A vapor lock issue?, Starting after 30 minutes or so of sitting Options

[boxsterfan]

So on my 74 2.0L D-Jet, my car normally behaves this way on cold start:

1. Starts right up and idles high while cold
2. As it gets warmed up, the idle "hunts" between 0 RPM and 1200 RPM and can occasionally die when pulling up to a stop sign (you might have to blip the throttle).
3. After she warms up, she idles perfect at 900-950 RPM.

The problem:

1. Car is warmed up driving to a store (idling perfect 900-950 RPM)
2. Go into store for 30 minutes
3. Start car (starts for a second but then dies if you didn't give it any gas)
4. Turn key off
5. Turn key right back on and it doesn't want to start (just cranks). But if you give it gas while cranking you can get her to start....almost like push starting the motor and popping clutch).

Note: My fuel pump is in the front. Stainless steel lines in the tunnel.

Am I still experience vapor lock?
Failing CHTS (also related to idle hunting)
Other?

[Tom]

From the owner's manual for the 75 2.0 :
Before starting, depress the accelerator pedal fully and keep at full throttle until engine runs.
The reason for this is as follows: when the accelerator pedal is depressed after the key is turned to the ON position, the ECU receives a signal to lengthen the injector pulse, effectively enriching the mixture.
So the engine is warmed up and driven for xx minutes and you go into a store for xx minutes and come back out and it does not want to start. The cylinder heads are aluminum and cool off at a different rate from the cylinders ( usually steel) and while the cylinders are saying- we are hot, give us a lean mixture, the CHT in the cylinder head is saying - I'm cooling off so give me a richer mixture. End result is an over rich mixture until the heads are warmed back up.
Back to depressing the pedal BEFORE turning on the key switch. If you fully depress and hold the pedal while cranking, the ECU does receive the enriching signal. It is similar to an accelerator pump on a carbed car except you can "fool" the ECU by depressing prior to power on. If you depress the pedal before the key switch is turned to ON, the extra rich mixture does not show up.
I corresponded with Brad Anders on this very subject back in 2008/9 and this is what he told me then. I have tried it and sure enough, it works! We talked about installing a secondary circuit that could be switched on manually to overcome this heat soak issue and he said at the time he was working on a solution, just couldn't find the time to get it worked out and tested. Basically one would need to add a parallel resistive circuit with the CHT and switch it on when you get in to start the car and turn it off once started.
Hope this can help with the understanding of our quirky FI system.
Tom

[swooshdave]

The cylinder heads are aluminum and cool off at a different rate from the cylinders ( usually steel) and while the cylinders are saying- we are hot, give us a lean mixture, the CHT in the cylinder head is saying - I'm cooling off so give me a richer mixture. End result is an over rich mixture until the heads are warmed back up.
Tom

I doubt the heads will cool off that much faster when sitting in a heat soak situation. I could be wrong but has anyone measured the difference? Won't the heads pull heat from the cylinders?