A side from the rez drama, what is the prognosis on the crawlabego
The current working theory right now is I have a crank sensor going open when hot. It’s got the later style sensor so I should not have an issue with it getting stuck when I do replace it. However some 8.1’s did have a phantom stall issue that kicked a lot of peoples butts and I think it was mine on the trip.
The problem is when the crank sensor fails, it stalls, like right now. Think just turning the switch to shut it off. No stumble. Just off. And since it kills the system, it will not set a crank sensor code. I did have a p0347 knock sensor code set, but that won’t cause a stall, but might have caught the knock slightly as it went down. Dunno.
Here’s what I do know. Initially the problem was fuel related. Engine stumbled just like it ran out of fuel. This I believe was self induced. In my repair to the exhaust hanger on the driver side I neglected to see the two weatherpack connectors for the sending unit could get close to the exhaust pipe. When we had no fuel pump on key on I found both connectors melted on the exhaust. Which is where I found no less than FOUR butt connectors hidden in the harness between the connector and the frame for both the fuel pump power and sending unit. Obviously adding some resistance into the mix. Spliced in fresh wire for both circuits and still had no pump. I did have voltage finally just the pump was smoked.
Tow to a shady spot off the main trail and swapped in the spare pump I had with me. Fired right up. So problem fixed right? Nada.
Next day after 30 miles off road I try to cross a crack and it stumbles like it’s out of gas again. Keep in mind we dumped close to 15 gallons in after the pump and the tank showed 3/4-7/8 on the gauge which has been reasonably accurate up to this point. No way did I burn 20+ gallons in 30 miles. Barely a half mile to decent graded dirt rides we ride tow strap some more. Unsure if we are out of gas Bill and my son race ahead for Big Water to grab more fuel. Andy was dangerously low on the rental too.
They meet us further down and I dump 12-13 gallons back in and give Andy the rest of one can. Showing full, engine fires right up. Of course while we are waiting I’m running every contingency down in my head. Did the regulator fail again and fill the oil pan with gas? Oil level was spot on full, no fuel smell. My fuel pressure gauge went doa so no confirmation there.
We make it to Alstrom point and decide to throw in the towel. I’m not risking it more and screwing up peoples vacation limping my broke truck all over the desert. Head home in the morning.
We take off the next day. Air up in Big Water and spend 45 minutes hooking my sway bar back up (stupid side quest I should have left alone, will explain later). More fuel in Page, only taking 8 gallons. Which the math wasn’t mathing. That’s my red flag telling me I’m not using extra fuel. I was curious from the day before and wanted to know if the tank would take a lot or a little to fill up. In this case 8 gallons for the ride in from where I added fuel the day before and all the driving after made sense.
So far running great. 1 hour down the road. Dead. Stumbling and died. Can’t confirm with my gauge, but cracking the fuel line at the filter proved there was residual pressure on the inlet side. I that’s where the filter came in. Sent Bill and Robbie inner another chase for filters. (Could not blow through the filter)
Put the fresh one in and it fires up. Cool we gone now! Not so fast. This time like the switch was off. Limp it to the next res gas spot and do a world record 3 minute filter change (same spot we changed Larry’s u-joint on the k10 last year).
Not five miles down does it die again. Like the key was switched off. Limp it further since it was showing 1/2 tank on the gauge. Rather than the 15 gallons in Jerry cans I had onboard being hot, let’s get cool fuel from another res gas station. Now it takes 12 gallons which check out based on the distance we covered.
After fueling up it stalled again in the same way but if we let it set a few minutes it always fired back up without having to cycle the key multiple times times as in a case where it lost fuel and had to reprime the system. We limped into Cortez this wat. The p0347 code was back and a cursory wiggle test at both knock sensors, cam sensor and map sensor wiring yielding no results. I could not find any damaged or compromised wiring that might be taking out the 5v reference circuit either.
That’s the long way around to say why I think it’s the crank sensor. Nothing else could cause it.
It will run without a Cam sensor. Not great but it will. Cranks sensor fails and the engine won’t run at all if it’s not generating the signal.
Have I looked at it yet since I got home? Absolutely not. I grabbed my duffel bag and the food out of it and left it where we parked it behind the garage. Had I looked at it this last weekend I might have thrown a lit match at it and watched it burn. My cup of frustration did runeth over multiple times. My son and the others did talk me down off the ledge but needless to say I’m not happy about it. The self inflicted stuff for one. The filter issue I knew about and since I never fixed my open evap line is why I’m sucking in garbage to clog the filter. Between that and the melted wires I know why this latest pump died. The crank sensor just being timed well enough to make me overlook it as a cause didn’t help.
I’m in lovely Lubbock Texas this week far enough away to avoid setting it ablaze. By the weekend I’ll have a new crank sensor in hand and see if I can sneak it out without removing the intake.