1985 stock emissions control (1 Viewer)

[Engineer8000]

When I first installed the 3fe I used a cone filter, no place to connect the distributor vent I didn't even know about. It took about a year before the distributor was toast. I modified the adapter to provide a connection for that. I've since installed the fj62 air box.

 

[CruiserTrash]

Why doesn’t Toyota use a simple check valve between the cabin fresh air supply and the dizzy? There’s be no need for the VCV in that case. Dizzy can always vent to air cleaner, no fumes in the cabin. The natural weak vac/suction of the air cleaner would draw air from the cabin and through the dizzy, thereby opening the check valve in the presence of flow.

 

[cps432]

Why doesn’t Toyota use a simple check valve between the cabin fresh air supply and the dizzy? There’s be no need for the VCV in that case. Dizzy can always vent to air cleaner, no fumes in the cabin. The natural weak vac/suction of the air cleaner would draw air from the cabin and through the dizzy, thereby opening the check valve in the presence of flow.

The vsv probably opens under heavier load to pull the fumes out of the system when there’s more demand for power. The valve in the charcoal canister evap system works this way. It opens under load and evacuates the fumes from the can when the engine is being taxed hard so the fumes can be cycled into the intake and burned properly. I updated my charcoal canister with the ACDelco swap. The OEM evap switch was non functioning so I found a vacuum actuated unit to fit in the purge line going back to the intake manifold. The vacuum comes off the dizzy advance and it opens the valve when the dizzy advance is actuated. Fumes only evacuate under load.

 

[CruiserTrash]

The vsv probably opens under heavier load to pull the fumes out of the system when there’s more demand for power. The valve in the charcoal canister evap system works this way. It opens under load and evacuates the fumes from the can when the engine is being taxed hard so the fumes can be cycled into the intake and burned properly. I updated my charcoal canister with the ACDelco swap. The OEM evap switch was non functioning so I found a vacuum actuated unit to fit in the purge line going back to the intake manifold. The vacuum comes off the dizzy advance and it opens the valve when the dizzy advance is actuated. Fumes only evacuate under load.

i need to address my likely-inop evap VCV too. Kind of wigged out about the fact that I have to go from three lines to two though.

 

[cps432]

i need to address my likely-inop evap VCV too. Kind of wigged out about the fact that I have to go from three lines to two though.

It’s so simple man. I’ll shoot a pic for you tomorrow. One of the best upgrades I’ve made.

 

[cps432]

i need to address my likely-inop evap VCV too. Kind of wigged out about the fact that I have to go from three lines to two though.

Edit: I should preface by saying my truck is desmogged, but this should work the same way. You may have to block off the evap line to the carb base… it’s been a while since I looked at the stock setup so I don’t remember what the carb looks like. (I’m running a Holley sniper)

Here are some pics of my setup. My electronic switch was inoperable so I sourced a vacuum operated switch to replace it. It’s from an old school Camaro. I’ll have to look up the part number… I just plumbed it between the evap can and the pcv. The vac line is T’d off the vac advance line so that the valve only opens under WOT. That way extra fumes aren’t throwing off your AFR under normal conditions. It only purges when you’re asking for more power. The other line just goes back to the tank vent. The acdelco can will fit the OEM bracket if you get longer bolts for the clamp. I think they’re 4” or so.

 

[CruiserTrash]

Edit: I should preface by saying my truck is desmogged, but this should work the same way. You may have to block off the evap line to the carb base… it’s been a while since I looked at the stock setup so I don’t remember what the carb looks like. (I’m running a Holley sniper)

Here are some pics of my setup. My electronic switch was inoperable so I sourced a vacuum operated switch to replace it. It’s from an old school Camaro. I’ll have to look up the part number… I just plumbed it between the evap can and the pcv. The vac line is T’d off the vac advance line so that the valve only opens under WOT. That way extra fumes aren’t throwing off your AFR under normal conditions. It only purges when you’re asking for more power. The other line just goes back to the tank vent. The acdelco can will fit the OEM bracket if you get longer bolts for the clamp. I think they’re 4” or so.View attachment 2985121View attachment 2985122View attachment 2985123View attachment 2985124View attachment 2985125

That all makes sense. I forget what the 3rd line is for on the stock one - I'll have to spend some time with the Emissions FSM again and compare your notes. I appreciate the photos and such - I really like how your system works.

 

[OSS]

The vac line is T’d off the vac advance line so that the valve only opens under WOT

Remember that the purging of the charcoal canister into the intake manifold is an emissions requirement- nothing else.

Since you don’t have to smog test this thing, I’d just vent the gas tank into the AC Delco canister IN pipe and let the canister OUT pipe just breathe to atmosphere somewhere. Don’t suck it into the engine.

I’ve got a feeling that the way you’ve got it hooked up now, when that vacuum switch opens - it messes with the air fuel ratio - Possibly making it too lean = really bad.
I don’t know if it does or not - but it looks suspicious.
Also it may interfere with the functioning of the PCV - siphoning off vacuum.

 

[cps432]

Remember that the purging of the charcoal canister into the intake manifold is an emissions requirement- nothing else.

Since you don’t have to smog test this thing, I’d just vent the gas tank into the AC Delco canister IN pipe and let the canister OUT pipe just breathe to atmosphere somewhere. Don’t suck it into the engine.

I’ve got a feeling that the way you’ve got it hooked up now, when that vacuum switch opens - it messes with the air fuel ratio - Possibly making it too lean = really bad.
I don’t know if it does or not - but it looks suspicious.
Also it may interfere with the functioning of the PCV - siphoning off vacuum.

Sniper shows that I cruise around 13:1 - 14:1 while on the throttle. When I let off the gas it will blip up to 20:1 for a moment until I tap the gas again or down shift. I don’t think it’s causing any problems, but you might be right. It might cause the ratio to spike on deceleration… I’m currently on the road headed west and this truck is running better than ever. I have no power loss issues aside from the standard 2F sluggishness on long inclines, but it’s nowhere near what it was when running the carburetor. I’m getting around 240-250 miles on a tank. That’s about what the carb was doing. I’ll take it!