Gas filter vacuum source

[FishTacos]

I took my emissions system down for a complete desmog (keeping HAC, decel fuel cut, CO, stock carb/distributor) and I discovered that the "gas filter" was preciously jb welded and then broken off and abandoned to breathe fresh air.

This first photo is the vacuum source as it was before disassembly.

The second is what I have done to the manifold so far.

The third is the source I plan to use for my desmog.

I had to tap out the forward port to 1/8 npt to get a brass fitting to thread in securely. The aft vacuum port is plugged with a square headed brass fitting but only finger tight because I was not sure I could source vacuum this way and I wanted to be sure i could thread this weird (fj40?) vac port back in somewhere if I had to.

My question is this: Why are there two ports cut into the mani and are they different? Is one better? Is this cobbled brass fitting a reliable way to get vacuum?

 

[Joe_E]

You need that top pic flash gordon looking vac port in the hole that is near the firewall. It is for brake booster vacuum. The little side nipple is for the a/c kick up i believe.

 

[FishTacos]

That makes sense.

Thanks Joe.

 

[GeologistFelix]

The place you have your brass T connector is where the Gas Filter (little plastic dealie with three ports on top) goes. Inside, there's a little puck of compressed wire that catches debris and keeps flame from going up the vac lines if you backfire into the manifold.

If you want to put in-line filters on the lines coming off of your two ports there, you'll probably be fine.

As for the connector with the cooling fins...main port is for the brake booster, as stated before, and the side one is for the AC idle-up circuit. I keep a cap on the AC port and use it for my vac gauge when I want to check the manifold vacuum.

 

[FishTacos]

I plan on putting some stainless steel scrubby in the middle of that T. I thought it was probably there on the broken-in-half, jb welded three times "gas filter" to keep debris out of the intake. The backfire thing never dawned on me. This 60 has been known to backfire occasionally too. Thanks Felix

 

[worldspan]

FishTacos - Do you know what size thread and pitch that gas filter is? Do you know if they are different sizes from different year 2F intakes?

 

[FishTacos]

FishTacos - Do you know what size thread and pitch that gas filter is? Do you know if they are different sizes from different year 2F intakes?

The two vac ports on the intake are 1/8 bspt. This is just a little smaller than 1/8 npt and very uncommon in the states. All 2F intake manifolds are the same assuming the one you have is unmolested. A "gas filter" can be obtained at a pick and pull junk yard from many 80s and 90s Japanese vehicles. Just try to find one with the proper number and sized nipples. I desmoged and cobbled one out of brass plumbing fixtures but this was kind of dumb because i eliminated the filter function and had to tap the port to 1/8 npt. Now there is no going back to a stock "gas filter" unless i spring for an intake manifold. HTH. By the way, what are you trying to solve?

 

[worldspan]

The two vac ports on the intake are 1/8 bspt. This is just a little smaller than 1/8 npt and very uncommon in the states. All 2F intake manifolds are the same assuming the one you have is unmolested. A "gas filter" can be obtained at a pick and pull junk yard from many 80s and 90s Japanese vehicles. Just try to find one with the proper number and sized nipples. I desmoged and cobbled one out of brass plumbing fixtures but this was kind of dumb because i eliminated the filter function and had to tap the port to 1/8 npt. Now there is no going back to a stock "gas filter" unless i spring for an intake manifold. HTH. By the way, what are you trying to solve?

Thanks for the info.

I'm trying to solve bad hesitation at rapid acceleration. I want to make sure I have no vacuum leakage anywhere first.

This issue is driving me nuts

 

[GeologistFelix]

I had (and still have, when the engine is dead cold) a hesitation when I really put the pedal down.

Here's what solved it:

1. Reset timing
2. Reset idle mix and speed
3. Adjusted carb float a bit higher

Any or all of those could be factors (or all three could already be perfect...), and they're relatively easy to check, and the first two are very easy to fix.

 

[worldspan]

I had (and still have, when the engine is dead cold) a hesitation when I really put the pedal down.

Here's what solved it:

1. Reset timing
2. Reset idle mix and speed
3. Adjusted carb float a bit higher

Any or all of those could be factors (or all three could already be perfect...), and they're relatively easy to check, and the first two are very easy to fix.

1) Timing is set to 7* BDTC. I've also set it to more to see what happens and nothing really changes
2) I've tweaked these to do a lean drop method but to no avail. With the idle mixture screw turned out 2.5 turns from its seated position, where should the idle speed screw initially be turned to?
3) I'll adjust the float again but fuel is in the middle of sight glass

I've been told to check/adjust my Accelerator Pump but I'm not sure where to bend to AP linkage to get the necessary 9.5mm distance from top to bottom. Also, i clearly see fuel being spewed out the nozzle while the AP is throttled. Can too much fuel cause hesitation.

Sorry for the hijack

 

[GeologistFelix]

1) Timing is set to 7* BDTC. I've also set it to more to see what happens and nothing really changes
2) I've tweaked these to do a lean drop method but to no avail. With the idle mixture screw turned out 2.5 turns from its seated position, where should the idle speed screw initially be turned to?
3) I'll adjust the float again but fuel is in the middle of sight glass

I've been told to check/adjust my Accelerator Pump but I'm not sure where to bend to AP linkage to get the necessary 9.5mm distance from top to bottom. Also, i clearly see fuel being spewed out the nozzle while the AP is throttled. Can too much fuel cause hesitation.

Sorry for the hijack

Sounds like timing is good...mine was hesitating (and hard-starting) because of too much advance.

For the idle, you want to get it roughly where you want it (2.5 turns), and then set the idle speed to 650ish. Then you open up (unscrew; counter-clockwise) the idle mix screw until it stops increasing the idle speed. Then, adjust the speed screw until it wants to run at 690, then you lean out the mix (tighten the mix screw/turn clockwise) until it drops down to 650. Should only take like half a turn from where the RPMs maxed out with the mix screw.

For the accelerator pump, I kind of doubt it's too much fuel causing the hesitation. I forgot to mention that I fiddled with mine to get a bigger spurt and that also helped. I didn't have any luck bending the linkage like it says to in the FSM; I just put a nut in as a spacer where the rocker arm is connected to the rod with the spring.

Is the hesitation problem still a problem when the engine is hot? Is it better/worse?

 

[worldspan]

I just put a nut in as a spacer where the rocker arm is connected to the rod with the spring.

Is the hesitation problem still a problem when the engine is hot? Is it better/worse?

Can you post a pic of where exactly you put the spacer?

I guess it runs better when hot. It runs fine with the choke pulled too, forgot to mention that. It's got to be a fuel delivery issue or vac leak but i'm desmogged so not much to check.

 

[GeologistFelix]

It doesn't hesitate with the choke out? And less when it's warm? Hm. I definitely suggest getting that idle speed/mix tuned in.

As for where I put my spacer, here's a picture with the area on the carb circled.

The nut went where the washer is, in the stock setup, which keeps the spring from pushing the arm up off of the rod. So, the arm moves down 1/4" of an inch or whatever, which raises the plunger up by about that much on the other side.