Cold, Fuel, Spark, no Fire?

Greetings from Edmonton. Sadly my XJ isnt liking the cold one bit. Saturday the temperature here dove to a chilly negative -30 C. Thats around negatve -25 F or so. As my luck would have it, my XJ was never fitted with a block heater (First on the list for spring) so when it was sluggish and wouldnt start Saturday morning I wasnt all that surprized. I brought in the battery and charged it, tried to start later in the day ( temp had rose to a cool negative -17 C at that point) but still no go. So I brought the battery back in, let it charge overnight and was back out in the morning ( up to - 14 C ) Now we have had these temps ( -15 to -20 ) all last week and the ol girl started up every day, all be it a tad sluggish. Not today though. So I started with the basics, checked the fuel rail to make sure the gas wasnt frozen, which it was not, shot out of the release valve with a good spurt, so im assuming my pressure was ok. next onto spark, removed a spark plug, it was damp ( not soaked) with fuel, put it up against the block and had my wife turn over the engine and voila, there was my spark. I did notice however that the plug had ice on it just after the thread towards the gap end. I checked a couple more plugs and they had spark as well. Now Im at a loss, I removed the breather hose from the throttle body, made sure the valve was opening and still no start!!!! So off and walking to the Partsource I went, picked up a new cap and rotor, plugs and some quick start. Changed the plugs cap and rotor, tried to start but no go. I removed a plug, again i could see and smell the gas on the plug. So i tried the quick start and still nothing. So I have fuel, i have spark, and air seems to be moving through, so what gives? Is it possible that its just too cold for her? I tried to get a CPS at the part source but they need to order it in. But if the CPS was bad wouldnt there be no spark at all? Tomorrow Im going to try to ohm out the coil, just to be sure im getting enough spark. Any other ideas guys?

sounds super flooded to me, try pulling all the plugs, pull the intake hose, and jam the throttle plate open with somehing(this might not be of any help on a dry intake),crank it over some and let it vent.re-install the plugs and cross your fingers. We had around -20c weather and been getting a LOT of service calls for flooded engines,

short trips without letting the engine completely warm up is bad too when its that cold

Will give that a try tomorrow, im hoping it starts so my wife can make it to work. When I changed the plugs out they were obviously bone dry upon inserting them, I would think I would have at least gotten a chug or 2 out of it, but it didnt even hic up, just turned over and over. I was leaning towards perhaps a weak spark? spark was arching across the plug, but perhaps it isnt as strong as it should be?
At this point Im willing to dance and chant around it if it will get her to at least chug a little lol

88klaws88 said:

Will give that a try tomorrow, im hoping it starts so my wife can make it to work. When I changed the plugs out they were obviously bone dry upon inserting them, I would think I would have at least gotten a chug or 2 out of it, but it didnt even hic up, just turned over and over. I was leaning towards perhaps a weak spark? spark was arching across the plug, but perhaps it isnt as strong as it should be?
At this point Im willing to dance and chant around it if it will get her to at least chug a little lol

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hope you get it running! I had to block off my grille today, jeep would not warm up! stupid cold!

One more factor to the equation. Spark + fuel + compression. Learned the hard way. My son has a POS Fiero that ran until one cold day in winter. Spent a week screwing around with fuel, spark, timing, etc. Everything seemed good, but wouldn't even kick. Checked compression. Don't remember numbers any more, but it was down around 100PSI (I think). Anyway, put hone job and rings on it and it ran again. Wierd part ws that it seemed to run OK until it wouldn't run anymore on that cold day. Do you have access to a compression tester?

You need a strong, snapping, blue spark to start the engine. Yellow/orange means weak spark which may not be enough to start your engine, especially in the temperature your XJ is in. Test your coil for primary/secondary resistances to be sure. Gotta have a top notch spark for those extra cold days!

A new set of plugs may be a good idea if they've been in there a while. Simple stuff first. As you have spark, I don't think the problem is your crank sensor.

May want to have your battery "load tested" as well to be positive that it's up to the job. You can have a battery that is strong enough to crank the engine but not start the engine. It happens. How old is your battery?

I know you plan on installing a frost plug heater this spring but another option to consider in the interim would be a heater that goes on the oil pan or a dipstick heater. They aren't my favorite type of heaters but anything you can do to warm things up a bit before cranking will help. Or just find a warm shop and get that frost plug heater installed ......lots of winter left and this certainly won't be our last cold snap (It's -21 farenheit here in central MN right NOW) so I speak from experience! Good luck and post back what you find!

well i rechecked the spark this morning, nice and blue. Plugs, rotor and cap have all been changed. After attempted start up both with and without quick start, no fire. Its warmed up to - 10 C this morning, engine turning much faster, and funny you should mention it Birch, I got one of those magnetic heaters yesterday for the oil pan.
Checked the sparkplugs and they had a gas smell to them, not soaked, so I still have fuel, still have spark, still have no start. I havent touched the distributor at all other than the cap, so timing should be fine. Im running out of ideas here.......

