Air injection pump. Remove all the pipes and plug the hole on the rear of the heads. The plug and sealing rings are available at 928I. At least they were when I did it 6 years ago.

The decel valve isn't a bad thing. I disconnected it because with my alternate engine tuning it wasn't working right.

 

If you yank the decel valve, may as well put on a euro throttle body. (they dont have one).

 

i wish i could find one......

 

I did put a euro throttle body on, the micro switches were fun. I'll snap a pic tonight.

 

I have a Euro throttle body, and a deac valve. K-jet, though.

 

why fun? you should port match the Ljet "U" to match the larger throttle body, but its certainly not a requirement.

the euro 84-5 throttle bodies are really nice, because you just cut the wires over to the self contained microswitch for off throttle and WOT.

now, the older throttle bodies are still fine, but you have to make a little bracket out of a small piece of steel , drill a hole, bend a 90degree into it, and attach the stock microswitch set up.

 

My 83 K-jet has the valve...but so far I have no issues with it, or even anything, touch wood.
jp 83 Euro S AT 52k.

 

where do i get an affordable vacuum limiter if i want one? 1980 928 US 4.5L L-jetronic

 

May still be available new $524 Porsche list, one site shows $337 or used from 928 International 1/2 off at $47.50 part # 930-110-173-00 which indicates it was first used on the 911 Turbo.

 

You're apparently really new. What you need is the "PET" program that shows all the parts in the car in blow-up diagrams along with part numbers. Then stick the part numbers into google to search the internet. We all have our favorite sites and you'll develop yours.

One key site for 928 ownership is 928 International as they sell a complete selection of parts and have many, many used parts in stock. As Jim notes, a used one is on sale now for dimes-on-the-dollar compared to new.

Reminds me that I need to place an order there. If only I could tell what break-downs I'll have in the next year. My 928 ownership adventure has always been surprising; why should it stop now?