Will wet crank sensor cause misfires?

[jasondelane]

I just put this motor in a couple weeks ago. It was running cold so I replaced the thermostat today with a stock 195 degree stant. It had a 160 in it. Anyways, in the process I spilled quite a bit of coolant and water on the front of the motor. When I got everything back together it started, but had multiple cylinders misfire and would not idle without dying. I've worked on it some this afternoon, checked all connections near the thermo housing, but have had it go from several cylinders out, to one cylinder and idling, to finally dying and not running at all. I pulled a couple spark plug wires and it gets a weak arc when I turn it over, and although I didn't use a gauge, there is some pressure at the schroeder valve. It did pull a p0352 code when it ran a while earlier, but now it's not doing any codes.

Could water have cause problems with the crank sensor, and would it still get a weak spark? Is it possible that the timing is somehow off all of a sudden. It seems like an electrical problem since it has varied from 1 to several misfiring cylinders. I don't know, it's confusing

1997 explorer, 98 engine. 5.0L AWD

 

[crazymind]

Try diconnecting the crank sensor the plug it back in. I don't think it getting wet will hurt it. I say this cuz I've ran threw some good size puddles and mine still ran fine. If you think its a week spark maybe your coil is on its way out the door. How did it run before you did the tstat change?

 

[jasondelane]

When I get home I'm going to check the crank sensor because it caused me problems when I put the junkyard motor in, specifically, the insulation on the wire at the connector was pulled back exposing the copper and shorting out, causing it not to crank.

I ran the truck for three weeks with the 160 degree thermostat. The thermostat was bypassing also which was causing it to take forever to warm up.

I'm pretty sure the coil is going out because the #4 cylinder is getting no spark from the coil anyways, and it was popping a P0304 code (misfire cylinder #4).

I'm thinking it the water and coolant may have been messing with those two uninsulated wires, but I would have thought it would make it not crank at all, and not just make it run rough as hell.

 

[jasondelane]

Update. Removed crank sensor and check KOEO voltage at connector. 1.5 volts on both wires. Cut connector off, checked continuity at connector and it's shorted. Checked voltage on exposed wires an still got 1.5 on both. Apparently the wire has gotten hot and shorted I'm going out now to take the crank sensor wire and connector from another harness and run it to the PCM connector pins 21 and 22 and that should solve the problem. I'll check in later with results.

 

[jasondelane]

This is frustrating

 

[jasondelane]

Both CKP sensor wires should have voltage. This is from a CKP troubleshooting flow I found during research.

2) Check For CKP+ Voltage Fault

Reconnect PCM connector. Turn ignition on. Measure voltage between CKP+ terminal at CKP sensor wiring harness connector and negative battery terminal. If voltage is more than one volt, but less than 2 volts, go to next step. If voltage is not as specified, go to step 19).
3) Check For CKP- Voltage Fault

Ensure ignition is on. Measure voltage between CKP- terminal at CKP sensor wiring harness connector and negative battery terminal. If voltage is 1-2 volts, go to step 10). If voltage is not 1-2 volts, go to next step.