I dont have access to a compression tester, but Im beginning to think thats all I have left to fall back on...... maybe my jeep has just had enough....

NEW DEVELOPEMENTS!
Well she stll wont start, but i was turning her over and she was turning really slow, I noticed some smoke/steam coming up from the hood. took a look under and found my starter was hot as hell. Ground at the battery very hot as well. So is it possible my starter is going and caused all this trouble or is it possible the engine or a pulley is seized? the belt and pulleys turn when attempting to start however. Someone has to have an idea..... anyone???

I doubt that anything is seized. You have to isolate and repair the starting circuit and get that back to snuff as job #1. Check for approx. 12 volts at the starter with the key on. If it's there and the starter isn't cranking well, I'd pull the starter and get it bench tested; may very well need to be replaced. This starter issue could be related to your problem; your engine has to spin at a certain level before it will fire up.

You're probably cranking it for too long. Starting circuit should only be cranked for 15 seconds or so and then wait for a minute. Make sure the gound at the battery is polished clean. Borrow/rent a compression tester. Here in US, Murrays lets you buy it, use it, and return it (so it's free). Most auto parts can test starter for free.

Ok another Update. She finally started today. its up to 0 ( bout friggin time) I took 3 days off working on her, was just too frustrated and Im doing all this out in the driveway in - 15 average temps . Went to a U Pull and grabbed a starter, and an IAC just to change them up. After starter install I tried turning it over, just got clicks ( battery was fried ) but became so frustrated I gave up. So today I changed up the battery with the one from our rv, installed the IAC and tried starting to find no spark. I had the coil out a couple days ago and tested the resistance to make sure the spark I was getting was ok. it all checked out. So I removed it again and gave the coil connector on the ICM a bit of a pinch and scrape to make sure I had a good connection, reconnected and got spark back. hooked the wire back up and she fired right up. So was it the IAC? Bad Spark? Starter? Was she that frozen? I dont know, next really cold day should be the tell tale sign. Im happy to see her purring again however. Any ideas anyone? Oh and by the way, thanks to everyone that contributed to solving this problem. Just wish I knew how i fixed it!!! LOL

88klaws88 said:

So I removed it again and gave the coil connector on the ICM a bit of a pinch and scrape to make sure I had a good connection, reconnected and got spark back. hooked the wire back up and she fired right up. Just wish I knew how i fixed it!!! LOL

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If you didn't have spark BEFORE you freshened up the electrical connection on the ICM, and then you did have spark, that could have been it. Connections account for a high percentage of no-starts. You'll know soon enough if it was that or not.....probably tomorrow morning?? Good Luck!

90% connections, but everyone keeps throwing parts on their Heeps! And the scariest thing is that the parts they put on are probably not as good as the one's that were put on in the factory. The used car I don't want to buy is the one "with many new parts".

:soapbox:

yeah, when my ballast resistor went south and I put a new fuel pump in thinking that was it I ended up dropping the tank again and reinstalling the OEM bosch pump since I knew it was still good and a better part than the airtex brand one I put in - and fit correctly without using these dumb little rubber shims and such

I know I sound like a broken record when I include "check/verify/freshen connections" in a lot of my posts but it's for good reason. MANY new parts are installed and the owner thinks that the new component fixed the problem when in reality, it was simply the freshening/disassembly/reassembly of the connections that was the root cause. And it will continue not to be realized because most suspect failed automotive parts aren't bench tested after the fact.

88klaws knew his way around a meter and kept connections in mind while troubleshooting and hopefully will be rewarded for it in that his problem does not return. And especially because he kept his sense of humor when working on a vehicle when it is so fawking cold out! ( I know how he feels, his weather is moving down to MN where I live as we speak......Yowsa!)

First, test your battery. In the temps you are getting a damn good battery is essential. A quick and dirty test of the starting circuit is to turn on the headlights and have someone crank the motor while you watch the lights. A little dimming is expected, but I have seen some vehicles where the headlights go off completely when cranking the starter--bad connections or bad battery most likely culprit.

Second, put an electric oil-filled space heater under the engine compartment, then put cardboard braced around the body to prevent airflow under the vehicle. Let it sit overnight and see if that helps.

Third, before trying to test the compression you need to have a good condition fully charged battery, and a good starter. If you don't, your compression readings may/will be inaccurate.

And last, electronic ignitions HATE low voltage situations, the truly do!