My 99 xj, 4.0 with AW4 decided not to start this morning. Absolutely wicked cold (see pic). At one point I got a no bus message but a smack on the dash took car of that. It cranks and wants to start but no joy. CPS is only several months old (Mopar one), new coil..... I disconnected and reconnected the CPS,no joy. Gauges work fine. Could this be a water/ice in the fuel issue?

Edit* I scanned it and there are no codes........

 

For a crank - no start, I would start with checking for fuel delivery/fuel pressure and if you're getting spark and how strong the spark is. Know what's missing in your starting equation is the going to lead you down the right path in diagnosing it.

 

Hey..As I guess you know 99 is almost none of my business. I like your thinking...any water might be a problem. Do you hear the pump run for a second when you turn on the ign? Do you get a squirt out of the schrader valve on the rail, into the rag you are holding there when you depress the dealie?

If nothing squirts out, a gauge won't help. If it fires some with a little starting fluid, may well be fuel and not spark is the issue.

I believe your mini-fuses might be important. The one for the ASD relay can blow from something like a shorting 02 wire, then shut sown other stuff, like fuel and spark.

 

Update- replaced the dist. cap and rotor with good condition ones. They needed replacing. A little better but still no joy. Fuel pump is running when the key is on and fuel at the rail. It really wants to start but won't. It's soooo cold that it's difficult to work outside......One thing I did notice is that the volt meter isn't moving when I engage the starter. When the key is on, it comes up......

 

Unfortunately we all have water (and corn) in our fuel.
Whats the fuel pressure in psi?

 

Agreed.

Know that being at -31 farenheit, you are at the spec. edge of starting for many vehicles.

Pull a plug. Keep it attached to the plug wire, place the plug electrode near a good engine ground. Have a buddy crank the engine while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white spark is a weak spark which may not be strong enough to start the engine. A weak spark is often associated with a weak ignition coil.

If you have good spark (and only if), then try introducing a shot of starting fluid or gas into the intake to see if it fires. If it fires with this strategy, you have identified a "fuel delivery" problem.

Good luck. Sure hope it warms up for you!

 

I don't have a fuel pressure gauge so I don't know what the psi is. I'm pretty well dead in the water as I'm doing this alone and far from town.

 

I take it no form of block or coolant heater?
If worse comes to worse put a hair dryer under the hood for a while then give it a shot.

 

Just a guess but I agree with tj -31 , might just be too cold , engine is possibly flooded. plug in the block heater... battery blankets help as well . If you pull a plug to check spark, see if they are wet with fuel.

 

If I was alone, in a desperate and cold situation, I might suck an 1/2 oz or so of fuel into a tube or line of some sort, (by mouth), then with the tube off the air cleaner blast it in there, towards the engine, quick put the tube back on the air cleaner and try it.

If the air cleaner is not secure to to inlet, a predictable backfire will light the fuel. With it on, it can't burn long without air.

It's often handy to have a wet towel handy. Not sure how long a wet towel is handy at -30!

 

Would low battery voltage cause a no start even though it could spin the starter. I read that XJs don't like a low voltage condition....maybe it's my battery?

 

99 is not my business. 87-90 will not start unless it reaches 300 RPM. The chemical reaction in a battery that makes current IS very temp sensitive. Battery warmers/heaters I guess are not rare in cold climets.

I suppose a guy might bring his battery in, to warm to "room temp". It will take a long time to warm through though...

Someone here should know better than me. A jump from something warm and running might be nice.

 

low battery voltage will definitely produce hard-start and no-start conditions

also your IAC may be frozen

 

Did you change the sensor in the distributor? Its called a Camshaft Position Sensor. I had fuel still going but no spark. I had to get a whole distributor assembly and it included the sensor. About $100 at autozone with lifetime warranty. They dont sell just the sensor. I think O Riellys had the sensor but it was like $40, for the extra $60 Id rather get the whole system.

 

At this point, it looks like a failed fuel pump. Turn key to ON, pump runs several seconds to pressurize, but very little fuel comes out the schrader valve on the fuel rail.... Plugs should be soaked with all the attempted starts, but barely wet.....