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mark houghton mark houghton is online now
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Join Date: Jul 2008
Location: Central Washington State
Posts: 4,435
Quote:
Originally Posted by JFairman View Post
Hi Mark, the mixture screw is not going to do it.

lowering the bottom differential chamber pressure with the pulse valve returning fuel to the tank lowers the diaphram in the fuel head which lets more fuel flow into the orifice in the top chamber and that richens the mixture.
you turn in the 6 seperate spring tension screws in the top of the fuel head to do the same thing mechanically and then leave it.
you have to do the injector flow test with 6 little bottles like has been posted here to do that accurately between all injectors.

to show the lambda box is not needed on an '86-'89 reach under the seat and unplug the big multi pin prehistoric harness plug from it and you will see that the motor runs just the same without it...

only unplugging the oxygen sensor may work well enough on your car and is simpler if you think the AFR's are acceptable at high rpms and boost so just leave it that way if that works good.
Cool. I've been meaning to flow check (and adjust if needed) the injectors anyway, so this would give me a good excuse to rip out the lambda box entirely.
Or just leave it to your point; my car runs well and AFR's are where they need to be with just the O2 unplugged. I just don't like the idea of waiting for the freq valve to eventually die and would rather have it out of there entirely.

And oh....this would also entise me to remove the front seat and go after that damn speed rev limiter relay which I believe is starting to give me sporadic fuel pump running issues.
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Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, B&B intercooler, stock 3LDZ.
Old 02-24-2011, 12:53 PM
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