2000 Explorer LS 4.0L OHV Need Help!

[etinkerer1]

Check Engine on, getting P1507 error code, engine idles very rough, stalls when cold, bucks and jerks while driving. Problem is apparently the IAC valve, wiring, or something like that. Where is this thing (IAC valve), where is it mounted, and what does it look like? Can anyone post a photo with their reply? Is it that thing on the left side of the intake tube just downstream from the throttle, that looks like a gear motor, with a knob coming out of it? Please help!

I'm also getting P0305, cylinder 5 misfire detected, put in new spark plug set, gapped about .054" per sticker under hood, wires look ok, reading about 6k ohms on all. New fuel filter installed too. Could it be possible water droplet inside #5 fuel injector? Hate to think one coil inside coil pack is going bad.

 

[BrooklynBay]

Welcome to this forum! You are correct about the IAC valve. It has 2 small bolts holding it. Check the ECT sensor too. This picture of the IAC valve is from Karl Burns' photo gallery:

 

[James909]

A cylinder misfire is most commonly caused by a bad plug or a bad wire. Since you've already changed out the plug try swapping the wire with the cylinder next to it. Then if the misfire follows the wire that's your problem, if the misfire stays with cylinder #5 then the problem is elsewhere.

 

[etinkerer1]

I haven't been to school on this engine, don't have a Haynes manual readily available, so I'm flying blind. Got the photo of the IAC valve. I did find a couple of rotted out hoses from the EGR valve tube up to what looks like a MAP sensor below the IAC valve, replaced those hoses a week ago, reset codes, but they came back in a couple of days. What is this other (ECT) sensor you mentioned, what does it look like, and where is it located? I'll try swapping out the spark plug wires tomorrow. #5 and #6 should be same length. Thanks!

 

[BrooklynBay]

This chart is in # 25 in my list of useful threads:

 

[etinkerer1]

OK, but I'm not getting codes P0115 thru P0119, which relates to Engine Coolant Temp. I'm running a 180* thermostat, since temp gauge reads over 75%, almost into the red zone with a 195*. With a 180* it reads about halfway when hot. Just for laughs, I'll check it. Is that the one on the front of the right cylinder head, up on top?

 

[Sams01XplrSprt]

welcome what kind of explorer is an ls there is no such thing as an ls or are you talking bout xls.

 

[etinkerer1]

Update:

IAC valve was stuck, pulled it off, loosened it up with penetrating oil, small screwdriver and needle nose pliers, cleaned and flushed with jet spray Gumout, and oiled with 5w-30 Mobil 1 oil. That got rid of P1507 error code. Apparently what I thought was a knob on it is actually a breather cap.

Still puzzled with P0305 code until earlier today. Went to swap wires #5 and #6 on both ends when I removed the boot on the brand new #5 cylinder spark plug and saw what looked like a crack lengthwise in the insulator, on top.

Removed the plug and lo and behold there was a large piece of the insulator missing on the blind (lower) side of plug, and a gap about 1/8" wide running the length of the insulator. A small piece of the missing section of the insulator was still laying on the cylinder head in front of the spark plug hole. I still have the old plugs so I picked out the best looking one, verified the gap at .051" & reinstalled. Engine sounds & runs a lot better now, should hold until I get a new platinum plug again. They are $4.68 each at Advance, plus tax, so I hope they will be able to exchange the one that failed, under warranty.

This code (P0305) had me going. I was scratching my head for 2 weeks. Why I would be getting this code with a brand new spark plug, gapped to factory spec, when it went away when I regapped the old plug, before buying the new one? Until today when I found out the insulator on the new plug had failed. Why it just HAPPENED to be the EXACT #5 plug, I'll never know. Maybe Dr. Murphy at work. Strange coincidence! Problems like that can drive you CRAZY if you don't retrace your steps!

It is an XLS, I was looking at the passenger side door, where the "X" was missing, so it appears as "LS". It's still there on the driver's side door.

 

[Cobraguy]

99.9% of the time you have a broken plug when installing new plugs is due to improper installation. Did you use an actual spark plug socket? And you don't hammer them down tight. You just snug them up good. About 15 lbs ft of torque if I recall. It's not a lot. Wrong socket with just a bit too much torque at the wrong angle will always get you a cracked plug.

 

[etinkerer1]

I've cracked plugs off before on other engines as a result of not keeping the socket perfectly straight, but in those cases, the insulator broke crosswise, not lengthwise. I used a 5/8" spark plug socket with rubber insert and hex end, I had to use a 3/4" socket over the hex end of the spark plug socket for extra reach, because of the tight quarters. I did nothing different on the #5 plug than I did on the others. And the other five plugs are fine. It's just one of those freaky things.

The plug insulator was actually split lengthwise, like the top connector was either too tight when the plug was manufactured, and the insulator actually started to crack when that was pressed in, or the resistor core somehow expanded when the plug got hot, because moisture wasn't baked out of it or something during manufacture, and the insulator ruptured lengthwise when the moisture in it expanded with the heat. That could explain the 1/8" gap on one side, created when that section of porcelain blew out. Or maybe the plug was dropped on the floor, landing on its top connector inside the box, on its way to, or at the auto parts store. The engine ran great for about a week before the problem appeared, getting progressively worse.