Vacuum pipe diagrams

[paul mc]

Hi, i have an air leak in the fuel system somewhere on my 1987 3.5 V8 EFi, if i block the air inlet in front of the air filter the engine slows right down and nearly stalls but not quite, surely if i completely block the air inlet it should cut out?

I am looking for a diagram showing which vacuum pipes should go where as during the rebuild i may well have mixed up a couple, there is one loose which i have blocked off which used to run to the heater matrix, but as i took it out i just blocked the pipe. I thought i saw a diagram in the RAVE manual but have just looked through it and can't find it now.

Any help much appreicated.

[SteveRK]

The crankcase breather pipes that connect to the inlet plenum chamber will be enabling the engine to continue to run i suspect.

mines hot-wire so likely to be different but your connections will include:

fuel pressure regulator connecting to rear of plenum chamber

idle speed stepper motor link pipe from rear of plenum to air intake adjacent throttle butterfly

brake servo take off at plenum chamber

heating system vacuum reservoir at plenum chamber to n/S inner wing spherical plastic object

Crankcase breather from O/S rocker cover to T piece that connects to plenum ch' & throttle housing

Distributor vacuum advance to throttle housing

[FridgeFreezer]

Depends how you're blocking it really, engines idle with the throttle closed and a minuscule amount of air passing the throttle plate, so unless you've done a bang up job of sealing your airbox (including the drain holes etc.) and blocking the end I don't think it's that surprising.