What to do for fueling, acf and plate or lack there of?

slrrls

slrrls

Water fuel 1st diesel 2nd
Joined
Jun 30, 2012
Messages
135
http://www.competitiondiesel.com/forums/images/smilies/welcome.gifIt's sometimes hard to sit down and type out a situation and ask questions with out sounding stupid at some point and sometimes all points, so just let me know if something don't make no sense.
swapped out the 24 valve and been running the stock 12 valve bout 5 years.
Too many projects later and I'm tending to a few issues I put on the back burner 5 years ago.
Never modded or been into the AFC or Plate area in any diesel before.
Following a favorite thread on AFC mod I am now on this matter and have some questions.
When I got the motor the guy said the only mod he had done was the killer dowell and turned the star wheel up a little.
I read up on the AFC tuning and I started with replacing the Big body washer for the stock washer under the diaphragm. Then I removed between 1/16 to 1/8th of the rack travel. I cut off around 1/8th of the AFC foot.
I think I may have ended up taking offan extra 1/8th because someone had already done this. So my measurement is total 5/8ths of the metal now existing.
Watching it under pressure I kind of think it would not matter if the rack is now 1/8th too short but it would be nice to know.
(Q) Is this (5/8th) the correct size? because when I apply 40 psi the rack travel moves the rack to the back but leaves 1/8th of empty space between the end of travel and the rack.
I bumped on to my first hint here that the motor had been moded on the ACF already.
I didn't see it at that point really it was the next step where I adjust the star wheel.
I went on to adjusting the smoke screw.
The way I read the thread is that from the inside of the cup where the diaphragm of the screw is adjusted so it is flush with the inside of the cup then that is all the way out and if it is screwed into the the inside of the cup and 1/8 or so then it is all the way in.
Well mine was an inny.
So I realized that taking into the account that the cut off safety screws revealed someone had been in the afc to begin with and now I see the extent of the Modding done already. AND I gandered the fuel plate to see what I'll need to do and the fuel plate aint there!
When I put 40lbs psi to the boost line entry then the rack travels all the way back. At 20 lbs psi the rack travels to about 1/2 way just like it should per the pictures in the Mod thread I mentioned.
Honestly, I have not seen 40 lbs boost on the boost gage yet. I see around 20 and that is just running up and down the road out front getting up to about 55mph
on to the issue.
When there is no air pressure applied to the afc then the foot rest just as in the pictures which is about right up against the diaphragm cup wall..
When no psi applied the star wheel is all the way to the side and just about out of view looking in the window.
So I have another question.
(Q), I have a stock 35 turbo so If I want the fueling to come on and I only have 20 psi on the boost then shouldn't I turn back the star wheel to about the middle of the window and set it up so the fueling will come on at around the 20's psi mark?

To sum it up there are really 3 questions.
the one directly above and:
(Q) Is this (5/8th) the correct size? because when I apply 40 psi the rack travel moves the rack to the back but leaves 1/8th of empty space between the end of travel and the rack.
(Q)with a modded AFC would the star wheel normally be just about out of site in the direction of the motor when the afc is mounted? or would it be normally somewhere in the middle on a stock motor?http://www.competitiondiesel.com/forums/images/smilies/nopic.gif
 
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thanks for the quick reply, I can reassemble now.

Since there is no fuel plate I read in one thread that running with no fuel plate can damage a pin inside that does alot of damage.
I read another that said a fuel plate is only for limiting fuel.
Do I need to get a fuel plate in soon or does the damage only affect built up drag motors?
 
No damage will occur to the pump from removing the fuel plate permanently. Pistons melting however could be possible.:Cheer:
 
:chug::chug::chug::chug::chug::chug:http://www.competitiondiesel.com/forums/images/smilies/gr_chug.gif

I did add egt and boost guages this past week so I can stay away from high temps. never got above 1125F. To think I drove for 5 years not knowing about the mods already done, sheesh.

I replaced the lift pump, cleaned nasty prefilter and replaced the main fuel filter this past week, man did it come alive! Thing was starved for fuel.

I'm going to start work on a hydrogen maker now for the tdi the mercedes and the cummins. hope to kick up mileage 25 to 30 percent.
Maybe time for number 10 plate and an AFC live now.
 
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I wouldn't worry about even 1400° egt, just don't keep it up there for more than 20 seconds at a time. Short burst.
 
No damage will be done from running no plate, been running all mine that way for years. The stock AFC spring will coil bind and not let it reach full travel, people have used the big spring from there stock governor springs as a replacement if you still have those. I found an inner valve spring from a set of aftermarket BBC springs work well, I cut it down to the correct length from trial an error until its right. You can also run a light spring and control it by running a regulator to control it that way (AFC live would be the easiest).
 
Is the afc live just a valve placed in the boost line running to the afc?
Has anyone back engineered it? I searched but no hits.
 
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It looks like two regulators, one controlling max travel and one controlling the rate it gets there. I believe they also include a spring with the kit to match the set. You could make your own but theirs is proven and a nice clean set up. Dont know what it cost though. I've used a spring that was to light with an inline reg and it worked good, not near the adjustment level of AFC live though, I'd like to try theirs sometime.
 
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