Can fuel, fuel lines/system get so cold it causes an engine to stall yet later start?
 

Just figured I'd ask you guys about this...


can fuel and fuel lines get so frozen that it could cause flow issues and/or an engine to stall out dead?


the story...


Finished a top end engine rebuild on my 1995 2.5L auto jeep wrangler back in September (blew head gasket and warped the head) and its purpose is to be my beater and winter ride. it has been running great since then. up until 2 days ago.

it's been really cold recently in NJ here and will snow every few days and then go into a deep freeze. All the driving I've done on the jeep has gone well in the snow storms, I'm 99.99% in two wheel drive in the snow anyways. However with no front nose or low bumper cover, a LOT of snow from other vehicle's spray and from when my front tires are turned while driving gets sprayed on the underside of the jeep. when I say lots, I mean LOTS ! well two days ago on the way to work, I was low on fuel (about 1/8 tank) driving in a snow storm all morning and about 2 mins from work the jeep dies. not like stutters or anything, just cuts out. wouldn't start back up. I fiddled with a few things in the engine bay and all seemed ok, about 5 mins later it decided to start up. 13 hours later on the way home from work, it stalled again. No Check engine codes, nothing, just wouldn't fire. then it did about 8 mins later, (temps that day were around 16-20 deg)

today I melted and chopped well over 100 pounds of snow and ice from the underside of the jeep. ice that was frozen into THICK, DENSE masses around fuel lines, brake lines, brake calipers, steering knuckles, the front driveshaft, the transfer case, and even some that had completely entombed the rear half of my exhaust. used scalding hot water from a hose that I ran from the house, and also an assortment of pry-bars, screwdrivers, and pipes to dislodge all the ice.. when all was said and done I moved the jeep and cleared out 21 full snow-shovels worth of ice and snow debris that I removed from the underside (not counting the ice I melted with hot water in the tight crevices) . lots of it from around wiring that hangs low on the underside (o2 sensor, rear tail lights, crankshaft position sensor)


So my question to you guys is, could a fuel line, fuel system, fuel itself get cold enough by being almost completely encased in ice buildup that it could cause flow problems? I checked at the shrader valve this morning prior to any of the above and I had the proper 31 psi (vac line on) and 39 (vac line off)



or, did the chunks of ice put so much weight on some of the wiring to various sensors that they may have become stressed? crankshaft sensor especially.

or .... is it some other problem. I will be running diagnostic checks tomorrow on MAP sensor, battery, ignition coil, plug wires, fuel filter, camshaft position sensor and crankshaft position sensor just in case. Also, filled up on fuel today and added some HEET dry gas to the system. thanks guys for ANY input

Will gasoline be affected enough by those temps to impede flow? basically no. Diesel though, it would be possible.

gas does expand/contact quite a bit over change on temps. When i got gas at temps below 0 F, id gain 1/4 tank in my 95 grand cherokee once i got to areas of temps in the 40s.

You could be right about the weight of ice on wiring or ice got into connectors in the same manner an ice dam forms on the roof of a house.

There could also be water in the fuel, which always seems to be an issue during the winter.

When you lose fuel pressure, your engine will hiccup, stutter, and any other funny words you can use to describe it slowly dieing. When your engine goes from 5 stars to dead in the water, you are losing spark. Thinking like this, it was not fuel related stalling. I would consider a failing crank position sensor as a possible cause. What exactly was happening, I do not know.

Were you still rolling around on an 1/8 of a tank on the way back home when it stalled again? Certainly plenty of possible issues here but I would start by filling the tank to rule out crappy fuel (will be fun to drain if the pump is the issue).

Whoops, I meant to say something about that too. 1/8 tank on a yj is probably empty! Those sending units are as good as lt1 4th gens :rofl:

Running around on 1/8th of a tank on any in-tank fuel pump setup is asking for trouble.

thanks for the responses guys, yea, unfortunately I wasn't able to fill up that morning since the gas stations on my way to work are closed at 5:40 am when I leave to go to work. I had initially been ruling out a fuel issue because the engine just died... didn't sputter, or slowly cut out, just flat went off. again on the way home from work it did the same thing, even prior to me getting close to the first gas station. yesterday cleaning the ice out and today checking over all the relays, fuel components, ignition components etc.. I've found nothing wrong, torn, or broken. the jeep has been up and running as normal since chopping out all the ice, filling the fuel tank, adding dry-gas additive, and checking electronics and sensors. I'm going to have to keep an eye on this for sure..... and attribute it to ice buildup on the underside.. most likely a bunch of it hanging on the crankshaft position sensor wire at the bellhousing, causing it to trigger the engine shutdown.

and in my mind I knew my initial question was dumb about fuel lines and fuel systems getting "too cold" because I thought to myself, well vehicles in Alaska and Siberia wouldn't function, but I also thought being so low on fuel and the lines being encased in ice buildup for weeks might have caused a condensation blockage of sorts ... that's why I figured I'd ask you guys .

sometimes you just cant trust your own brain I guess...

Doesn't hurt to ask. Could have even been ice melting and entering a connector somewhere causing a short.

that too. highly likely

This is likely since gas floats on water. If it was allowed to sit long enough with just the right amount of water in the tank - it is very possible to have the type of problems Dave describes.

many vehicles in Alaska and other cold countries utilize block warmers and so forth, i understand this has nothing to do with warming the fuel, however it will inevitably keep engine bay temperatures a little warmer in turn keeping the fuel in the rails warmer and what not.

It does sound like more of an electrical problem and i would bet it had to do with the amount of snow underneath your jeep however, a friendly suggestion i might offer is, don't use "scolding" hot water on anything that's frozen or maybe extremely cold, I'm pretty sure that would be an easy way to break something. As we all know when really cold things come into contact with really hot things they can cause issues. Obviously if the ice was frozen on there that may have been the only way, but that's just my $0.02, hope you get it all figured out.

I know military vehicles having systems tested for cold weather in Alaska will not start if left outside, diesel does some wonderful things in sub freezing temps.

FYI, a block heater won't raise ambient air around motor or fuel temps in rails for that matter. On a 10-20* night it will raise ECT to around 75-90* pending how long it was on but its still a cold ass motor bay.

Our trucks would sit in sub-0 degree Fahrenheit temps on base at Fort Drum NY. Some had ether setups but most would just fire up and be loud and noisy as hell for the first 5-10 minutes.

I start up my dodge ram diesel in these temps, 10-20 degree Fahrenheit, with no issue and never plugged the block heater in. The starting instructions said just to hold the throttle at 1000 rpms for like 30 seconds. Most of the block heater are only designed to keep the coolant warm and therefore liquid. Antifreeze can actually freeze sometimes, especially if mixed with too much water, and that prevents it.

I also used to pump gas and diesel, In the winter, the diesel has an anti-gelling agent in it but a lot of guys do trust it and some truckers came in and would get a few gallons of kerosene added to the tank to avoid gelling.

Also a lot of diesels have a warmer inside the fuel filter. A lot of big trucks also have fuel warmers to keep things from gelling up. So far as gas goes its highly unlikely. But if you had enough water in the tank it is feasable