safety switch closed = engine start (injector) relay energized = fuel pump relay not energized = fuel pump "off". ...the "safety switch" of the airflow metering unit... it works like this: key in the "on" position (pos II), engine not running safety switch plugged in = closed safety switch condition = fuel pump not running key in the "on" position (pos II), engine not running safety switch unplugged = open safety switch condition = fuel pump always running as a test, you can unplug the safety switch (simulating an open switch condition) - now the fuel pump should always run whenever the key is in the "on" position (pos II) or in the "start" position (pos III) cheers
It a pretty clear sign IMO that someone felt there was/is a problem that needed "fixing" (but that's not my choice as a fix). What you are losing is the safety feature that shuts the fuel pump off in a bad accident where it's likely that the engine will stop running and there will be a break in the mechanical part of the fuel system, and, also likely, that the electrical part of the fuel system will stay working after the impact (if someone doesn't deliberately turn the ignition key out of Pos II). This wasn't so much of an issue on (simple & rugged fuel supply) carbed cars (but still it is a safety issue really). On the CIS injected cars (with a lot of noodly tubing, a zillion connections, and 20 times the fuel pressure), it's a much more significant safety issue IMO. As an Owner, I wouldn't let anyone else use the car unless we had a direct understanding that the car was modified and the User knew about, and assumed, the risk. As a Buyer, I'd deduct the cost to fix from the value (and have a lot more doubt about the overall fettling/sorting/care of the car) so don't see the upside to not getting it right. JMOs.
Hey Gents, many thanks for your input here, it's you guys again, and I really appreciate your help. Where is the pressure sensor cut off, I gussing this is the thing I'm looking for, is it Guys?. Also, Steve, what would be the reason for this 'dodgy modification?' Cheers Chaps! ;-)
Here is Steve to the rescue again! This man is an invaluable source of technical knowledge about these cars!!! I learn something new every time from these kinds of threads. http://www.ferrarichat.com/forum/mondial/162517-mondial-non-hot-start-problem.html ---> where is pressure sensor cut off??? ---> you`re talking about the "safety switch" of the airflow metering unit... it works like this: key in the "on" position (pos II), engine not running safety switch plugged in = closed safety switch condition = fuel pump not running key in the "on" position (pos II), engine not running safety switch unplugged = open safety switch condition = fuel pump always running as a test, you can unplug the safety switch (simulating an open switch condition) - now the fuel pump should always run whenever the key is in the "on" position (pos II) or in the "start" position (pos III) cheers Image Unavailable, Please Login
Hi Soucorp, thanks for reply and diagrams are a great help ;-) My switch is connected so Im guessing it could be a bad switch or connection to it or some kind of control relay from it? Mmm diagnosis and testing time I think... Any other thoughts would be a great help.... Cheers ;-)
