2f Carb Tuning - Timing - and Vacuum Routing for Desmog (18 Viewers)

[g-man]

The main vacuum advance port on the dizzy needs to go to a carb advancer port. Disclaimer, I am not a Fuji carb technician.

 

[NeverGiveUpYota]

“The inner distributor spark advance diaphragm originally had a passive VTV inline with it. It's a plastic bidirectional valve that lets air flow easily but slowly the other direction.
All the VSVs are powered by 12 volts and the FCS. As well as the charcoal can outer vent control valve.
VTVs aren't triggered. They just restrict the air flow.
VSVs will open or shut if 12V is applied to them.
BVSV don't use power. When the temperature reaches a certain value its internal valve opens.”

 

[g-man]

In post #157 you have mwebfj60 diagram of connecting the VCV without charcoal and then the second image w/charcoal canister. That second image shows the VCV getting "T"d into the main vacuum advance line. I'm not sure how that affects vacuum advance on the dizzy if the VCV changes vacuum. On the OEM set up the VCV only goes to a carb vacuum port and NOT to the dizzy vacuum advance. I wonder if there needs to be a one way valve here or can you find another port on the carb to hook the VCV to. In other words I think this diagram is engineered to steal carb vacuum from the dizzy line b/c lack of carb vacuum ports???

Here is an image from the EVAP VCV in the original OEM system notice it doesn't affect vacuum advance on the dizzy:

Disclaimer: I am not a Fuji carb engineer!

 

[dannyvp]

The main vacuum advance port on the dizzy needs to go to a carb advancer port. Disclaimer, I am not a Fuji carb technician.

That’s what I have.

 

[dannyvp]

Big Update!!

I was double checking hose and saw an oil leak. So I crawl under the truck to see the oil leak. I see my carb cleaner sitting there and spray it on the leak, while I have it in hand I sprayed up on the exhaust, on one corner the engine rev’d up.
So I checked the 3 exhaust bolts and one is threaded backwards and loose. After burning my arm, Accidentally I grounded out the carb fan and it came on i got that bolt tightened up and the carb has seemed to tune out.
I drove it around the block and it died at the stop sign. So I got it home and after it is rev’d up for a bit, when you let of the gas it will die.

So I’m closer. I think I might have the main part of the problem figured out.

 

[cheeese]

Be careful with carb cleaner and hot exhaust, also heat and brake cleaner is a bad combination. But good to hear progress!

 

[dannyvp]

I think this joint is heating up and loosing up causing me some issues.
Is it suppose to have a gasket?

 

[NeverGiveUpYota]

I think this joint is heating up and loosing up causing me some issues.
Is it suppose to have a gasket?View attachment 2046281

Yeah it has a donut that’s sits down into the lower section.

 

[dannyvp]

Ok so I have the vac leaks found. I have the carb tuned. The engine idles like a champ! Drives awesome for the first 5 minutes, then it starts surging and causes bad running problems. It will be bucking and jumping.
Is there a valve or something that opens at certain temps that can cause this?

 

[NeverGiveUpYota]

Pull open your driver kick panel and try unplugging and then plugging back the emissions computer. Sometimes that can reboot it. Not guaranteed but it’s a shot in the dark. Some will actually ground the carb solenoid to the body of the carb too. I can’t remember the wiring on a CR but it can force the computer to reboot.

 

[dannyvp]

Pull open your driver kick panel and try unplugging and then plugging back the emissions computer. Sometimes that can reboot it. Not guaranteed but it’s a shot in the dark. Some will actually ground the carb solenoid to the body of the carb too. I can’t remember the wiring on a CR but it can force the computer to reboot.

Unpluged the Emissions Computer, left it unplugged for a minute, plugged back up and went for a drive. No change.
I also checked the HAI and the valve is open to allow cold air into the intake. (even though being desmogged, its the same air.)

 

[NeverGiveUpYota]

You do get a click from the solenoid right? Turn key so its on but not started. Unplug the solenoid, does it click when you plug it back in. If the truck is idling and you unplug it, does it stall out?

 

[dannyvp]

You do get a click from the solenoid right? Turn key so its on but not started. Unplug the solenoid, does it click when you plug it back in. If the truck is idling and you unplug it, does it stall out?

I get the click when not running, I have never unplugged when running.

 

[NeverGiveUpYota]

I get the click when not running, I have never unplugged when running.

While idling, it should make it stall out.

 

[NeverGiveUpYota]

Ok so I have the vac leaks found. I have the carb tuned. The engine idles like a champ! Drives awesome for the first 5 minutes, then it starts surging and causes bad running problems. It will be bucking and jumping.
Is there a valve or something that opens at certain temps that can cause this?

And yes the bvsv opens due to temp ie: it’s the two that are on the tsat housing. Are you running the top violet one?

 

[dannyvp]

And yes the bvsv opens due to temp ie: it’s the two that are on the tsat housing. Are you running the top violet one?

No I do not have either.

 

[NeverGiveUpYota]

No I do not have either.

Sorry, I couldn’t remember.

 

[dannyvp]

Started it up after a night of cooling and I could not even pull out of the drive way. I had to feather and give lots of gas just to get it parked again. So its not just a after warming up problem, what ever happened changed its running status.

 

[dannyvp]

New distributer cap, rotor, seal.
New OEM plugs and wires also.

 

[dannyvp]

So I checked the timing after warm up. It was set to "0" according to my gun. I know for a fact I set it to "10" yesterday. So I reset it to "10"n just now. On the test drive it still lurched and jumped and hesitated, but not as bad. Does this mean I need to advance my timing some more?
What could cause you to loose timing?