92 Ranger 3.0 No cranks, stumbles, dies.

[Madracingalley]

So I have a 92 3.0 Auto 2WD Supercab with 70k/Miles, in front of me. Drove perfectly fine one day. No start the next morning. KOEO jump test shows a 1-1-1 [all clear]. You can hit the starter, it will attempt to start but as soon as you let off the key it shuts off. Fuel pump is brand new [Delphi] and pulls 40psi, holds 40psi for awhile, not seeming like a fuel issue. Compression numbers are around 160 across the board. Spark is sparking, Ignition control module replaced with new Fomoco unit. Unplugging MAF does nothing. Any leads in diagnostic flow would be greatly appreciated.

 

[franklin2]

Hold the accelerator to the floor and then crank it. See if it clears it up. Some of these engines are easily flooded and the plugs can foul. I suppose Ford recognized this, in the computer programming they put a "clear flooded engine" mode. If the TPS shows the throttle wide open, and the rpms are low, holding the throttle open will turn the injectors off to help clear out the flooded condition. I have seen a perfectly good engine not fire at all because the plugs were fouled.

If you want to manually check this, pull a sparkplug and smell it and look at it. After cranking and not starting it will be wet and smell like gas. You can pull them all, use some brake cleaner and a wire brush and clean them up and try it again. But sometimes the throttle wide open method will work also.

 

[SenorNoob]

Why does this make me think ignition switch? Like the PCM relay is only on when starting maybe? Shouldn't be too hard to check with a multimeter and maybe an extra pair of hands.

 

[Curious Hound]

I agree with senornoob. Make sure the ugnitiin switch is working right.

 

[RobWigglezz]

Does the 92 use the key switch that uses a rod down the column? That rod goes to a connector and switch that is crimped together. They can come loose and lose connection with the connector and cause weird random issues.