Re: Hard-starting 1991 100s

[Michael Murphy <mmurphy@nais.com>]

Phil Payne wrote:
> 
> In message <7F44DB86FC64D21197A50008C75DB04A3255D1@saexch-mb1-stf.sikorsky.com> "Norman, Victor J" writes:
> 
> > I have a 1991 100s (non-turbo, NF engine, CIS-E III). It starts fine from
> > cold, but if I turn off the ignition after the car has warmed up and then
> > immediately try to restart, it will not start. If I wait just a couple of
> > minutes it starts with no problem. A little embarrassing if I stall the car
> > in the middle of a busy intersection....
> > Any suggestions on fixing this problem would be much appreciated.
> 
> Speculating ...
> 
> System pressure leaking down _fast_ leaving control pressure so high
> that it holds the air mass sensor paddle down?
> 
> Over a minute or two, control pressure will also leak down, releasing
> air mass sensor paddle.
> 
> Diagnostic check would be an interesting variant of the standard
> residual pressure test:
> 
> a) Attach fuel pressure gauge - tap open.
> 
> b) Idle engine to temperature.
> 
> c) Shut off engine.
> 
> d) Jumper fuel pump relay socket to run fuel pump.
> 
> e) Close gauge tap to read system pressure.
> 
> f) Shut off fuel pump and watch gauge.
> 
> A very rapid decay (<10 seconds) would indicate you've found the
> problem.

Good speculating Phil.  And the culprit (on my 89 100 with same problem
as Vic's) was the fuel pressure check valve.
--
MJ Murphy