1969 911 T Project - Ignition Setup

[scottjk]

Just took delivery of a solid body 1969 911 T project car. Engine ran but PO was chasing some misfire issues and started to install a 123 dizzy but lost interest before he got it running again. This is my first pre-CIS 911 so I'm learning as I go... be easy on me. I've searched and read but it's difficult to conclude what a current good combination setup would be.

Odometer reads 76k and from the overall condition of the car I believe it to be close. Current ignition system consists of what looks like the original black coil, old Permatune box and 2 wire 123 Distributor.

I've been reading on the MSD and CDI+ units. Ultimately this car will be stripped and dipped for a ST build and modified 2.5 engine install. For right now I'm just trying to get it running again. PO said he thinks the Permatune or coil are bad.

So many options... so much confusion. MSD, Partsklassic, CDI+, Permatune.

What would you recommend?

[edmayo]

What do you describe is a misfire issue? When does it occur? Are all the spark plugs the same color? What brand and number are the spark plugs? Have you measured the resistance of each spark plug wire, with its spark plug connector? What is that red wire with the butt connector do? Ignition? Those look like 40 IDT carbs, what is idle jet size? Are the idle and main jets clean? Have the float levels been checked? Diagnosis is a step by step process of elimination, hopefully this will give some stuff to check, that's how its done.

[scottjk]

Thanks for the reply. Sorry that my post wasn't more clear. I'm going to go ahead and replace the CDI and Coil and I was hoping to get recommendations of the current best set up to use with the 123 dizzy that I already have. I'm looking at the Partsklassic CDI and coil as well as the MSD setup. Eventually I'd like to build a 2.5 twin plug. I'm just trying to buy items that will work in that application so I don't have to buy twice. I haven't decided if OE look is import to me yet or not.

[1969911T]

For my 69T, NGK BP6ES plugs, original Marelli distributor with standard coil, and wires works well. Add MSD CDI, Clewett wires, MSD Coil and Tach adaptor and you get easier starting and certainly seems to be better power. I do not know anything about the 123 dizzy.
Steve

[scottjk]

For my 69T, NGK BP6ES plugs, original Marelli distributor with standard coil, and wires works well. Add MSD CDI, Clewett wires, MSD Coil and Tach adaptor and you get easier starting and certainly seems to be better power. I do not know anything about the 123 dizzy.
Steve

Thanks. I've pulled the plugs and started a leak down check to see what I actually purchased. I've decided to install the original Bosch dizzy that came with the car. PO showed me a video of the car running a few month previous with the original so that will be a good starting point.

[rgupta250]

Back to basics/original parts…I like that approach!

[scottjk]

Found #4 at 80% leakage. Triple checked TDC multiple times including manual rotate through all cylinders while applying 30% PSI to make sure that indeed I was TDC on #4. All others less than 5%. Very strange. Sounded like most leakage coming from intake valve. Also noticed that every spark plug except #4 showed normal burn patterns. #4 plug looked brand new with no signs of detonation so definitely not producing enough compression to ignite. I pulled the top and bottom valve covers. Put #4 at TDC and backed the valve adjustment screw completely out and rotated the engine a couple of times. Took a new reading at TDC and got 4% leakage. Readjusted the valve gap, rotated the engine by hand a couple more times and again was able to get 4% leakage. Stuck valve? Mis gapped?

Have anyone of you experienced anything like this? The true test will be tomorrow when I put it all back together and try to start it. I've removed the 123 dizzy and replaced with the original Bosch unit.

[edmayo]

Sounds like you're on the right track. It very often comes back to checking basics first. Very possible valve was just stuck in the guide.

[scottjk]

Got it fired up. Final conclusion was that #4 stuck valve was due to not running for awhile and sitting because #4 plug wire was bad. Probably would have corrected itself as soon as I change the #4 wire.

[sbsurfer]

If you end up running the 123 later down the road I'm using the coil from 123 and MSD 6AL (PN 6425). I really like the 123, the flexibility in adjusting the timing curve to fine tune the engine, the dashboard on the app while driving is really nice (i have my phone on a magnet mount attached to my ash tray....and the disable feature for theft prevention. It's been a nice addition to the car.