Quick question for you guys. i just put a 89 tpi in my 88 chevy truck and something dont seem right to me. when i check fuel pressure with a guage it will come up to 36psi then imediatly drop to 0psi with in seconds. now to me this aint right and i have a internal leak some where in my fuel system. to me the fuel pressure should stay and if it does bleed off take minutes if not hours. what do you guys think. i just need to know if im right or if these tpis are different from the newer fuel systems i have checked in the past. please any help is appriciated. thanks

 

Correct.
If pressure dropping immediately then faulty check valve on pump , regulator leaking or injectors leaking down
If injectors leaking that should be obvious from rich cond on startup ( exh smoke )
You can determine which by building rail pressure then alternatively clamp supply and return lines to see which one holds pressure after pump off
If pressure holds with supply line clamped then you know check valve is at fault

 

hey man thanks for the reply ill def try that out in the morning and let you know what happens. thanks again much appricated

 

Maybe your reg is leaking , you should be seeing more fuel pressure.
Something like 45psi with the vac line disconnected /
39psi @ idle with vac line connected