Still having problems 5.0L V8 1990 F150?

Question

I replaced the TP sensor, Idle air control, oxygen sensor, rebuilt the throttle body, and replaced the fuel relay. My 5.0Lv8 keeps stalling while driving and at stops. The code reader says primary and secondary fuel pump circuit failure, and low idle. These are the codes the code ready gave me after a check engine light came on... 44,13, 65, 41, 87, and 95. What should I do now? I forgot to mention I did replace the fuel filter the same time as the fuel pump relay and the idle air control valve. Also can someone explain a little on the TFI ignition and how it could effect the engine to stall.

Answer 1

Let's try a couple simple things.

1) Replace the fuse to the fuel pump. (even if it looks good)

2) Inspect the connections at the fuel shutoff inertia switch. (they may be corroded from moisture, or loose.

3) Make sure the fuse box junction is secure to the firewall.

4) Check your battery connections. Yes, your battery....

5) Double check your pigtails at the fuel pump electrical connections.

Somewhere you've got an intermittent open circuit. (not a short)

Answer 2

look under the truck inside frame drivers door there is probley the high pressure pump there,the late 86 to late 1990 had a low pressure pump in the tank and a high pressure pump on the frame.you need 60 PSI from the high pressure to run right,,if no pump than you have the high pressure pump in the tank late/late 1990 on..not much ether it sparks or it don't..id say one of the pumps is not working..take a pressure reading off the test valve on the fuel rail..if you have a propane torch put nozzle in the air intake (unlit of course) while engine running and see if the engine picks up

Answer 3

What about the electrical connections to the fuel pump? Maybe a bad fuel pump.

Answer 4

Could be a weak fuel pump or bad wiring