Puzzling start issue...
 

Hey everyone,

I've been reading these forums for a while and have gotten some great fix-it-myself tips for my '74 911s. But I have a situation now that hasn't been posed before...

As mentioned, the car is a 74 911s, has a history of running great. Put a new(er) Bosch CD unit in last spring. Car was stored all winter in an enclosed trailer.

The car needed to be jump started (my trickle charger got unplugged!). Fired up, ran great. Idled great. Shut it off and went to have dinner.

30 minutes later I go to start the car, and it cranks but no fire. I tried with the jump starter, cranks but no fire. I smell gas in the engine bay, so I'm sure fuel is getting there.

The CD unit makes its characterisitc high-pitched whine. The coil (3 yers old) meters out at just over 600ohms and .5 ohms across the primary and secondary terminals.

Pulled a boot and stck a plug in to check for spark... NOTHING!

So in 30 minutes of sitting, my car went from running great, to no spark. What gives?

ANy suggestions would be great. I'll be under the hood this weekend trying to get to the bottom of this.

Is the CIS in a 74 like the CIS in a 73.5? If so, there are points in the distributor that trigger the CD box

Jim,
I've never seen/looked at a 73.5 CIS. My guess is yes? What should I look at to determine this?

-Rob

Inside the distributor, is a set of points, they should be gapped (not sure of specification). Anyway, turn the motor over by hand and see if the points open and close (assuming there is points).

Points should be set w/ a dwell meter @ 38 degrees +/- 3. I like to set them @ 35 or 36 to start, then the angle will gradually grow to 41, when it's time for a change.

Also see RarlyL8's current thread on hard starting w/ CIS. He had a bad ignition switch.