I adjusted the AFC and

[Steve Graham]

lost all power on the 4BT. I've done this on my Dodge and every thing came out great, more power on the bottom end. So I figured why not do the 4BT in the Scout. I pulled the top off the AFC, marked the diaphragm location and then pulled the diaphragm out and checked where the ecentric cone was in relation to the pin. It was almost at the full power setting so I just reinstalled the diaphram in its original setting and put the top back on. The engine will hardly rev now when the throttle is pulled open. So I took the top off again checked the marks, every thing was OK and put it back together. NO power. Took the top off again and again (several times)tried a different rotation(s), same results. I even took the screw adjustment off the top and check for full up and down movement of the diaphram, works good. Still no power. I then took the top of the AFC off again and reassemblied it minus the large return spring that sets under the diaphragm, still no power. Any one got any ideas?



Steve

 

[JFitzgerald]

I'm no expert, but... when I tweaked mine, and took it for a trial run, it made no difference. Drove it 25 miles, and no difference. Then when I drove it the next time, the extra power showed up. WOW! The only thing I could think of was that the horizontal pin that rides on the eccentric was sticking in it's bore, because I didn't touch anything after the initial adjustment.



Maybe open 'er up again and see that the pin moves freely and lube it if necessary.



May not be your problem, but it came to mind. Hope it helps.

 

[Steve Graham]

Yes I think your right, that the horizontal pin is probably sticking. I'll blast it with some PB or WD40 and maybe it'll break free by its self. Other wise its $$$$$$$$$$$$.



Steve

 

[Steve Graham]

The Fix

There is a screw with a 5mm allen head socket that holds the plunger in. I removed this and the plunger was inside, stuck. The back of the plunger has a half moon or "D" shape attached to it. This was contacting the threads of the screw and holding the punger in. I unfroze it and it slid back and forth like it should, but when I pushed it back inside so I could install the diaphram the plunger stuck again! So I installed the diaphram, unstuck the plunger, buttoned every thing back up and the Scout is running again, a little bit better.



Steve