[urq] Subject: Better fuel pump needed

[urquattro at comcast.net]

I have a 944t fuel pump on my motronic 20vt , which the previous owner installed in the process of trying to solve a fuel starvation issue, which I believe ultimately ended up being caused by the notorious "clogged pickup plumbing" in the tank. Anyway, the 944t unit seems to work great and the plumbing looked like it was easy. The -bad- smoking problem I previous attributed to the bigger fuel pump turned out to be solved when I improved my vacuum plumbing for my brakes.

My car still smokes intermittently at idle before the O2 sensor gets warmed up, which says to me that fuel pressure creeps a little at idle due to the extra pumping volume, but with a programmable fuel system you should be able to compensate by adjusting your "open loop" injector pulse settings. My issue might just be a "pinched" modified FPR, which I've heard also can cause return flow issues and pressure creep anyway unrelated to the pump. I never tracked the problem down completely, just well enough to get through emissions, so I can't say.

Hope this helps - an option to consider, at least.

<<Turns out one of the problems I?ve had with my Megasuirt EFI installation and 
tuning has
been a crappy fuel pump.  It limits flow and the engine was running crappy at 5k 
and now
is cutting out at lower RPM and even idle too ? buzzing is very load.   Now this 
is the
third or fourth pump I?ve installed in this car.  The first pump was totally 
seized from
setting when I got the car about 5 years ago.  I purged the lines and flushed 
the tank
and installed a pre-filter.  I installed an 87.5 Coupe GT/Model 90 pump ? higher 
flow
and pressure.  The first one was defective out of the box.  The second one is 
now acting
up.  Tank was just flushed and I routinely replace the pre-filters even though 
they look
clean, so I don?t think any garbage is getting into the pump.  

So I am looking for recommendations for the best pump to use since I no longer 
have CIS.
I would be nice to have the output fitting mate with the stock fitting, but 
mainly I
want a reliable high output and pressure pump.  The inlet is already using a 
larger
hose.  I?m tired of doing jobs 2 and 3 times, so this time I won?t try to skimp 
on cost,
although the ones I?ve been putting in a Bosch Replacements.

Recommendations?

Ben>>