Topic: 22R Distributor Vacuum Advance Qs

[CivicFerio]

Hello Everyone!

I'm getting my 84 4X4 XtraCab with 22R ready for smog. So far the engine has been running good with 230K miles on the original motor (according to the previous owner).

Here is the question. Underhood Label says Ignition Timing must be at 5° BTDC with (2) both vacuum lines off the distributor. But when I plug back in the vacuum lines it remains at 5°. I check the vacuum and one is at 5in. Hg and no vacuum on the other hose during idle. The other hose however gets very good vacuum at around 20in. Hg when the throttle is slightly open (is this ported vacuum??).

Vacuum from the other vac. hoses at idle is 18in. Hg while the one going to the distributor only gets 5in. Hg. Is this normal or do I have a vacuum leak? Also both ports of the Distributor Vacuum Advancer diaphragm doesn't hold vacuum, is it busted or normal? Thank you!!

[Duffil]

Yeah, it's ported vacuum.  You don't get any advance till you rev 'er up.

[79coyotefrg]

and if the dist  cant hold a manual vacuum  its got a bad diaphram

but the lines do get vacuum at different stages of throttle

[shermota]

Just a note on smog, I could not get my truck to pass. I had new everything, carb, distributor, head, ect.... It had all ben replaced. I just was barely over. I ended up taking off my rock crawling tires and putting stock tires on. Made a big enough difference for me to pass. So just FYI

[Wermz84]

That's funny, I was reading this and could not figure out what Hg was.  Then I realized what you were talking about, mine vacuum tester uses a different measurement.

Anyway.  I just did this last nite on my 84 truck. Same thing, 5⁰BTDC either way.  With or without the vacuum advance, or the HVAC, lines.  Or combination of the two..

And if you just bought the vehicle or are thinking about it and your unsure about the smog history check this out..  CA only.
http://www.smogcheck.ca.gov/vehtests/pubtstqry.aspx

[acerbis]

Wermz84, WAS YOUR DISTRIBUTOR BAD? Mine is doing the same.

[myyota]

I have an 84 4Runner, and had to replace the vacuum advance because both diaphragms were bad. I went to all the wrecking yards looking for one and all the local parts stores around me, nobody had it so iended up ordering it from the dealer. it cost me 200 dollars for the vacuum advance (no, im not kidding).