I think the paint thinner destroyed the walbro pump.
Not sure yet. Thinner is squirting out the relief hole
on the top of the pump.

Paul Lamar
Your friend is quite a joker.  He's probably laughing his head off.
  "This will fix Paul!"
Mark Waldron
Probably but can anybody tell me what is wrong? Hint.. take a look
  at the plumbing picture I up loaded.
Paul Lamar

The valve on top of Walbro GSS 341s ("255lph high pressure") can be a
bit unreliable. Enough so that I'd be wary of using one for an
aircraft without disabling the valve somehow.

When I was trying to troubleshoot fuel starvation issues under boost
on a friend's car, we discovered this valve had failed. After plugging
it with epoxy, there haven't been any problems.

-Chris Wood

I agree with that. I am not happy with the one I have as the valve is popping off
all the time as I have only one injector on it right at the moment and
the injector is off most of the time. The other thing I don't like about it is the plastic
hose barb. Vinyl hose slips right off at over 60 psi no matter how tight the hose clamp.
I had to change the hose to rubber to keep it on. That is scary for aircraft
use. I have two Walbro type pumps and both have plastic barbs.

The pulse width modulated high pressure
pump is long over due but I am setting that project aside for another time.
In the mean time I am turning down the pump voltage just enough to maintain
fuel pressure. The other thing I have learned is that Aeromotive regulators are
leaking vacuum so bad I am unable to pump it down to less than 15 inches of Hg.
I have not put a condom on it yet as per Larry suggestion. I sure wish
I had one that does not leak.

I bought a better used pump from Klaus that Air Flow Research sells. It has
metal hose barbs and is much more robust. It looks a lot like an MSD
pump. It could in fact be an MSD pump. Tracy used to sell a pump but I don't see
it on his web site now.

The Ford Explorer looks pretty good with a metal hose barb.

BTW the paint thinner seems to have somewhat higher viscosity than
gasoline so I am not sure what affect that has on the pumps.
The RX8 injector deals with it well at 55 psi so far with a very fine
mist.

Paul Lamar

See http://www.rotaryaviation.com/fuel_pumps.htm for Tracy's offering.
I have a couple of used ones that were on my plane when last flown.  If
you want one of them, send me a mailing address.

Bob W.