Cranks, only starts when starter fluid sprayed to throttle body

  • 1993 FORD RANGER
  • 2.3L
  • 4 CYL
  • 2WD
  • 100,000 MILES
Check fuse relays clicks when key turned and checked with light tester. Removed tank and tested fuel pump with jump box on terminals. But when I was under truck with plug that goes on pump and no juice when keys on. Could I not have a good ground on frame rail due to rust?
Do you
have the same problem?
Monday, February 22nd, 2016 AT 7:59 AM

1 Reply

You better not have voltage to the fuel pump if you are not cranking the engine. If you did, you would have a fire hazard if a fuel line got ruptured in a crash. You did not say if the engine continues to run once started with starting fluid. If if does, the fuel pump has to be working. Also, can you hear it hum for one second after turning on the ignition switch? If you can, it is working. In that case a failure to start could be due to low fuel pressure.

A better suspect if the engine continues to run is the coolant temperature sensor. Normally failures of those are unheard of because there is just one simple resistor inside it, but Ford managed to have a rash of failures in the early 1990's. The resistance value would bounce around confusing the Engine Computer into reading the wrong temperature. It could respond by not commanding a rich enough cold-starting mixture. You would have to read the temperature being reported on a scanner to see what the computer is seeing.

If you never hear the fuel pump run and the engine does not stay running once started on starting fluid, we will have to see if the pump really is not running. You must check for voltage to the pump while cranking the engine. If you do have 12 volts, plug the connector back in, then try to back-probe the ground wire. If you have voltage on that during cranking, you do have a break in the ground circuit.
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Monday, February 22nd, 2016 AT 9:13 AM

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