I should have known better than to try one of those touch-free car washes. Grrr.... Right after the car wash rinse cycle, I put the truck in D to move forward under the dryer vents, and the truck just dies. At first it wouldn't even restart. After the 3rd or 4th attempt, the engine would fire but then would stumble, smoke out the exhaust, and then immediately die. Pushed it out of the car wash, popped the hood, found nothing out of the ordinary (the engine compartment wasn't even wet except for right in front of the fan shroud). Waited several minutes, tried to start it once more, and it finally fired up but refused to idle (the RPMs would drop too low if I let off the gas). Once the idle settled down, I cautiously drove off and then it was as if nothing had happened. Drove great, idled fine at stoplights, etc.

I went to run an errand on the way home, and when I came back to start the truck up (after a good 20 min), it fired right up on the first try but wanted to die unless I kept the RPMs up. The idle finally settled down and ever since the truck has been normal.

What happened? Wet coil pack? IAC going south?

In case it matters, I have a 2003 L w/ 46k miles. Stock injectors, TR-6 plugs.

 

Haven't had exactly that happen before; but, sometimes, when I pull out of a car wash, and get into the gas hard, it will just lose power like it dumped all the boost and stumbles. It doesn't do this any other time and only started doing it after I installed the whipple. I can turn the truck off, then back on, and it will run fine, as long as I don't tromp on it. After it dries out, everything is fine.

 

Check under the hood on the passenger side. Water can leak on to the wire bundle going to the ecu. This would cause your problem.

 

Water in the air filter?

 

Sounds Like a wet MAF...


After it rains I see a slew of vehicles that don't run right... clean off the maf, and they are right as rain... Use special electrical cleaner, not brake cleaner, as this will erode the electrodes..

 

also if you have a bad boot on a coil it can cause this same symptoms you describe, I know; it took me over a month to tract it down to an old and hard coil boot on the last coil on the passenger side. I remove the coil after a heavy rain to find that the plug cavity was filled with water grounding out the coil. replae the boot and no more problems... the boot had no visible damage, just slightly harder than a new one whic led to its inability to fully seal against the cylinder head.

 

That would be the ground wire too your fuel control module is corroded mine did the same thing after getting the under bodywash

 

What are you talking about? This thread is 14 years old, and Lightnings do not have a fuel control module.

 

I just hope that he is not a troll. It will be best for the moderators of this forum to closed down old threads.

 

2003 F150 XL 4.6L

Same issue, dies when wet. found this yesterday. Truck was running after hard snow, stopped for a bit and engine dies. Only thing wet on front of the engine. I had already replaced the cam sensor and the plug that goes to it, no help. This capacitor plugs into the ignition wiring harness so it may short to ground causing the ignition system not to fire. I'm not sure. Anyway, thought I would share. This one (there are two) is mounted to the front of the engine on the driver's side below the air intake, next to the valve cover. Hope this helps, both you and me. It's a pain when my truck won't start.

Capacitor PN - YL1F-18801-AA

 

so not even the same truck, and 2007 to 2022 is one hell of a jump