David,

one more suggestion (that I should have thought of when you first raised the
problem) is checking the wiring to the ECU. i.e. check the pins at the
connector (according to Bentley) for the right resistance/continuity/voltage
etc.

Maybe, just maybe the wire(s) is(are) bad.

Alistair

PS the old method of vacuum leak detection is by using propane (or
ether!!)...directing the gas around the suspected areas and noting if the
engine changes speed. But if the damn thing won't idle in the first
place....!

on 17/04/2002 9:18 PM, David Marshall at vanagon@VOLKSWAGEN.ORG wrote:

> The continuing saga of my Digifant II I4 in my Syncro 16 - to recap the
> problem.
>
> It will fire up and instantly die, if I hold my foot on the accelerator, it
> will run, very rich and very rough.
>
> I have tried two known to work AFMs and ECUs, replaced the poorly spraying
> injectors, replaced the fuel pressure reg, new spark plugs, new wires, three
> different coils, three different coolant sensors, two different
> distributors, and checked the timing everywhichway from Sunday.  Now I am
> desperate - it won't go and now it is warm enough to do some camping... the
> last thing I want to do is pressurize the intake manifold by setting my air
> compressor to 10PSI and plugging it into the pipe that come from the crank
> case vent.  I will be blocking off the air intake boot with some ABS
> plumbing plastic - this leaves no way for the air to get out other than a
> vacuum leak - right?  So at 10+- PSI, how much air should I hear leaking and
> where should I hear it leaking from?  Why am I doing this - I had the intake
> manifold shaved down a little so it would fit better - as far as I can tell
> there should be no vacuum leaks caused by this, but that this point, before
> I rip it out and install a Turbo Diesel I want to exhaust my fault
> possibilities.  Is there any timing at which all intake valves will be
> closed?
>
> Thanks in advance - should have tested this motor out of the van first! :)
>
> David Marshall