View Full Version : Elan +2 headlight troubleshooting

12-09-2004, 10:24 AM
Now that I've got my Elan running, I was hoping that the vacuum system woulda sucked the headlights down, but it doesn't work yet.

According to the book for failsafe models, the two vacuum lines from the headlamp switches go to engine manifold and the single headlight pod. From what I gather, there's not a "vacuum resevoir" on federal versions.

My vacuum line is coming from a vacuum port on the intake for the front carb. It goes from there to the headlamp switch, then from the switch back to the vacuum cylinder that's connected to the headlight pods.

I've removed the line from the manifold when the engine is running and there is vacuum, but it seems weak. If I hook up a vacuum guage to this line, does anyone have any idea how much vacuum should be going through? What other tests can I do to isolate the problem?

I know I ask a lot of questions, and I do appreciate the expertise that everyone brings. Hope you don't give up on me too soon!

12-09-2004, 11:35 AM
Hello Hegg,
I would guess between 15 to 20 inches of mercury. I see from your other post that your car is not running too well. That could affect the vacuum figure you get.


12-09-2004, 11:38 AM
Makes sense. I haven't checked vacuum readings yet, but it feels quite strong through the carbs. I'll check readings on the headlight line and the distributor advance line to compare.


12-09-2004, 01:59 PM
Not to sure on the fail-safe system as my cars are non-failsafe but as far as I know BOTH systems use the front chassis box section as the vacuum resevoir, this "resevoir" often gets leaks due to rust around the front uprights.
There is also a one way valve in the manifold take off fitting, the rest of the pipes/connections also tend to leak or split and the headlight vacuum pod also rust and leak.
Regards Brian

Birkin T.Cam Seven