Need a 5-OH whisperer

[marshall_mosty]

Try changing out the main relay.

[drecords]

Try changing out the main relay.

Talking about the EEC relay? -- I had one in the spares box which I tested and confirmed working (12V applied across the coil resulted in 0 resistance across the ignition wire) and installed.

[Alien]

#1. Pump primes, pressure comes up to 40 then falls back off to 0. This is what has me confused, I have no spark and seems no signal for fuel pump to remain on. CEL illuminates which indicates comp has power.

How does the FORD Vats/Pats whatever work? Isn't there something funky about it being really difficult to bypass on the 5.0, integrated with the fan control or something silly? IIRC, GM has a ground for the fuel pump and a signal to ecm for the injectors.

[ShadowBolt]

This is most likely not your issue but several times I have had my 4.6 not want to start (even though it was turning over fine) after sitting in the off season because the battery was down just a little. I sounded like it was plenty hot listening to it spin the starter but for whatever reason it would not get any fuel or spark. In the case of the 55 the fuel pump will not even prime when I turn on the key unless I have over 12 volts. After charging the battery to a full charge it will start just fine. I even tried push starting once and with the battery at 11.5 volts it would not start.

JJ

[marshall_mosty]

How does the FORD Vats/Pats whatever work? Isn't there something funky about it being really difficult to bypass on the 5.0, integrated with the fan control or something silly? IIRC, GM has a ground for the fuel pump and a signal to ecm for the injectors.

Ford EEC-IV (87-95) didn't have VATS/PATS. The injectors and fuel pump relay both rely on the computer to ground the circuit, which is why the grounds are so important...

[drecords]

This is most likely not your issue but several times I have had my 4.6 not want to start (even though it was turning over fine) after sitting in the off season because the battery was down just a little. I sounded like it was plenty hot listening to it spin the starter but for whatever reason it would not get any fuel or spark. In the case of the 55 the fuel pump will not even prime when I turn on the key unless I have over 12 volts. After charging the battery to a full charge it will start just fine. I even tried push starting once and with the battery at 11.5 volts it would not start.

JJ

Jerry, I've had the same issue with #34 on the dyno....no start due to dying optima. I've had it sitting on a tender since TWS so battery should be optimal.

[drecords]

Ford EEC-IV (87-95) didn't have VATS/PATS. The injectors and fuel pump relay both rely on the computer to ground the circuit, which is why the grounds are so important...

When I pulled the computer last night I checked resistance to ground of pins 40&60 which are the ground pin and got 0 ohmses

[Fbody383]

I've had it sitting on a tender since TWS so battery should be optimal.

Unless the charger or battery is bad. Voltage?

[mach1]

I followed my troubleshooting guide and it said "Replace Windsor with LS engine", not sure what that means??

[Pranav]

I followed my troubleshooting guide and it said "Replace Windsor with LS engine", not sure what that means??

Fixes everything.