fuel injectors (-10sp)

[quk@sievers.com (Phil Payne)]

In message <199706040542.PAA15107@morden.netpci.com> "Mark&Michelle Sousa" writes:

>> The Bentley gives good testing procedures, but without the right tools
>> you are literally playing with fire...

The fuel pump can deliver around 3.8 US pints/minute, so forgetting to
re-attach a fuel line in the engine bay can produce spectacular results.  I've 
also seen mine hit 16 bar in the fire-up peak, so the joints need to be pretty 
tight, too.
 
My favourite approach, when I'm playing around with fuel lines, is to have the 
doors open both ends of the garage so there's a good through draught, and to 
fit a push-button remote control into the fuel pump relay socket.  That way, 
when you think you've got everything tight, you can just pulse the pump to put 
some pressure on the system with the ignition still off and check for leaks.
 
It's also useful to stuff rags around any areas where you're going to loosen 
fuel lines, and wrap a rag around the wrenches at the instant you undo the 
flare nuts.  This has two purposes - it lets you catch the small amount of fuel 
that _always_ comes out (the contents of the accumulator - a fluid ounce or 
two - it can spray _very_ unpredictably) and it catches any of the copper 
washers that drop off. When everything's back together, before restarting or 
doing the pressure tests, you take the rags out and toss them outside.  If you 
do it properly, you shouldn't have any loose fuel around the engine area.  If 
you can see fuel moisture anywhere, don't switch on the ignition.

It's a good idea to get four or five of each size of copper sealing washer - 
the book says to replace them _every_ time but they'll usually survive five to 
ten careful dismantlings.  They're tinned, so they're shiny, but they're 
actually copper inside.

--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club