84 VW Rabbit GTI - Hard to start when hot

Regarding my recently aquired 84 VW Rabbit GTI - manual trans - 8
valve.

I have read posts regarding topics relating to hard, hot starts but
have some additional questions.

The car starts fine when it's completely cold, but takes quite a lot of
cranking in order to get it to start when the engine is hot. I checked
the cold start injector and found that it is working as it should on a
cold start (sprays for about 8 seconds, then stops). However, the cold
start injector does not operate at all on a hot start. The car does a
"hot start" when I manually put 12 volts to the cold start injector for
a few seconds while a helper starts the car.

The other posts suggest that the failure is in the "hot start relay".
I can not find a hot start relay on the car, or referenced as a part
for this car. The only thing close is the CIS/Lambda relay. Is that
it?

I am about ready to add 12 volts directly to the cold start injector
via a switch or, timer relay.

Any suggestions?

Thank you in advance!

Jeff