2f Carb Tuning - Timing - and Vacuum Routing for Desmog (1 Viewer)

[g-man]

Of course ...being de-smogged and having a non US carb, things may have gotten moved around.
you should still be able to keep both the canister system and HAC system if you need it.

 

[g-man]

Reading back thru this thread looks like you are tuning a fuji carb and can't get things right.
Did you set your upper and lower idle speeds? You should have screws for that.
The fuel/air mix screw should come preset at the factory. I'd hold off and touching that one for now.
You said when you choke it ...the truck stalls? You'll need to set the choke.

 

[g-man]

That is the pcv hose from the base of the carb insulator. It SHOULD go to a valve called the positive crankcase valve which hooks into the hard J pipe that sticks out of the side cover of the block on the passenger side of the engine.

Noooo. Fel ...its coming out of the firewall. Pretty sure its a vacuum line that hooks to the top of the stock carb and is for the canister. But he doesn't have it hooked up ..other end is prob open too.

 

[dannyvp]

New video. One hose fixed.

 

[dannyvp]

Drivers Side

 

[NeverGiveUpYota]

Noooo. Fel ...its coming out of the firewall. Pretty sure its a vacuum line that hooks to the top of the stock carb and is for the canister. But he doesn't have it hooked up ..other end is prob open too.

My mistake. I deleted it not to add any confusion.

 

[g-man]

The vacuum line on the outer dizzy vacuum advance port is an secondary vacuum advance and is put in service when the HAC high altitude compensator is activated. Since you removed the HAC you can just take that hose off an plug the secondary port. But if you want to know where it goes,...up and behind the t-stat is a small VCV on the metal vacuum lines. It goes to that metal line.

 

[dannyvp]

The vacuum line on the outer dizzy vacuum advance port is an secondary vacuum advance and is put in service when the HAC high altitude compensator is activated. Since you removed the HAC you can just take that hose off an plug the secondary port. But if you want to know where it goes,...up and behind the t-stat is a small VCV on the metal vacuum lines. It goes to that metal line.

I'll plug it.
FYI, I didn't do the desmog, it came this way. I did put the Fuji carb on though, bc mine leaked gas bad.
I'll plug that port and see what happens.

 

[dannyvp]

Video while tuning.

 

[g-man]

nothing is going to happen cause you removed the bvsv and the hac and no vacuum lines going to the air filter in front of the carb on the intake. So I would image no vacuum is coming off that metal line.

 

[dannyvp]

Reading back thru this thread looks like you are tuning a fuji carb and can't get things right.
Did you set your upper and lower idle speeds? You should have screws for that.
The fuel/air mix screw should come preset at the factory. I'd hold off and touching that one for now.
You said when you choke it ...the truck stalls? You'll need to set the choke.

So when I tune with the lean drop method, the tuning does not work correct. When you adjust the fuel air screw, it should increase the RPM, mine is lessing the RPM.

 

[dannyvp]

nothing is going to happen cause you removed the bvsv and the hac and no vacuum lines going to the air filter in front of the carb on the intake. So I would image no vacuum is coming off that metal line.

The little metal line with the red cap is pulling a big vacuum. I just don't know if a line runs to it. It came plugged.
If you unplug the red cap, the vacuum goes from around 12 to 15.

 

[Seth S]

So if you keep turning the idle screw in (CW) does the rpm keep rising?

 

[g-man]

That line with the red cap is basically an intake vacuum port. I don't think you want to hook the canister line coming off the firewall to it because the original one is going to a port up high on the carb...probably means it should draw more during acceleration and not hard vacuum all the time.

 

[dannyvp]

So if you keep turning the idle screw in (CW) does the rpm keep rising?

Yes, it will rise all the way to where it is sitting flush. But that may only be 800 rpms.

 

[g-man]

what other work was done besides the carb? Was the truck running good before pulling off the old carb? the reason I ask is I am wondering if the timing is off or the valves need adjusting. Have you been able to drive it with the new carb? Is it running hot?

 

[dannyvp]

what other work was done besides the carb? Was the truck running good before pulling off the old carb? the reason I ask is I am wondering if the timing is off or the valves need adjusting. Have you been able to drive it with the new carb? Is it running hot?

A new rebuilt head is on the truck, that's how I noticed the carb was having issues. The old carb ran, just leaked a lot of gas.
Valves have been done, truck does not run hot. I can drive it with the Fuji carb, it just smokes and smells bad.
I just adjusted the timing yesterday, while trouble shooting.

 

[g-man]

Choke plate not opening all the way when the choke lever is pushed back in? It should be straight up and down.

 

[dannyvp]

Choke plate not opening all the way when the choke lever is pushed back in? It should be straight up and down.

I don't even adjust the choke to start it.

 

[dannyvp]