External fuel pump pressure, running bad

[Terry]

I have an 1987 ranger that I pretty much built. It has dual tanks. It started running like it was loaded up or starving for fuel. I checked the codes and got a 95. I cleaned up the grounds like has been suggested. I also tested the fuel pressure. It is running on the low side 29 psi. I changed the regulator and the filter. It did not improve. I disconnected the vacuum line from the pressure regulator and tested it again. I got 36 psi that time. I think unregulated it should be over 78 psi? I tested it on both tanks and got the same results. I have a new high pressure pump in the box that have not been put in??

 

[alwaysFlOoReD]

The in tank is a low pressure unit. The external high pressure should be 30-40 psi.
I'm not sure where the psi goes unregulated.

 

[RonD]

FPR(fuel pressure regulator) on 1997 and earlier Rangers is set at 43psi max, no vacuum hose attached
So you are fine with the numbers you are seeing

Fuel pressure under 15psi would cause running issue, I can't see 29psi dropping that low even under high demand

Yes, the in frame pump could exceed 80psi with blocked return hose

Code 95 is an electrical issue, as you surmised
The computer monitors the 12volts being sent to fuel pump when it closes Fuel Pump relay, code 95 means that its wasn't seeing that 12volts all the time when it should have been


Exhaust blockage can cause what you describe, if air(exhaust) can't get out then new air(with fuel) can't get in so engine struggles to run, feels like its running out of gas..............because it is, new air with fuel can't come in
You can use a vacuum gauge to test for clear or blocked exhaust

 

[Terry]

My exhaust is all less than 3 years old. From the heads back. The cat is old. With a vacuum gauge gage hooked up, it is in the normal except during idle. It stumbles off idle and lacks power. I disconnected and plugged the vacuum lines going in and out of the filter box in front of the iac. I have a ecm that is for no egr and the egr and it is blocked off. I also disconnected the charcoal canister and blocked the intake on the throttle body. It acts like it is loaded up. I have not pulled the plugs and looked at them. I had a bad icm before but it did act like it is now. I'm not ready to take it to the shop just yet but It is confusing me. When I built this truck a few years ago, the guides seemed pretty tight. I put new valve stem seals on and hand lapped all the valves.