Mazda Rotary Club

General => General Technical => Topic started by: jackaleks on February 21, 2010, 04:03:47 PM

Title: releasing fuel pressure
Post by: jackaleks on February 21, 2010, 04:03:47 PM
i can\'t start the car, so i can\'t do the usual trick of pulling the fuel pump relay out :(
 
is there a \'manual\' way of doing it (other than pulling a hose off and pointing it somewhere safe)?
 
cheers,
Title: releasing fuel pressure
Post by: Aubec on February 21, 2010, 04:20:01 PM
I don\'t think so mate - the fuel has to go somewhere, its either through the injectors or out through a hose.

Pick a line that you can get as easily to undo, and wrap lots of rag around it to stop the fuel spraying everywhere when you tug the hose loose.
Title: releasing fuel pressure
Post by: SiH on February 21, 2010, 04:33:08 PM
If you can\'t turn the car over, then tbh, Just get a rag and put it over the union when you pull it apart - done it plenty of times. Usually becaus emy fcukwittery gland is hyperactive and I forget to release the pressure...
Fuel rinses out of your eyes pretty quick :)How long has the car been standing? If it\'s a while, then it will be pretty low anyways :)
Title: releasing fuel pressure
Post by: rx7boy on February 21, 2010, 06:39:52 PM
Quote from: jackaleks;673937i can\'t start the car, so i can\'t do the usual trick of pulling the fuel pump relay out :(
 
is there a \'manual\' way of doing it (other than pulling a hose off and pointing it somewhere safe)?
 
cheers,

Im a bit confused, why would starting the car have any relation to pulling a fuse out, am i missing something ! to release fuel pressure just open up fuel filler?
Title: releasing fuel pressure
Post by: Aubec on February 21, 2010, 07:37:57 PM
Quote from: rx7boy;673981Im a bit confused, why would starting the car have any relation to pulling a fuse out, am i missing something ! to release fuel pressure just open up fuel filler?

Yep, you\'re missing something :)

He\'s talking about pressure in the line between the pump and the injectors, which is always pressurised to some degree.

The \'right\' way to release the pressure is to pull out the relay whilst the engine is idling.  The pump stops pressurising the rails, the last of the fuel is injected into the engine and burnt and then engine comes to a gentle stall, leaving the lines safely de-pressurised.
Title: releasing fuel pressure
Post by: jackaleks on February 22, 2010, 08:42:14 AM
looks like i\'m going to be adding \'petrol\' to my growing list of motor related colognes :) my favourite is still 17 year old gear oil, though...
 
thanks!