-30 and wont start

[winterbeater]

I'm trying to think where all the fuel is coming from? And I'm not getting any good ideas, just a list of possibilities.

MAP will make it run really rich, usually the MAP vacuum line.
The fuel regulator can do this, fuel will leak directly into the intake manifold.
Injector stuck open, usually one cylinder, which won't keep the rest from firing.
AIC stuck shut, but giving the the motor a *little* pedal will keep it running until you let your foot off the pedal.
Blocked airflow, something between the airbox intake and the TB. Which got me to wondering if an oil clogged air filter plus 0 degree temperatures (oil gets almost solid) could be blocking off the airflow (I've seen it with wet air filters).
Lastly, only seen it once, the charcoal canister is totally full of fuel and the fuel is running into the intake through the canister purge line. I pulled one charcoal canister that must have weighed over five pounds and was totally full of fuel.

I guess it is also a possibility the CPS is missing beats, what I think of as a CPS misfire. Not missing enough beats to completely kill the engine, but enough to get fuel buildup and plug wet fouling. You'd likely have to run it this way for a long time for much fuel to buildup and pollute your engine oil.

If you mess with the MAP vacuum line be very careful it has to be really brittle from old age and the cold. These lines rub through on the bottom from motor vibration, the MAP gets a good atmospheric pressure reference signal, but no (or very little) intake vacuum signal. The ECU defaults to full rich. The motor will/may run, but blow clouds of smoke and run very poorly. It can be hard to keep it from stalling.

I've been trying to think of something that would cause your excess fuel issues related to the cold. And all I'm getting is WAGs (wild arsed guesses).

The best WAG?arty:arty:

 

[8Mud]

I applaud Heahhash's perseverance, it had to be one cold SOB out there. I bought me a couple of 500 watt work lights (cheap on sale). With doesn't help my feet much, but sure helps the top half of my body.

Been there done that, I feel for you Bro.

I think I'm about half brain dead, my garage is so full of junk there is no room for the XJ. I freeze in the driveway and the junk stays warm.

 

[birchlakeXJ]

I agree with 8Mud; way to stick with it.

Hope you were able to keep your job!

 

[BulletMaker]

Congratulations! I'm sure if you're like me and will now have half a dozen replacement sensors on standby in case this problem ever comes back!

Time to take a victory lap... to somewhere warm like cancun.

 

[heshhash]

No to that point, but i do have a pile of new parts waiting to be installed.

 

[colafson]

EDIT: Didn't Realize you fixed the problem but I'll leave this info here too.

I had the same problem with my '86 Renix when it was -48. My FPR diaphragm was old and faulty I guess when it got cold it just cracked when pressure hit it.