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AFM744 AFM744 is offline
Cynical Misanthrope
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Join Date: Dec 2001
Location: Campbell, CA
Posts: 382
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Once I drew this out in complete diagram it came to me. The manifold diaphram center has a smaller concentric spring and a threaded preload adjustment for that spring seat. Initial conclusion was this threaded adjustment would preload the manifold pressure enrichment ...uh, the other way. Once I looked at the drawing and saw that this adjustment also carries the spring pressure from the bottom main spring I realized I've successfully raised my manifold pressure enrichment diaphram (rather than lowered it) thus why my control pressure is stupid-low, and why I'm getting single digit A/F ratio on boost.
But I had to completely disassemble this thing and draw it out in 2D with fuel pressure vs spring vs diaphram loads to SEE how this relic works.

Now to start ordering more EFI parts...

EDIT: Yes I could've just sent the bloody thing to Brian Leask, a saviour for these cars. But I'm the kinda person who *might* ask for help when, but not before I need a coronary bypass. I concede that I can't do that myself.
X-1, AFM744, Jon, '92 C2 Turbo
JE 8:1 pistons, 964 cams, 38mm intakes ported/polished/twinplugged, ARP hardware, B&B headers/exhaust, 355whp. Full-blown GT35R 3.2 intake EFI pending...
Where my misspent time and money is currently going.

Last edited by AFM744; 06-18-2008 at 11:12 AM..
Old 06-18-2008, 10:52 AM
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