if i put a wire on the relay it runs but sounds week if i put the relay back in it dont run at all not when a turn the key on or off this if the relay is in and i hold the lift pump in my hand i dont fill nothing is happing???

 

No it only runs long enough to pressurize the system then pulses as fuel pressure drops off controlled by the internal monitor/chip as seen in this reference Lift Pumps & OPS operation and troubleshooting that said you also need oil pressure seen by the OPS to keep the lift powered up, if you vent the filter manager via the drain or the vent then pressure will not accumulate and shut off the pump when it is jumpered, you can use the lift to get the last or all the fuel out of the tank if willing to wait that long (remember the lift is a 28 gpH as in hour) delivery if healthy, btw purring does not mean it is capable of delivering fully ergo the lift pump test I recommend in the linked reference

 

On a 95 the LP relay only operates when the key is turned to the start position IIRC.
After that the OPS takes over power duties of the LP when pressure is enough.

Google OPS relay mod and add asap.

 

Ok but what controls the lp when the key is first turned to on. I keep hearing the relay runs it in cranking and ops take over after it's has 4 psi and running. Wha controls it to prime the system and runs is during driving . ? This site isn't very helpful esp because no body has any answers.

 

There is no LP prime cycle on a 95-there is no power to the LP when the key is in run on 95 and older trucks.

The only priming happens during cranking when the relay powers the LP,otherwise while the engine is running the OPS powers the LP.

You have been given the answers it would seem,accept what you have been told.

The prime cycle was only introduced with 96+ trucks.

 

This site isn't very helpful esp because no body has any answers.[/QUOTE]

Seriously!!!, you could have had your answer in 2 minutes from searching this site. Half the posts in this section are about lift pump issues.

 

Bring back a 3 year old thread and then say no one helps?