[Rovernet] Rovernet Digest, Vol 74, Issue 3

[magnet at ican.net]

I had the identical problem some years back on my P4 90.  Turned out to 
be the first item on Charles' list -- partially blocked mesh screen on 
the pickup tube in the fuel tank.

Cheers,

Bill Daddis

On 06-Jul.-2019 9:12 a.m., Kellogg, Charles via Rovernet wrote:
> Lots of things to check here: Possible blockage of fuel pickup tube in tank
> (old crud in tank covering tube). Incipient failure of fuel pump diaphragm,
> points screw or vacuum advance plate securing hardware may have gone loose,
> distributor pinch clamp bolt not tightened after recent tune-up (turn
> distributor by hand to rule out looseness), (or other distributor-related
> issues), either high- or low-tension lead came loose from its contact,
> either at the coil or at the distributor, dirty points contact surfaces,
> sticking piston in carb (unlikely), fuel tank not venting properly causing
> high vacuum/impeding fuel flow (Fuel cap hissing when opened during
> inability of engine to rev up) , slippage of lever or bellcrank on throttle
> linkage or accelerator pedal on shaft ( best: 2-person check to assure full
> throttle action at carb to reflect pedal action ), cold start cable pulled
> out but slipping when pushed back in (leaving carb choked with warm
> engine). Ref. the old prank of jamming a potato over the tailpipe, blocking
> exhaust gases. Mice made nest inside air filter housing/high vacuum
> sucking/shifting debris and blocking airflow . Somehow this smacks of a
> heat-soak issue. (You didn't mention how long you were at dinner, or the
> ambient temperature) Possible inlet manifold gasket leakage. ("Sniff"
> around the manifold with a 2-3'-ft. section of smallish hose, 1 end in your
> ear, with engine running) Is there sufficient dampening oil in the dashpot
> of the carb? There's a bit to chew on.
>
> Charles Kellogg
> Director of Restorations
> Dare Britannia, Ltd.
> net.org/mailman/listinfo/rovernet_rovernet.org