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Bentley never made a manual specific to the type 4. In the late type 4 haynes manual (green manual covering the 412 with 1.8 in the supplement) there is a complete vacuum routing. It is near teh front of the manual.

A large portion of the European models did not have retard...only vacuum. Also, it hooked in several places depending on the model of TB.

The diagram shown is of the early type 3 with the nonj-diaphram MPS. It used teh presure switch for full load enrichment. I believe none of thsoe had vacuum retard.

On the type 4 1.7.....vacuum advance taps into the 3mm vacuum port on the back side of teh idle screw on teh TB. The retard.....comes from the front side of the TB on a 4.5mm nipple that runs under the #1 and #2 runners.

It can also be "teed" into the line for teh vacuum deceleration valve that T's into the boot for the AAR on type 4. Ray

Hey, the vacuum retard from the throttle bottom runs underneath the air mix box and is probably sitting down by the edge of the dist. in the tin recease with a cracked hose end probably a greenish nose? It made a big change adding it after setting the timing! It is a tight space with the cooling flap rod and dist. to get at that hose! You have a great start of a car with the motor with low mileage and great exterior you should have her reving up after a good going over hoses and settings! It'll suprise you! I am actually very close now to the next test longer run with my car and I have a few main vent cables to get back right and then maybe to body work and paint! You will be getting there fast and hopefully wont have to add the re rebuild like I did!! If you have the thermostat still and in good shape it will help with start up! I start now in one to two turns which seems good! I think chking vacuum leaks is key! I think there is a small one at one of my intake rubber tubes! I used a shrynge from a inkjet kit to run alcohol along the edges and the idle changed on one.. ALso I had cracked hose ends at the engine vent hoses that go through the rear tin and above the cv axle area; they have a coupler peice. bill

Wow, what a week. I'm completely exhausted. I haven't had the chance to check into this thread for a few days now, and I wanted to say 'thanks' to those of you that have replied.

Vonkr: Your last picture was actually the electrical diagram, but thanks for posting it too (I'm guessing that was you that e-mailed it to me). I'm sure it will come in handy. When I said 'Vac-retard,' I was referring to the Vacuum retard feature on the distributor. As Ray mentioned, perhaps the European models did not have this feature, but the vacuum canister on the distributor has a port on the outside for the vacuum advance, and another port on the backside close to the distributor body for retarding the advance (pulls the vacuum controlled advance the other way....or off) for emissions. This car was bought new in the state of California, and cars sold here were subjected to stricter emmisions rules.

And thanks to you, Ray, for your posting. I was hoping I'd see a line or two from you. I've read your postings in Jen's thread (many times over !), and thank GOD that you are here to share your knowledge with us. It's been a long time since I've had an F.I. type-4, and I didn't have the experience/knowledge then to understand most of what was going on 'under there.' But, now I know where to look!

Keep us posted on your progress, Bill.

I've gotta run for now, but wanted to post a 'thanks' for now.


Travis