Vacuum test steps (with video)

[mochosla]

Hi Everyone. So, as I continue to get my truck ready for a smog test, I decided to do a vacuum test as instructed by the manual. All feedback is welcome.

The steps in the manual are as follows:

The desired readings are assumed at sea level. If you are at high altitude, the reading will drop about an inch of mercury for every 1000' of elevation.
Allow the car to warm up to normal operating temperature
Connect the vacuum gauge directly to the intake manifold port
The vacuum reading should be between 17-22 in-Hg with a steady needle.

See video and additional information from the manual below.

 

[OSS]

Vacuum is excellent. No vacuum leaks. When checking vacuum, it's what the engine is doing at idle that's important. Goosing the accelerator won't show you anything worthwhile, though it's fun to watch the needle drop. Just warm up the engine maybe 8 minutes and let it sit at normal low idle & watch what the needle is doing.

Yours looks great.

 

[mwebfj60]

That idle sounds fast, what RPMs?

 

[mochosla]

That idle sounds fast, what RPMs?

Yes, the RPM is high (900s) and that is the next adjustment I'm doing.

 

[Spike Strip]

Set the idle to spec, test vacuum at idle - But looks good from the vid.

Get the proper Air Cleaner wing nut with built-in gasket and keep crap out of the carb. Part # 90175-06003

Do you have the gasket that goes between Carb Air Horn and Air Cleaner ?

 

[mochosla]

Set the idle to spec, test vacuum at idle - But looks good from the vid.

Get the proper Air Cleaner wing nut with built-in gasket and keep crap out of the carb. Part # 90175-06003

Do you have the gasket that goes between Carb Air Horn and Air Cleaner ?

View attachment 1529470

I do not. Where do I get these from? Toyota?

Thanks.

 

[Spike Strip]

17848-61020

Be aware, it has a groove that allows it to be fitted onto the bottom of the Air Cleaner - it doesn't just rest on the carb.

Any vendor should have it as well as Toyota

 

[batthewmrown]

Sorry for the totally novice question, but where is the intake manifold port that you're connecting the gauge to? Got a photo? Thanks!

 

[Spike Strip]

A/C idle up port works well. Just remove the hose that's on it. Replace after vac test.

 

[batthewmrown]

A/C idle up port works well. Just remove the hose that's on it. Replace after vac test.

MY HERO