5KS Acceleration Problem (?)

[Henderson Nuuhiwa <hnuuhiwa@concentric.net>]

My '86 5KS is currently stumbling on acceleration when cold.  It starts fine
(no problem with cold start valve) and idles perfectly (so much for ISS),
however when the accelerator is depressed RAPIDLY the engine (when cold - not
at normal operating temp) will stumble badly, and in some cases die.  Also, the
response from the engine is delayed (depress pedal, nothing for about 3-5
seconds, then stumbling, and also popping sound from the intake side) and this
all occurs while under no load (in park).  On a VERY GRADUAL acceleration I can
get the RPMs up to 4000+ without experiencing these symptoms.

After the engine reaches normal operating temps, the symptom disappears,
(acceleration response is fine on a rapid - floor the pedal, and gradual basis)
......

Where should I start looking????

TIA

Henderson Nuuhiwa
http://www.angelfire.com/NuCommIntl/index.html

'85 BMW 735i (her car)
'86 5KS (my car)
'88 5KS (for sale)