Pls help, fuel pump frustrations.

[BP68]

Hey all, I really needs some advice.

I have a 68 C10, running a 89 Suburban TBI bottom end with a comp cams camshaft (referred to as a 270 ?) Cast iron Vortec heads and Edelbrock 650 cfm thunder series avs carb and edelbrock intake.

My block was not bored thru for a mechanical fuel pump push rod, so I first went with a Jeg rotoray vane style pump with sep. regualtor. Set at approx. 5.5 psi. Pump was noisy but seemed to work. I have a blazer tank mounted in rear frame rails. Jegs pump was under cab in frame rail about center of door area. Just now getting truck road worthy. After doing some tuning and some WOT test, found pump seemed to be getting hot. Also seemed to be losing voltage. I installed a the fuel pump relay from the 89 suburban.
Pump started acting up again, found 12v and good ground into pump, but no pressure/flow. Pump seemed bad.

Did some reading and got a Master E8153 "canister" type pump. Rated at 13psi max for TBI application. I placed this pump at very rear of frame just forward of the crossmember where tank is mounted in frame rail. I think I read this pump is supposed to be better and self priming, since mounting below tank level is not really an option for me.

Everything seemed great, did some short test drives near work and made trip to gas station and lunch. Planned to drive home today.

Started her up, ran about 1 minute and shut off. Restarted and I was showing maybe 2 psi, then slowly dropped to nothing. I rechecked my ground connection, got truck running long enough to put on rack. Checked my relay, bypassed relay as test after truck died again. Had 12volts going into pump. Pump did not feel hot or like it was working at all. My battery is under the truck on frame, so I ran jumper wires straight from battery to pump power and ground wires. Nothing, no sound, no pressure, did not feel warm.

Everything seems to point to a bad pump. The new pump is about 2 weeks old with almost no run time. (two very short trips - which went fine) The old Jegs pump had been on there a few years, but until now the truck was only started and shut off, or moved short distances.

Just seems odd to me. Any advice. Yall agree it is prob. bad pump ?

Anything wrong with my mounting. Blazer tank is mounted to rear frame rails, with bed brace notched above for clearance. I have a vented cap as fars as I know, the filler vent is connected to the tank vent nearest the filler, the hole to the left of that is plugged and the vent on passenger side is open (planned to later get the motorcyle type vent that allows air in to prevent vacuum, but not out.) From there 3/8 rubber fuel line is feeding from sender to pump Maybe 1 1/2 ft of hose. Then rubber line from outlet of pump to 3/8 hard line to regulator on frame near right front of motor, then up a braided line to fuel filter (which is clean/clear) to carb.

From what I understand, guys run this pump on TBI conversions in a similar manner without issue???????????