82 vacuum - tbi's
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,692
Likes: 29
From: Texas
82 vacuum - tbi's
Suddenly, I cannot read the vacuum on my TBI's.
Before we get started, understand, I have been doing this for at least a decade or more and know the procedure by heart.
Have even bought a new vacuum guage to make sure that was not the problem. Now have 3 guages! None register any vacuum.
Engine idles nicely as I manually adjust it to be a smooth idle with no throttle. About standard - 650 rpm.
Yet nothing I do will produce a vacuum reading on the guages - except for manually holding the throttle open more. Then it will jump up to a higher level of vacuum - 12" maybe more depending how fine I can hold open the throttle.
Car runs OK, but something is wrong. I can make any adjustment I want on the driver TBI and no vacuum reading. Same with passenger side. So I just adjust by "ear" and "driveability", adjusting the TPS as needed.
What gives?
Before we go off on a rabbit hole, I have no vacuum leaks anywhere.
Before we get started, understand, I have been doing this for at least a decade or more and know the procedure by heart.
Have even bought a new vacuum guage to make sure that was not the problem. Now have 3 guages! None register any vacuum.
Engine idles nicely as I manually adjust it to be a smooth idle with no throttle. About standard - 650 rpm.
Yet nothing I do will produce a vacuum reading on the guages - except for manually holding the throttle open more. Then it will jump up to a higher level of vacuum - 12" maybe more depending how fine I can hold open the throttle.
Car runs OK, but something is wrong. I can make any adjustment I want on the driver TBI and no vacuum reading. Same with passenger side. So I just adjust by "ear" and "driveability", adjusting the TPS as needed.
What gives?
Before we go off on a rabbit hole, I have no vacuum leaks anywhere.
Burning Brakes
Joined: Mar 2010
Posts: 943
Likes: 15
From: Valdosta Georgia
I had that issue once, it turned out that I had the screws backed out too far. It doesn't seem that would be your issue here, though. Have you used a small wire to see if the ports are blocked by varnish or something else? Guitar string works well for that. I'll be watching this thread to see what you find out.
I was still getting plenty of vacuum through the other ports, just not the balance ports.
I was still getting plenty of vacuum through the other ports, just not the balance ports.
Last edited by Drawmain; May 13, 2015 at 10:22 PM.
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,692
Likes: 29
From: Texas
Looks like it was a clogged vacuum port - after 33 years and 240K miles! No wonder. Great vacuum through other ports. Can feed the spray tube from gumout into port and spray would not go through. Used a very long needle wife had and got it opened enough so that spraying again cleared it. Now to go through the proper procedures and set everything properly. Sometimes the obvious escape you. Thanks again.
