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Need some help! Driving today and the engine died on me and now will not start. She started up right away that morning. (had been sitting a while); I did notice a little sporadic idle but that leveled out after a short time.
As she ran fine before this so I am fairly confident its not mechanical (i.e. timing, plug wires etc - could be wrong though) and am guessing its electrical.
Where do I start trouble shooting? Thoughts? Thanks!
Ford 4.6 liter 4-cam Cobra mod-motor, Teksid block, stroked to 5.0 with new forged crank, H-beam rods, forged pistons; Electronic fuel injection; Accufab throttle body, otherwise stock intake, heads and cams
Ok so I decided to start with the crank sensor... So according to the Haynes manual the first thing you are supposed to do check to see if you have voltage to the sensor..but that is all the detail it gives.
In the key on position, I put the lead to both of the two wires... I got ~1.5V at each wire. This seemed odd to me. I would think one would be ground or a return wire (i.e. no voltage unless the sensor returns it to the ECU) Is this correct or does this indicate that I have an issue at the ECU or in my wiring?
When looking at the sensor its self, it was pretty dirty so I went ahead and pulled it to clean it up. And I noticed a possible issue close to where it mounts... see picture at the tip of the probe. Is that a hole where there should not be one!!!!!!??????
Thanks all - I am new to the Mod motor and the associated electronics. Enjoying learning as I go though luckily!
I can hear the pump prime when the key goes to the on position.
Just wondering if you ever found the problem, have a 2001 Ford Mustang GT 4.6 was driving and it just shut of. Will not start back tried to turn over but will not.
Ok so I decided to start with the crank sensor... So according to the Haynes manual the first thing you are supposed to do check to see if you have voltage to the sensor..but that is all the detail it gives.
In the key on position, I put the lead to both of the two wires... I got ~1.5V at each wire. This seemed odd to me. I would think one would be ground or a return wire (i.e. no voltage unless the sensor returns it to the ECU) Is this correct or does this indicate that I have an issue at the ECU or in my wiring?
When looking at the sensor its self, it was pretty dirty so I went ahead and pulled it to clean it up. And I noticed a possible issue close to where it mounts... see picture at the tip of the probe. Is that a hole where there should not be one!!!!!!??????
Thanks all - I am new to the Mod motor and the associated electronics. Enjoying learning as I go though luckily!
I can hear the pump prime when the key goes to the on position.
That voltage you're seeing is called a bias voltage. It's put out to the circuit through an extremely high ohm resistor, so pretty much anything plugged into it will pull that voltage down to 0. This is how trouble codes are set. If the computer sees 1.5v on that circuit with the key on, it will set a code for a circuit related fault. In that specific case you would likely think a dead sensor, but it's actially because you're testing unplugged. Always try to do voltage checks while the circuit is loaded.
05-30-2016, 09:13 PM
Engine died; now won't start - where do I start?
