View Full Version : FJ40 timing question

02-14-2009, 01:08 PM
I'm helping Dan (MtnGoat) out with a carb rebuild on his FJ40. We're going to do a tune up on it while we're at it. I have a question regarding the timing. He has a desmogged '74 2F that came with a vacuum retard distributor. It was incorrectly connected to full vacuum on his carb base. We were going to block off the vacuum to the distributor and just set the timing. I have a vacuum advance distributor on my 40 and have never timed a 2f that had a vacuum retard distributor. Any tips on what to set the timing to on this one? Thanks!


02-14-2009, 05:23 PM
Minor correction: my motor is a 74 F155 rather than a 2F. And thanks to Martin I'm going to have a rebuilt carb soon!

My truck drives pretty good but it has a gnarly rough idle that I'm hoping the rebuilt carb will fix. I also ordered plugs, wires, points, dist cap & rotor, a thermostat & gaskets and an air filter from CDan that shipped Friday. We'll replace the fuel filter too, but I am getting a clear one from Napa so I can see if I'm pulling crap from the 42 year old tank.

I already replaced the goobered up PCV valve that was stuck. That helped a tiny bit. :hill:

Air Randy
02-15-2009, 07:22 PM
I cant help you with the vacuum retard info since I replaced the stock distributor in my 74 F155 with an HEI unit. I run 20 degrees static advance on that unit and it seems to run pretty good.

If you need any stock distributor or coil stuff let me know, you can have any of this stuff I have laying around.

02-16-2009, 12:24 PM
Thanks Randy! Any chance you have a spare 69-74 aisin 2 barrel you can spare? Dan's carb is missing some linkage and the choke breaker.

Dan, made some progress. Kim even let me bring the carb inside the house to assemble since it was so cold in the garage. ;) :bowdown::Princess:


I have it all cleaned and reassembled. New gaskets, jets, accelerator pump, and float valve. Set the float height and am working on the linkage.

In this pic I put arrows showing where we have issues. The top arrow shows where someone has welded the choke linkage. Second is where one of the missing choke breaker/TP linkages should attach. Third points to the lower throttle body linkage/mechanism which is different than what you have on your current carb. We'll need to brainstorm a way to connect that throttle cable. On your current carb, I think it is wrong and limiting your mechanical secondary from opening.


We might have to pull a couple of pieces off your other carb to connect that throttle cable. I wish we had the choke breaker and linkage too because it's going to cause issues with that high-speed idle mechanism flopping around.

Anyone else have a spare carb we could get parts from?

02-16-2009, 12:44 PM
Dang Martin. That carb is purty! :cool: You :headbang: dude. Hopefully someone will pipe up so we don't end up with a Frankenlinkage. :hill:

But, if we need parts off the old one it's okay. I am hating that neither one is actually complete.

Air Randy
02-16-2009, 12:46 PM
Sorry, no spare carb stuff just the distributor and coil

02-16-2009, 05:53 PM
Anyone else have a spare carb we could get parts from?

I have a couple spares of the proper vintage.

In timing without a proper vacuum advance carb/dist setup, just leave the dist vacuum diaphragm unconnected and plug of any vacuum ports on the carb. At least until the proper carb and dist can e procured. The set the static advance where it runs best. My guess would be somewhere between 13-18 total static BTDC.

02-17-2009, 04:02 PM
Thanks Jeff!