1990 p/u won't start

I have a 1990 with a 2.5 tbi that won't start unless I dump gas down the throtle body. Then once it starts it won't Idle unless the map sensor electrical connector isunpluged. The only trouble code is code 34 map no sig, or high pressure. I have replace the map twice, the tbi base gasket all vacume lines. where should I look next?

I have a 1990 with a 2.5 tbi that won't start unless I dump gas down the throtle body. Then once it starts it won't Idle unless the map sensor electrical connector isunpluged. The only trouble code is code 34 map no sig, or high pressure. I have replace the map twice, the tbi base gasket all vacume lines. where should I look next?

Check the vacuum hose to it.
Does it have vacuum to it running?

did you unhook the battery to restart or reset the computer, after you changed out map? if not do so, it will erase error and set cumputer back to learning mode. only need to unhook neg side of battery for about 10 to 15 min.

yes, it has vacume while it is running.

Yep un hook the batt over night almost every night, still no help, I am replaceing the fuel pump currently, I used to have a fuel pressure gauge, but it dissappered, and about the same price as a fuel pump.