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Old 12-01-2012, 12:13 PM   #1
Scooby Newbie
Member#: 73330
Join Date: Oct 2004
Chapter/Region: International
Location: England
1998 Legacy BH9
Deep Red

Default Running lean at WOT/5000+rpm

Been running with my wideband lambda gauge for a little while now. Noticed, and accounted for with an SAFC, that above 4000rpm the AFR got richer and richer - linearly. I also noticed that I was losing manifold pressure (albeit gaining vacuum) as the revs went up at WOT.

Bing, light bulb illuminated, I've never changed the airfilter! Stripped her out and replaced with a clean K&N.

Fired the beast up and went for a spin, now, the moment I go over 5000rpm (WOT) the lambda gauge goes leaner than a lean thing and will only display " - - - " (which maybe means that it is somewhere beyond 18:1).

I even spruced the old SAFC up to +30%, but to no avail.

This is a JECS MAP ECU, circa 1998, which surely is running speed * density rather than alpha n? Would it not see a completely filled plenum now and fuel up? Maybe my fuel filter is in just as much a need of a replacement.
Is it common practise to change the fpr for an adjustable fuel pressure regulator? Or do people swap the NA injectors for turbo injectors?

I have rebuilt the engine, forgive me for my hazy memory but I have 7 different cars all of which with different specs and I forget what is what - and the beer doesn't help the memory either.
7 degrees later IVC
11:5 comp
phenolic TB spacer - 1"
phenolic manifold spacer - 1/4"
no TB heater pipe
ported heads
tubular manifold 32" pri 1-1/4", 60" total 1-5/8", 4-2-1 Equal length
2" exhaust system, single 2" cat, single straight through silencer
balanced bottom end
8kg flywheel and lightweight under pulley
earth strap mod

Any tips on how to get more fuel in very welcome,
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