Injectors and Required Fuel

For discussing injector selection, manifold modifications, throttle bodies, fuel supply system design and construction, and FIdle valves and IACs.
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jayonator
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Joined: Sun Sep 18, 2005 9:51 pm
Location: AZ

Injectors and Required Fuel

Post by jayonator »

I'm having a tough time deciding what set up would work best for me. I have a 3.0l (183 inch) v6 with stock 17.9lb/hr @ 46psi injectors (port). I understand the benefits of alternating injections so initially I tried 2 squirts alternating but that gave a req fuel of 18.0ms. 6 squirts alternating gives me a 6.0ms req fuel. I know I could go simultaneous 2 squirts and have a 9.0 req fuel.

According to the manual the req fuel should be between 8 and 12/15 so... are the benefits of alternating injections worth getting slightly larger injectors that can alternate within the 8.0-12/15 range? Or would running simultaneous be just as good. Thanks for any input.
Minami Kotaro
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Location: Somewhere in TN

Post by Minami Kotaro »

Try each combination and go with what works best.
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Philip Lochner
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Joined: Thu Feb 16, 2006 5:18 am
Location: South Africa

Post by Philip Lochner »

Best is to stick to 2squirts / alternating. Don't stare yourself blind with Required fuel. The manual is a guideline - not a law - but it is a GOOD manual.

Get the engine started, and tune the VE table roughly. If its very "flat" (ie little difference between low kpa bins and high kpa bins for the same rpm), you can reduce the required fuel which will then "stretch" the VE table vertically and will allow you to tune more precisely.

See: http://www.msefi.com/viewtopic.php?t=21603&highlight=
and
http://www.msefi.com/viewtopic.php?t=20758&highlight=
Kind regards
Philip
Land Rover Discovery '95 4.6 V8i MS-2/V3/2.36/LC-1/EDIS
Jaguar XJS V.12 5.3, MS-2(2.686t11 - Dual table)/Dual LC-1/MSD6A/spark(VR/dissy)+fuel(LoZ+PWM)
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