i have an 88 t2 it has 69k on it.. i put exhaust on it and the fuel cut switch from racing beat.. it ran fine for the most part for a while... but now i start it up.. 1600 idle and it runs decent besides that for about 20 mins then it falls on its face, like you cant move the car barely at all. im talkin 15 mph is pretty fast in this case.. new plugs , fuel pump, i did remove the emissions as well
hellp

 

water thermo sensor in the back of the water pump. green connector.

$20 at auto parts store

 

vac leak. check tps.