'70 D-jet runs terrible cold, great when warm,, Please share your wisdom Options

[Porsche Rescue]

Car starts when cold (not quickly, but it does start, air temp. 80 degrees), then it is a bitch to keep it going. Once on the road and warmed up it performs beautifully.

I have checked the Aux. Air Valve and it is sucking when cold, plugged when hot.
I replaced the head temp sensor even though the old one tested OK. The new one helped a little, but not near enough.

I have studied Brad Anders' site and can't come up with any other ideas of what to check. I have to believe the ignition system is fine because it runs so well when warm. I have checked timing and dwell and they are on spec.

Any suggestions out there?

[Porsche Rescue]

It pains me to write this..........and Rich Towle, Brad Anders and others are allowed to say "I told you so!"
To refresh memories, car very hard to start, very hard to keep it running until fully warmed and then it ran very well. I tested and retested all fuel injection components as per Anders web site, replaced head temp sensor (even though the old one tested OK), replaced coil, points, condensor, rotor, cap, checked timing. Removed the old Heathkit CD ignition. Nothing changed.

Then I decided to attack other issues (install ss heat exchangers, new Bursch exhaust) and since the exchangers were off it was time to replace the leaking push rod seals on #2. Upon finishing that task it was necessary to adjust valves on #2 so naturally I did them all. A much easier job without heat exchangers in place. Three cylinders were set at .004 (the PO had an old manual with incorrect spec of .004). One valve was even tighter than .004. Set all at .006. Put it all back together, with new plugs (but the old ones looked pretty good), and fired it up to check for exhaust leaks (I got 'em but that's tomorrows' project). Car started immediately, quickly settled in at about 2000 rpm just like it should. Didn't drive it because of the exhaust leak, but clearly my problem is solved.

Rich Towle, B. Anders and others repeated the common advice: before attacking the fuel injection, make sure that engine is in good electrical tune, properly timed and VALVES ADJUSTED. I procrastinated checking the valves, thinking I would get to it when I did the exhaust/seals. And besides, I was sure the car would not run so well when hot if the problem was valve settings. WRONG!

So, problem solved. Now, can someone tell me why tight valves would cause hard starting and very poor cold running, yet the car would perform well once hot? I would think heat would close the gap even more. But, obviously, I don't know nearly as much as I thought I did!

Now, how do I seat the ss exchangers so they don't leak!