Ok guys take me home.. I have been working this tpi motor swap for a year already smoked a motor from an big time fuel into oil dump. I know I checked before and thought I was good after running out of ideas and 1 day away from a " gasp " carb set up I put the tester back on and found this . Pump primes the rail imediately with 48 lbs and in 30 seconds im sown to 10 or less when i fire it up with gauge on it holds at 45 pretty steady . I checked the vacuum hose on regulaor it is dry. Bad injector/s ???? please say it is I know its expensive but im into this swap from several several K already .. Point me in the direction I need to go or could it be ecm faliure

 

Most likely the check valve in the fuel pump is leaking by, mine did that for years but never caused any problems.

 

Ohm out the injectors anyway. They should be more than 14 ohms when warm. Less than 12 and you have a bad one.

 

Its easy to do a leak check. First, have 2 vice grips ready, and look for your rubber hoses feeding the TPI. One should be from the tank, the other from the regulator back to the tank. Have someone key up the fuel pump, and then clamp off both hoses. If your pressure stays, its the fuel pump or regulator. If pressure drops, its the injectors. Most likely, your fuel pump has a bad check valve in it, just like mine did, and just like John from the post above. Mine lasted 2 years this way before it finally gave out.

 

I think its the new pump go figure

 

rob - how you doing? im looking to put my tpi onto my 305 instead of waiting for the 350 to be done.
i know i have to put in a retrun for the fuel - but where the heck does it go. i can drop the tank and put in a high pressure fuel pump - but where does the return line go. i figured i am going to play with some of my bolt ons before i put the 350 in.
eventually i will have to put the new fuel pump in for the 350 so might as well do it now.
any help?
thanks