2f Carb Tuning - Timing - and Vacuum Routing for Desmog (8 Viewers)

[dannyvp]

I also adjusted the distributor. I rotated it around .250” counter clockwise to raise the vacuum. It can not rotate anymore to the left.

 

[dannyvp]

Theres a guy in MN who recurves that I recently chose to go with for a spare I had... I can't try it yet because my engine is out but he was very reasonably priced and quick and easy to communicate with, @distributorguy, his name is Jeff.

I spoke to him, what a nice guy. I have a few things to try this afternoon to see if it helps.

 

[dannyvp]

I advanced my timing to 16 deg according to jeff at advanced distributer, unfortunately it didn't change anything. I still have the same problem.
My vacuum has increased. Im running 15 to 16 vacuum.

 

[Seth S]

Maybe you said it already....but have you done a compression check?

 

[dannyvp]

Maybe you said it already....but have you done a compression check?

I have not. I don't really know how.

 

[NeverGiveUpYota]

I have not. I don't really know how.

Don’t. It’ll bring you down the rabbit hole.

 

[dannyvp]

Don’t. It’ll bring you down the rabbit hole.

Too late. Doing it now.

 

[dannyvp]

1- 160
2-155
3-160
4-150
5-160
6-160

 

[NeverGiveUpYota]

1- 160
2-155
3-160
4-150
5-160
6-160

Not bad. Let it ride. Get the valves in place and see how it is after that.

 

[dannyvp]

Not bad. Let it ride. Get the valves in place and see how it is after that.

valves are in, problem is the same.

 

[cheeese]

Joining in realtime since it looks like there are a few of us messing with this right now - let me know if I need to split off to a different thread. I just did the FSM lean drop method on my desmogged 2F with factory carb after plugging a big vac leak, got a steady idle at ~650 rpm but only 16" vacuum. No black smoke, maybe a little grey smoke (which could have been residual from the initial part of the process). Exhaust doesn't smell rich anymore.

My notes and questions:
- Initial few 1/2 turns had a lot of effect raising the idle as shown in the OTRAMM video. Once I brought it back down to ~700 with the idle speed adjust screw the effect of the idle mix screw was less.
- After hitting the mixture-speed plateau, turning it back in any more than 1/4" turn started to sound rough. 1/4" turn in from plateau seemed to be the sweet spot.
- Initial vacuum was 13-14" and wouldn't climb above 16". Should I advance the timing per the chart g-man posted? I didn't adjust the timing which was previously set by a local Cruiser guru, my understanding is a little too retarded is better than risking detonation with too much advance.
- Without an O2 sensor, what's the best way to know if the idle AFR is correct?

 

[dannyvp]

- Initial few 1/2 turns had a lot of effect raising the idle as shown in the OTRAMM video. Once I brought it back down to ~700 with the idle speed adjust screw the effect of the idle mix screw was less.

I have almost no increase of rpm's. How is your vacuum hosing ran? Post some pics.

 

[cheeese]

I have evap and charcoal canister as well as the driver's side VCV. VTVs on both the carb and distributor are present. The outer vac line on the distributor advance runs to the air cleaner. Sorry the wiring is messy from a desmog I didn't do, but it ran well albeit tuned to compensate for the vac leak.

 

[g-man]

sorry meant charcoal canister. not vacuum

 

[g-man]

Valves have been done, truck does not run hot.

Yes the valves were installed but after the head was put on the truck were the valves adjusted? Here is a guide to adjusting the valves. Put the TDC line on the flywheel to the top pointer, then with the rotor pointed between the 3 and 4 plug holes you will have piston #1 at TDC then adjust the "a"s and then the "b" valves in the chart below. Next move the flywheel around again and put the TDC line to the pointer, this time the rotor will be pointing away from the motor. now adjust c and then d. The 1st column is the rocker you are working on starting at the front of the head. The second column is whether it is an exhaust or intake valve. 3rd column is what you adjust to if your engine was warmed up first. You'll need a feeler gauge and a 12 mm box wrench and a screw driver. Before you start, make sure the rocker rail studs are all the way seated in the head by backing off the nuts and doubling up 2 nuts and tighten them against each other on the stud threads. Then use the top nut to turn the stud to make sure it's seated in the head.

 

[dannyvp]

Yes the valves were installed but after the head was put on the truck were the valves adjusted? Here is a guide to adjusting the valves. Put the TDC line on the flywheel to the top pointer, then with the rotor pointed between the 3 and 4 plug holes you will have piston #1 at TDC then adjust the "a"s and then the "b" valves in the chart below. Next move the flywheel around again and put the TDC line to the pointer, this time the rotor will be pointing away from the motor. now adjust c and then d. The 1st column is the rocker you are working on starting at the front of the head. The second column is whether it is an exhaust or intake valve. 3rd column is what you adjust to if your engine was warmed up first. You'll need a feeler gauge and a 12 mm box wrench and a screw driver. Before you start, make sure the rocker rail studs are all the way seated in the head by backing off the nuts and doubling up 2 nuts and tighten them against each other on the stud threads. Then use the top nut to turn the stud to make sure it's seated in the head.

View attachment 2039732

Yes sir, I did that.

 

[g-man]

what other open pipes or hoses to you see?

what did you hook the secondary vacuum port on your dizzy vacuum advance to? Looks like the metal vacuum lines have been removed.

what is that yellow foam looking stuff on the pcv hose where it goes into the elbow on the intake below the carb?

are you sure your hitting on all 6 cylinders...ie you don't have a bad plug wire etc.

 

[dannyvp]

what other open pipes or hoses to you see?

There's several open "items" under the hood. Most are probably fluid hoses, i would have to check when i get back to the house.

what did you hook the secondary vacuum port on your dizzy vacuum advance to? Looks like the metal vacuum lines have been removed.

No where, The instructions i saw said leave it open.

what is that yellow foam looking stuff on the pcv hose where it goes into the elbow on the intake below the carb?

That foam stuff is just from the fitting i used.

are you sure your hitting on all 6 cylinders...ie you don't have a bad plug wire etc.

I'm running ruff, for sure. I have new Toyota plug's and wires that i haven't installed yet. The wires installed are only a month old though, they are just $20 wires. (i was just waiting to install them once i was running better)

 

[g-man]

Pull each plug one at a time, put the plug wire back on it and hold it in a pair of pliers with rubber handles and look for spark jump between the gap while cranking (but not running) the motor. Double check your firing order. Install the new plugs and wires ...test running it isn't going to fowl them that quickly.

 

[g-man]

Any open ports or hoses that your not sure about, spray just a little carb cleaner or starter fluid or post images here.