Maxed out fuel screw

[rembrant88]

Quick question. I have the allen screw on my pump just about maxed out in prep for forced air, but it's going to take some time this summer to get parts machined and that system worked out right. In the meantime I need to get my bronco back on the road next week to pull my boat. I can't remember how far from stock position you turn the screw to max out, seems I'd have to go through a hundred fuel screw threads just to find the answer. And here I am making another one, lol. Can anyone remember? I thought it was something like half a full rotation but I may be way off. Thanks.

 

[lindstromjd]

As far as I recall, there is no such thing as a "stock position". Every single pump was calibrated from the factory to put out a certain amount of fuel, regardless of where the fuel screw sat to make that happen. If there was such a thing, then everyone could be told exactly how much to turn the screw out or in for a certain EGT, rather than the go-one-flat-at-a-time method.

... I for one don't understand why you'd touch your IP before you had the entire project ready to go. That's like salting your steak while it's still on the cow. You should probably just get a pyro and do the one-flat-at-a-time method backwards until you're back where you need to be.

 

[rembrant88]

As far as I recall, there is no such thing as a "stock position". Every single pump was calibrated from the factory to put out a certain amount of fuel, regardless of where the fuel screw sat to make that happen. If there was such a thing, then everyone could be told exactly how much to turn the screw out or in for a certain EGT, rather than the go-one-flat-at-a-time method.

... I for one don't understand why you'd touch your IP before you had the entire project ready to go. That's like salting your steak while it's still on the cow. You should probably just get a pyro and do the one-flat-at-a-time method backwards until you're back where you need to be.

Thanks for the reply. Yeah I know, I decided to side mount the supercharger and not worry about adapting it to the intake but changed my mind. To do it right always takes more time. Then again I didn't think my daily driver would fall apart either. This is the second time I've had to put my bronco back together instead of completing it as planned.

I never thought to hard about it, I just figured that each injection pump being off the same stock NA series of engines, being completely mechanical, would be set at approximately the same fuel output. I can see how EGT's would be more inconsistent when factoring in boost, but not with a NA motor. But you're right. The fuel adjustment is sensitive enough that it would be smart to base adjustment off the pyro regardless. I just thought if there was an estimate of maxed out rotation then I could get it close enough to bring the number of adjustment times down to a minimum, maybe even get lucky and have it within reason the first time. I would prefer to dump fuel out of that pump as few times as possible but whatever needs done shall be done.

 

[redneckaggie]

Just keep your foot out of it egts are conrolled by your right foot, the only thing that turning it down does is limits your max, but the same effect can be had by not burying the skinny pedal and watching the pyro. I am na and up abuout 4 flats and regularly tow loads, with 24 foot loaded down with cows it gets hairy, but just normal empty driving I REALLY have to flog on it to get near unsafe