Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ Throttle body question

Posted by: Strudelwagon Jun 22 2009, 09:13 AM

Hi,
I have a 74 2.0 FI that some of the emission bits have been removed. While gathering the missing bits I noticed that the schematics for the vacuum hoses show that the vacuum ports on the distributer hook up to the ports on the T-body.
Only one problem..I only have 1 vacuum port on the T-body and 2 on the distributor.
anyone know why this is?

Thanks
SW

Posted by: Dr. Roger Jun 22 2009, 09:32 AM

there's two types of vacuum. above the carb's throttle plate, and below the plate.

one supplies vacuum when at idle and at lower engine load (below), and the other supplies vacuum when the throttle is opened up (above).

one port is located either just below the carb or along the intake runner, and the other is just above it at the carb.

Posted by: kwales Jun 22 2009, 09:54 AM

One of the dual hose distributors has a hose to nowhere that just hangs down and hooks to nothing...

Anyone want to chime in on which version has this unusual WTF feature....

Posted by: SLITS Jun 22 2009, 11:33 AM

Sure .... The '73 2.0L TB had ports for vacuum advance / retard. Between '73 & '74, the engineers decided that vacuum advance was not necessary so the eliminated one vac port on the TB. While both sides of the vac can on the dizzy had hoses connected to it, only one (vac retard) was actually hooked to the TB. Both units carry the same part number ..... 039 133 067

Dates are approximate as I doubt the factory doesn't have documentation on when the change occured.

Images if desired, but they're gonna cost ya!!!

Posted by: Derek Seymour Jun 22 2009, 11:58 AM

If your EGR system was removed then you "should" have a open port on the throttle body that points in the direction of the passenger side firewall. Normally this was used as the vacuum advance for the EGR valve. You can attach the distibutor advance (smaller black hose) to this port. If for some reason that port is missing from the throttle body and you only have the retard port that points straight back at the rear firewall then you can just leave the advance alone.

Posted by: Strudelwagon Jun 22 2009, 03:03 PM

Thanks Guys,
I kinda figured it was a odd setup to have a hose to nowhere but maybe not so wierd for a 914.
SW

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)