Oops. Just realized I might have messed up...

[Idually]

Hey guys. In an effort to futher my knowledge on the CTD, I've been taking "baby steps" with things and getting familiar with what goes where and what it does. So... I pulled the cover from the AFC to take a peek. Mind you, I'm not trying to gain any more power at this stage. I completely forgot about the "offset" in the taper of the pin and did not mark where it was. Can someone tell me which direction the offset should be? I need get back in there and correct it. It's been running really well, but I noticed yesterday, when I "got on it" from a stop sign that it really was lacking power. It got me a bit concerned. I have a lot of things to check, because this loss of power seems to have come on rather suddenly and I was into AFC housing a few weeks ago. Not sure what to think, but correcting this leaves me one less thing to think about. I'll post more about the "power loss" soon.



Thanks in advance!

Andrew

 

[OKish]

on the taper there should be a spot where its worn from the fuel pin. just put the worn spot towards the front of the truck.

 

[Idually]

OKish. Thanks. Is the fuel control pin spring loaded? In other words, if I pull the eccentric pin up and out, will the fuel control pin stay in place?



Andrew

 

[Greenleaf]

A simple Baby step would be to message the afc with simple adjustments. You can reposition the star wheel and also the cone profile (in relation to the fueling pin). You may want to shave the white/yellow nylon "limiting" washer in half with sand paper. (to 1/2 thickness).



If you or a friend has a Dremel try changing the cone ramp (profile) to slightly more aggressive little by little. It will need to be a very smooth polished surface after your done cutting in each new profile. I finish off with a fine stone.

 

[Idually]

Thanks, GL. It must have been me yesterday or a fluke. I popped the top of the AFC, again, Pulled the pin and YUCK!!!! Lots of crud on the pin. Enough to affect "control" pin's movement and position. Sort of a waxy light brown crud. Can't be good. Cleaned the pin and Bore. Replaced it with the "cone" indexed to about 10:00 o'clock. Not much difference. Maybe a smidge.



While I was doing this I was thinking about this whole thing. I never really knew what was going on. Now I get it. I think it goes some thing like this.



The AFC seems to be the Brain of the pump. At idle, the AFC pin is up (due to the spring) so the fuel control pin is "shut" in it's bore. Off idle, the amount of boost controls the position of the AFC pin, which in-turn controls the position of the fuel control pin. Changing the "index" of the AFC pin affects how much fuel (at idle and off idle) is delivered. Pretty cool!! It's just a matter of where these things a "set". I can see, if you index the AFC pin too much you could be sending a bit too fuel too soon, making loads of smoke! Correct? Am I on the right track? Also, shaving the nylon "stop" washer and turning the star wheel, will allow the AFC pin further into it's bore allowing more fuel to be delivered along with the "boost" or air. So, I guess, depending on what you want, the AFC, could be set for a lots of different combinations? Make sense? I'm going to go play some more. The RC is isn't making hardly any smoke from a slow idle speed to 3/4 throttle.



Thanks guys!!!!

Andrew

 

[Idually]

Hey Guys! Had a little fun yesterday... I did a couple of minor things that seem to "wake up" the motor a bit. Star Wheel in 2 turns, Cone indexed to 10:00, Nylon "stop washer" shaved to half thickness. Just these things, brought the idle up a bit, but not too much, but I know why now! That is the best part. Still no smoke at idle, but just a bit on a medium hard launch from a stop.



Oh yeah. Can anyone get me an idea about the position that this full fuel screw is in. It was fully in, with the "lock" still in place. It is backed out a 1/2 turn, now. Just don't know where it was "stock".



#ad




#ad




Thanks again! I really enjoy learning this stuff and I can't think of a better place to learn it!



Andrew

 

[tugboatphil]

Andrew,



If I have read correctly, from previous posts, if the locking collar is still on, the screw is not "really" adjustable. What you might think is all the way in, would go even further if the collar were off. My truck didn't have one, so I am not sure.



They are apparently easy enough to get off, but were placed on by the factory to keep, ummmm... . guys like us from messing with the screw.

 

[Idually]

Thanks Phil. I wondered. I looked at my '93 yesterday. It has no lock collar either. So if that IS the case and I backed out a 1/2 turn(which I did), performance would go down a smidge, no? Just trying to confirm where this thing is at right now? At least I'd have a "base" to work with. I've posted this pic before, and Pastor Bob commented on it. He was going to send something about these pumps, that he thought I'd like to read, but I didn't get it. I never asked for it a second time, though. P. B. If you bump into this, could you send over the "pump thing" again?





Thanks again!

Andrew

 

[Idually]

Well... Ole Red (The CTD RC) is running awesome! Thanks Guys!! Now I need to get my '93 to run like it... Life is full of challenges... Again Thanks.



I'm curious about the fuel screw, no doubt. Any thoughts?



I put it back to where it was when I go the "donor" truck, so we'll see tomorrow.



Andrew