[urq] Continued Fuel System Woes - Thoughts Appreciated

[Jon Archibald]

Hey all,
Patient is '85 3B transplant.
After installing my new fuel pump (Bosch 69430) the car seemed to run great
for a day or two, then one morning after some spirited evening driving with
my son I tried to accelerate onto the freeway and found power leveling off
at just a touch of boost. The ECU seemed to be limiting boost and timing,
and a glance at my Halmeter showed that things were leaning out under boost
whereas the mix usually gets noticeably rich.

I've disconnected various hoses to check if the pre-filter (sediment
canister) was clogged or if any lines seemed clogged to no avail. Fuel
poured out of the tank feed line smoothly and rapidly when disconnected,
likewise through the pre-filter. I cross-checked the part number on the
fuel pump and it appears correct for OE. I previously used a 944 pump the
PO put on, but I had read that a stock urq fuel pump will do just fine with
a tuned 3B. I also changed the fuel filter, no difference.

So at this point it seems the issue is either with the tank screen
(although again gas really came pouring out smoothly and quickly), or
potentially the pump. I really doubt the pump is responsible since it seems
correct for the car and I can barely get into boost as it sits.

I'm really hoping if it is crap in the tank that I can somehow get it
cleared out with the tank in the car, at least for the time being. I'll
probably open the tank access port on top and see if I can see anything
with a flashlight this weekend, possibly siphon some gas out and try to
pick up some debris in the process like when I clean fish tanks. I am
somewhat nervous about what can be accomplished with the tank in the car,
both in terms of visibility through the small opening and what unclogging
might be possible.

Any ideas/BTDT appreciated, thank you!
-Jon