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914World.com _ 914World Garage _ throttle body differences

Posted by: mipstien Jun 29 2010, 10:49 AM

went out today to replace my tps so i pulled the old throttle body off and began comparing the 2 different pieces i have and mine has a huge spring on it and the one i got does not have the spring and no extra arm to attached a spring to it. why is that? what are the differences and what are the advantages and disadvantages.
i do know that my current accelerator peddle is quite sticky and hard to push.

IPB Image

Posted by: underthetire Jun 29 2010, 11:06 AM

The pedal is a totally different problem, either the hinge rusted out in the pedal or the cable is bad.

Posted by: Markl Jun 29 2010, 11:15 AM

The top one matches the one I'm using and my spares - the spring closes the throttle in case your pedal or cable breaks (I think - haven't actually tried it). Check pedal hinge - rusty?

Posted by: vsg914 Jun 29 2010, 12:05 PM

The top one is from a 75/76. The bottom one is from a 73 (it has both vacuum ports.) Use the 73. You can hook up the vacuum advance on the diz (if yours has one), and its much easier to push without that extra spring. I think they added the spring to make sure the throttle closed quickly. An emissions thing I think.

Posted by: mipstien Jun 29 2010, 12:16 PM

the bottom one doesn't have the vacuum advance. the cables feels bad because when i unhook the cable the pedal moves around freely

Posted by: vsg914 Jun 29 2010, 01:27 PM

The bottom pic looks like it has two vacuum ports on it. Is that just something that looks like it attached? Looks like a brass nipple. If its not its from a 74

Posted by: mipstien Jun 29 2010, 01:43 PM

thats the same as the top its the pice that the TPS sits on

Posted by: vsg914 Jun 29 2010, 02:20 PM

Duh! I see it. Throttle shaft. 74, I think, was the only year for that one

Posted by: mipstien Jun 29 2010, 06:20 PM

http://www.autoatlanta.com/porsche-parts/porsche-914-parts/702-00.php

which of those is the correct throttle cable? it looks like the first part number but i just wanna be 100% sure.

Posted by: mipstien Jun 30 2010, 05:30 AM

anybody know?

Posted by: McMark Jun 30 2010, 11:18 AM

AFAIK, the 914 423 067 02 supercedes the 914 423 067 00 number. So either one should work, but 914 423 067 02 is the more available and newest design. But don't ask me what the design differences are...

Posted by: jk76.914 Jun 30 2010, 02:10 PM

914.423.067.00 1.7, 2.0 (discontinued)
914.423.067.02 1.7,1.8 (L-Jet), 2.0
914.423.067.03 1.8 (carbs, Europe)
914.423.066.00 914/6

This from my hard copy parts manual, Dr. Ing. h.c.F. Porsche AG. They indicate discontinued by showing the number with a line through it. My manual is probably 15 years old. Why George has the .00 version if it was discontineud I can't imagine but he needs to chime in here.... Note that his .00 version is only a third the price of his .02.

From my recollection, going way way back, I seem to recall that my 914 2.0 came with with a throttle cable that didn't have the plastic lining inside. When my throttle was sticking bad, I replaced it and the new one had the white plastic lining. (Turned out to be a rusty hinge on the pedal, not the cable.) Anyway that was 25 years ago, or more, and my memory may be fogged up, but that could possibly be the difference between the .00 and the .02.

Jim

PS- the second spring wasn't for emissions, it was for safety. New laws required redundant throttle springs. This was done in a clever way, in that only the coil spring going from the throttle shaft lever on the throttle body to the throttle cable anchor plate acts on the throttle plate normally. If it breaks, the big torsion spring on the throttle shaft will close the throttle. You can tell your primary spring broke because the secondary spring is much stiffer. Watch it in action and see what I mean. This way, they didn't double the spring force when that added that obligitory dual spring set up.