2.5L ('98-'01) 2001 Ranger 2.5 liter No start/No spark

[BlackTipRanger]

In February I found that my truck would crank, no start. Just now I am able to start working on it. So far, on board diagnostic scanner will not connect to the system and cannot retrieve codes. No spark at the plugs, fuel pressure; yes. I replaced the crankshaft position sensor, replaced both coils, still no spark. I probed the power supply at the coils and get 12V at power and pulsing power to coils under cranking. I suspected that perhaps the Loctonics anti-theft device was fouling the system; disconnected that and reattached the ignition wire under the dash. Now, no crank at the ignition key. However, it cranks while jumping pin 30 to pin 87 on the relay in the under-hood fuse panel. Jump cranking produces no spark. Dead in the water, don't know how to proceed.

 

[franklin2]

After all the circuits and electronics, software, etc, the final stage is pulsing power to the coils. That is what makes the coils produce spark. If you have a coil on the bench, put 12v from a battery charger or battery on the + of the coil, and then hook a short wire to the negative of the coil and tap it on the negative of your 12v supply, each time you tap it, you will get a spark.

It doesn't make sense if you have pulsing power on the negative of your coils, that you do not have spark unless the coils are bad, or the sparkplugs are fouled with fuel, or there is something wrong with the sparkplug wires.

 

[BlackTipRanger]

Sorry, no not pulsing to the coils. What I should have said is: Coil pack power (red/lt green wire) 12V, PCM trigger wires (tan/orange and white/lt blue) attached to the coils were back probed and pulsing voltage during cranking.

 

[franklin2]

Sorry, no not pulsing to the coils. What I should have said is: Coil pack power (red/lt green wire) 12V, PCM trigger wires (tan/orange and white/lt blue) attached to the coils were back probed and pulsing voltage during cranking.

That is correct. Solid 12v on the + side of the coil with the ignition on, ignition module/PCM pulses the ground of the coils making spark.

 

[BlackTipRanger]

I have the Loctronics uninstalled and the under dash wiring back to the stock configuration and there was a burnt fuse for the clutch position sensor. Now I have crank at the key but still no spark. I'm going to recheck a spark plug on each side of the motor while plugged into a different engine and test them for spark again. Then I'm going to retest all the ignition circuitry from the new crank position sensor to the coils and recheck fuses. I also swapped around the relays under the hood and they all check out. Not sure what to do after that?

 

[franklin2]

Sounds like a solid plan. If it doesn't make sense, re-check everything. If nothing rears it's head, go inside the house and do something else, and think about it some, and then go at it again.

 

[BlackTipRanger]

Yes, thanks franklin2, solid advice. There is never a shortage of other things to do.