Vacuum Test Port Tap Location on Intake Manifold?

[Ackcruisers]

It looks like all FJ40 vacuum unions to intake manifold are NLA from Toyota. All my intake ports are plugged. My truck is de-smogged and no brake booster. For testing/tuning purposes, can you temporarily remove the ventilation (blue circle) hose and connect gauge there? My truck also has vacuum advance dizzy and Chinese carb with vacuum hose fitting but that will not give me an idle vacuum reading.

Also, when I eventually add brake booster, what union port do I tap into (Red or green circle below)?

 

[4Cruisers]

There's always this:

Union (For Front Drive Shift) - Part Number 90404-51093

This is on the 3FE intake plenum for the transfer case front drive shift. There should be plenty of these floating around, from those like me who have converted theirs to manual front drive engagement. Or, they're still available new - retail $22.38 .

 

[Ackcruisers]

There's always this:

Union (For Front Drive Shift) - Part Number 90404-51093

This is on the 3FE intake plenum for the transfer case front drive shift. There should be plenty of these floating around, from those like me who have converted theirs to manual front drive engagement. Or, they're still available new - retail $22.38 .

View attachment 2396227

Thanks, much appreciated. It’s available for $16.15 here. I just got lucky and ordered the last OEM Toyota Union Vacuum Hose (For Manifold Side, For Tandem Brake Booster) #90404-51007 In USA $9.39. EPC shows that part number is for front disc brake 9/79 - 8/80 link here. Not sure if it matters but they do show different union part number for front drum models.

I guess I’ll need to wait until it arrives to get proper vacuum reading with my new test gauge...

 

[tls3601]

Realize vac readings at high elevations will be lower. My ‘78 that runs damn near perfect pulls a steady 16.5 at 5400 ft. Nice solution you came up with there

 

[4Cruisers]

Realize vac readings at high elevations will be lower. My ‘78 that runs damn near perfect pulls a steady 16.5 at 5400 ft. Nice solution you came up with there

My '76 FJ40 with ~66,000 miles runs well at 7,240 feet with 15.3 in Hg.

 

[brian]

just pull the pcv hose off the intake.

 

[Ackcruisers]

just pull the pcv hose off the intake.

Perfect timing. Just finished torquing head bolts and adjusting valves. My next step was to set timing and adjust carb using lean drop method.

 

[Ackcruisers]

Realize vac readings at high elevations will be lower. My ‘78 that runs damn near perfect pulls a steady 16.5 at 5400 ft. Nice solution you came up with there

My '76 FJ40 with ~66,000 miles runs well at 7,240 feet with 15.3 in Hg.

Thanks to @brian I attached my new vacuum tester gauge to the exhaust manifold union PCV hose port. Was able to get a reading of 20.5 - 21 at idle. I’m 20feet above sea level.

Below is video.


Timing
My timing is set to 7 degrees BTDC.

Valves
Adjusted the following valves :

Group A
cylinder 1 TDC
1 - .014 was a bit too tight, loosened
2 - .008 OK
3 - .008 Ok
5 - .014 a bit too tight, loosened
7 - .008 - Ok
9 - .014 - loosen a bit, too tight

Group B
cylinder # 6 TDC
12 - .014 - a bit too tight, loosened
11 - .008 - ok
10 - .008 - ok
8 - .014 - a bit too tight, loosened
6 - .008 - ok
4 - .014 - ok

I will be redoing the lean drop method using vacuum gauge in the morning to see if it can make the needle a bit more steady at idle.

 

[65swb45]

FWIW, I have a BIG box of vacuum fittings available.

 

[Kschep]

Can you show a pic of where your attaching that vac line? The PCV fitting pls - thx!

 

[Ackcruisers]

Can you show a pic of where your attaching that vac line? The PCV fitting pls - thx!

The very first image in this thread shows the PCV vent hose attached to intake manifold. It’s circled in blue. That’s where I connected my vacuum gauge to test motor and perform the lean drop carb adjustment.

 

[OhioFJ]

My brake booster is attached at the red circle.

 

[Ackcruisers]

Wanted to post the vacuum results after the lean drop carb adjustment, valve adjustment and setting timing to 10 degrees BTDC.

I found my choke cable linkage was binding a bit and it was impacting the fast idle. This was interfering with the lean drop adjustment. After correcting, I followed the process outlined here.

Based on the vacuum reading, E.g. the needle was moving 20-20.5 -21, which according to the Vacuum 101 tech post here, It pointed me to the spark plug gap. Removed my plugs and set gap to .038 they were factory OEM plugs with gap set at .028. This adjustment made vacuum reading a bit more steady but it is still vibrating. Since I’m running electronic points I may have to set gap a little more..

Here is the latest video with readings. The truck has great power and is idling well at around 650. Not sure what else I can do to get needle pinned and no movement.

 

[bhsdriller]

That actually looks really good, I wouldn't stress about it too much if it's running well.

 

[Ackcruisers]

That actually looks really good, I wouldn't stress about it too much if it's running well.

Thanks, sometimes working on this I turn into Phaedrus in search of quality (or perfection) in the book “Zen and the Art of Motorcycle (FJ40) Maintenance”

 

[david2]

Hello

This circled fitting is no longer available, Toyota #90407-53001, would anyone recommend and alternative? it this 3/8" BSPT? advise will be greatly appreciated

 

[brian]

$or

 

[65swb45]

Place a want ad in the classifieds. There are a few of us that have them.

 

[DieselFJ]

@65swb45 I know this is an old thread, but wondering if you happen to still have part number 90407-53001 available used. I'm in need of one. I'm also looking for a carb insulator for a '78.

 

[Malleus]

Thanks, much appreciated. It’s available for $16.15 here. I just got lucky and ordered the last OEM Toyota Union Vacuum Hose (For Manifold Side, For Tandem Brake Booster) #90404-51007 In USA $9.39. EPC shows that part number is for front disc brake 9/79 - 8/80 link here. Not sure if it matters but they do show different union part number for front drum models.
View attachment 2396319
I guess I’ll need to wait until it arrives to get proper vacuum reading with my new test gauge...

That's interesting. My '77 is 252398; Amayama says 90404-53003 is for FJ40 -0000001 to FJ40 -0327525,

FJ4#,55..LHD FOR FRONT DRUM BRAKE

but my front brakes are discs. I'm not liking this EPC list very much.