Won't start, good battery.

[FordTechOne]

Same thread, different problem. My electronic keyfob intermittently won't "talk" to the car. First time it happened, three weeks ago, my car was locked and I had to get a tow truck driver to get the door open (cool airbag trick BTW). Once the door opened, voila, the key started communicating and the car started. Dealer looked at it and couldn't replicate the problem.

So, instead of leaving it with them for an indeterminate troubleshooting period, I took it home, and started leaving it unlocked. All was fine until I went to get in it to go home yesterday and it wouldn't start. The green light showed on the start button, but when I pressed it, I got a message that said "KEY NOT DETECTED". Only way I eventually got home was to use the emergency key location in the console.

Anyone else seen this?

Yes. Typically caused by Radio Frequency (RF) interference from non-factory/aftermarket components like alarm/security systems, audio equipment, and remote start systems.

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[duckydave]

I've always seen loose plugs burn up :-/.

Thats because of arcing between the contacts
if the contact points are loose they will arc
think of your battery when you hook up the terminals if you have something turned on the terminal will arc
if you have a loose fitting connector it will continuously arc and burn pu

 

[oesman]

Thats because of arcing between the contacts
if the contact points are loose they will arc
think of your battery when you hook up the terminals if you have something turned on the terminal will arc
if you have a loose fitting connector it will continuously arc and burn pu

You and DrElectron may be right. I only know enough to be dangerous. I employ a few electrical engineers and electricians for maintaining MCEs.

At one facility the way we always saw burnt plugs was via a small piece of software I wrote that monitors power distribution over SNMP and logs phase voltages, currents, active/apparent power for pf, etc... I hired a good controls person there and it's all in Johnson Controls software today. But back when we first got the facility we'd see an alert for out of whack (low) voltage on a phase and one of my electricians would go check it out, find a burned up plug. They were pretty shitty plugs we inherited at this one facility, wouldn't be surprised if they were from eBay/Alibaba. New plugs haven't had this problem since we've owned it.

So as a result I always thought that it was due to increased resistance, i.e. the resistance of the air or just poor contact. Sort of like an incandescent light making heat/light as a resistive load. Gonna ask one of my guys Monday and probably feel stupid .

 

[DrElectron]

Thats because of arcing between the contacts
if the contact points are loose they will arc
think of your battery when you hook up the terminals if you have something turned on the terminal will arc
if you have a loose fitting connector it will continuously arc and burn pu

Loose spark plugs burning up is NOT caused by electricity or "arcing". The spark plug is supposed to arc when working normally. The arc is the spark. In fact, if the plug is very loose, you might not get any spark because the plug gets grounded through the thread in the cylinder head. You can prove this by just taking a plug and connect it to a spark plug wire but don't let outside electrode or thread touch anything. Start ignition and you will see no spark. Let plug thread touch engine (ground) and spark appears.

The reason a loose plug burns up is because air is entering cylinder and leaning out mixture. Running lean increases cylinder temperature and burns plug.

 

[oesman]

Loose spark plugs burning up is NOT caused by electricity or "arcing". The spark plug is supposed to arc when working normally. The arc is the spark. In fact, if the plug is very loose, you might not get any spark because the plug gets grounded through the thread in the cylinder head. You can prove this by just taking a plug and connect it to a spark plug wire but don't let outside electrode or thread touch anything. Start ignition and you will see no spark. Let plug thread touch engine (ground) and spark appears.

The reason a loose plug burns up is because air is entering cylinder and leaning out mixture. Running lean increases cylinder temperature and burns plug.

Err not talking about spark plugs. I was talking about plugs that go into receptiles like L21-30Ps and Rs.

 

[DrElectron]

Err not talking about spark plugs. I was talking about plugs that go into receptiles like L21-30Ps and Rs.

Sorry, my bad. Yes household receptacle plugs will burn up if you have connections that are not clean and tight. A loose connection that looks like a small resistance will dissipate power across that connection. On the flip side, if the resistance is high, you get no heat. For example, when you unplug, resistance is infinite and you have absolutely no heat.

 

[oesman]

Sorry, my bad. Yes household receptacle plugs will burn up if you have connections that are not clean and tight. A loose connection that looks like a small resistance will dissipate power across that connection. On the flip side, if the resistance is high, you get no heat. For example, when you unplug, resistance is infinite and you have absolutely no heat.

Yea that makes sense. Saw (read as: had to pay to replace) a rash of burned up plugs at a facility, these were the twist lock 30A 3-ph 208 Wye.

 

[GT Pony]

Checked the 3 bolts on the starter today (5.0L GT) while I had the front end up for an oil change. Torque spec is 18 ft-lbs: http://www.mustang6g.com/forums/showthread.php?t=66799

I was able to get a 3/8" drive torque wrench on all three bolts with the right extensions. Bottom bolt didn't move at 18 ft-lbs, but the top two both moved about 1/2 a turn with 18 ft-lbs.

Worth checking those bolts if you're ever under the car and have access.

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