WOT too Lean

[fastd]

Lippy,

Will try to lean the idle up a bit.

Gaz64,

It doesn't flat spot; it just gets lean. I do have the hollow squirter screw for my 42 in the back.

I've heard that the 850 xp is lean out of the box also.

I rehooked up my vacuum gauge and paid a lot more attention to it.

It's interesting how it moves when the engine is warming up as compared to when it is warm. To warm it up, it's easy to get the vacuum down to 6.5-5.5; that caused problems with my 7.5 - and when I used the high flow 7.5 it just drowned itself.

Anyway, I think the spike has more to do with WOT leaness than accelerator pump.

Gonna try a high flow PV but get like a 4.5 and 3.5 (instead of the 7.5). If the high flow is too much, might bring the PVCR down from 73 to 70, 67, or so.

[Gaz64]

Originally Posted by fastd

Lippy,

Will try to lean the idle up a bit.

Gaz64,

It doesn't flat spot; it just gets lean. I do have the hollow squirter screw for my 42 in the back.

I've heard that the 850 xp is lean out of the box also.

I rehooked up my vacuum gauge and paid a lot more attention to it.

It's interesting how it moves when the engine is warming up as compared to when it is warm. To warm it up, it's easy to get the vacuum down to 6.5-5.5; that caused problems with my 7.5 - and when I used the high flow 7.5 it just drowned itself.

Anyway, I think the spike has more to do with WOT leaness than accelerator pump.

Gonna try a high flow PV but get like a 4.5 and 3.5 (instead of the 7.5). If the high flow is too much, might bring the PVCR down from 73 to 70, 67, or so.

If you have WOT lean condition, I can't see why you want to reduce the size of your PVCRs.

Even a standard Holley picturewindow PV outflows PVCRs of about .090.

I think a lot of your troubles stem from the factory calibration of the 850 XP.

I'd love to know what engine Holley had it on when they did the calibration.

Gary