More Questions on fueling

[LS1_Dragster]

454 with 0411 computer and 01270003 OS.

I've got the semi-closed loop working but with my setup 14.63 at idle and crusining is just too lean so if I change B3601 to something like 14.20 then change B3647 to 14.20 in those areas I want to use semi-closed loop then it should work fine - correct?

Also, when it's cold I change A0008 to 1.20 at 50 degrees and so on so this will change the commanded AFR at those temps but I can never get the commanded AFR to match the Wideband AFR when it's in this mode. Once A0008 goes to zero and warmed up the AFR's are near perfect. So what's stopping me from making the cold AFR's to match?

Lee

[The Alchemist]

depending on the problem you have, as you have haven't actually said why 14.63 is too lean,,,, do you have a lean hunt at 14.63?
If this is the case you can work around this by raising the O2 switch point to around 480 to 500mV this raises the "lean switch point" slightly often enough to eliminate the lean hunt. 14.64 might become 14.4 for example. Also at light thottle with a lean mixture a couple degs extra timing just at that point can often improve things.
MIke

[dfe1]

depending on the problem you have, as you have haven't actually said why 14.63 is too lean,,,, do you have a lean hunt at 14.63?
MIke

I suspect 14.63 is too lean because the engine has a bunch of camshaft and about as much fuel goes out past the exhaust valve as stays in the cylinders.

What AFRs are you trying to achieve with A0008? What are you expecting for commanded ratios? Keep in mind that a lot of multiplication factors are easier to work with if you use EQ ratio instead of AFR.

[ringram]

TPS fueling might be the friend you need to make aquantance with. The COS will sort that out for you.

[johnv]

454 with 0411 computer and 01270003 OS.

I've got the semi-closed loop working but with my setup 14.63 at idle and crusining is just too lean so if I change B3601 to something like 14.20 then change B3647 to 14.20 in those areas I want to use semi-closed loop then it should work fine - correct?

Also, when it's cold I change A0008 to 1.20 at 50 degrees and so on so this will change the commanded AFR at those temps but I can never get the commanded AFR to match the Wideband AFR when it's in this mode. Once A0008 goes to zero and warmed up the AFR's are near perfect. So what's stopping me from making the cold AFR's to match?

Lee

Don't touch B3601

Just use the Bi Directional controls to determine what AFR your combo likes at idle, then command that at the desired rpm and load pionts in B3647.

You will need to do the auto VE to ensure your VE table is dialed in so actual AFR is the same as Commanded AFR.

[LS1_Dragster]

Don't touch B3601

Just use the Bi Directional controls to determine what AFR your combo likes at idle, then command that at the desired rpm and load pionts in B3647.

You will need to do the auto VE to ensure your VE table is dialed in so actual AFR is the same as Commanded AFR.

But wouldnt I loose closed loop? My understanding is that whatever you set B3601 to and matching values in B3647 is the only time you will get closed loop.

So if I set B3601 to 14.10 and the cells in B3647 to 14.10 at idle and cruise I would achieve closed loop only in those areas.

I'm just trying to use the computer as much as I can at idle and cruising, if this is not possible then I will stick with open loop all the time and be done.

Also, I've done the auto VE procedure.

Lee