ok my turn

right the injectors are def +12v supply

on the tps get test metre and test between pins should be between top&bott pin(2000-5500 ohms)on pins 2&3(150-2000 ohms throttle closed then try same pins with throttle wide open(3500-5000 ohms) on pins 1&2 (4000-5500 ohms)

but if you have to let air into inlet manifold sounds like 1 of 2 things running too rich(coolant temp sensor,intake air temp sensor,fuel press reg)

or the idle speed control valve,basicly this is a air bypass valve that the e.c.u determins how long it stays open witch is singnal fed from the ecu from engine temp sensor this alows more air into the inlet for cold starts and when using heaters etc the revs dont drop to far down.this is basicly what u are doind by pulling of the pipe...

have u tryed keeping the revs up after i starts if so dose it smoke (black)

also the crank position sensor is worth a try too

tommy