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Pros and cons of running closed loop idle???? I think most systems are set to run open loop, but why? Any advantage or running closed loop?
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Ethan Brady
1987 Grand Wagoneer, slightly longer than stock.
www.bigscaryjeep.com
Don't mess with me. I once killed a living hinge. -
Actually most newer engines designed for EFI are closed loop idle.
The older engines like the IH and the AMC seem to like a little more fuel then 14.7:1 for a smooth idle.
So I normally tune for about a 124-126 BLM and once tuned I go to an open loop idle.
This gives a nice steady idle without the lean "roll" that can occur when in closed loop.
If you have a cam with overlap then open loop will be required to maintain a steady idle.
The raw fuel dumped into the exhaust confuses the feedback loop.Bill USN-1
Fuel Injection Moderator at BinderPlanet
Hamilton Fuel Injection
75 scout XLC 345/727/JPD300/3.73's/33's/4wdisc/hydroboost/EFI/OBA/OBW
1977 Innocenti 1001 (Italian Mini)EFI 1275/DIS -
My idle is closed loop, it was that way stock in the bin I am using. It seems to idle just fine. I think my old 7747 was closed loop idle too.
Mabey one day I will play with that setting and see if it changes anything. I know my idle got a better when I swapped to the 7427 pcm.79 Cherokee Chief 401/T18/D20, MPFI fuel injection, hydroboost, otherwise stock.
Future mods: Caddy 500/NV4500/NP205, HP D60 front D60 smooth botom rear, 5.13 gears, 35x12.50's on H1 beadlock wheels. Warn M12000 winch.
93 Wrangler 4.6 stroker/AX15/NP231,SYE,CV, OME 2.5 lift, front hub conversion/big brakes, 31X10.50's Warn M10000 winch.Comment
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