Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: jandh on January 07, 2015, 09:01:40 PM

Title: FIXED - Jeep won't start, Fire and fuel are good.
Post by: jandh on January 07, 2015, 09:01:40 PM
Anyone have any idea's to try? I'm at a loss here.
Jeep started running a little rough, like it was missing and also started to smell rich. this got progressively worse over driving it 4 or 5 times over a 4 month period.
Last night it was running rich and backfiring ever time i reved it up while driving. finally while idling in my driveway it stalled and will not start at all.
-It has good gas and is getting fuel not only on the rail pressure but we even pulled the injectors and watched them spraying in order.
-it has good spark and new plugs
-Replaced the coil
-Cap and rotor are new and cleaned, along with plug wires.
-turns over just fine
-throttle body clean
-Battery good and charged
-air filter removed and still with tons of air, gas and fire. no starting.
-Vacuum lines checked
-Throttle sensor has a good strong 5V going to it, so no short.
-Compression is 1-120, 2-100, 3-120, 4-100, 5-120, 6-110
Will occasionally backfire lightly through the throttle body, but not often.
Is constantly flooding because it won't start.
I feel almost defeated here. Gas, air and fire make combustion, so what the F#^% am I missing??

Mileage is 192xxx KMS

May only guesses left are:
Timing chain - but if it's broke wouldn't the rotor not turn?
Map sensor
CPU
drive gear on distributior
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: pooljunky on January 07, 2015, 09:44:34 PM
TPS sensor or I think I want to say crank sensor..  the one that bolts to the bellhousing
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: jandh on January 07, 2015, 09:48:33 PM
It's reading 5v from the plug and 5v once plugged in, usually when a sensor fails it shorts the contacts when powered.  However weirder things have happened since I've seen coil that fire still not be good.

I'm going to try to find a replacement just to ease my mind.

When the bell housing Crank sensor is done, doesn't that eliminate fire completely?
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: cLAY on January 07, 2015, 09:57:10 PM
CPS. Replace it. Weird things happen when they start to fail. Also have had similar symptoms from a bad coil. But I would do the CPS first.
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: jandh on January 07, 2015, 11:17:49 PM
CPS has that much control eh? well that will be the next sensor I will deal with.

The coil was replaced tonight, not a difference at all.
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: pooljunky on January 08, 2015, 12:45:28 AM
I have a few of those somewhere.... where? good question lol
Title: Re:
Post by: BUKI on January 08, 2015, 08:56:07 AM
I'd think timing??
But it'd probably backfire turning over.
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: jandh on January 08, 2015, 06:14:01 PM
Thanks all, checked the timing today, dead on.   

Problem was 6 completely fouled plugs...   Must have been bad gas to foul 6 new plugs within an hour of run time. Changed out all 6 and bam fired right up. Even though the original plugs had spark, it must have been to weak.

Thank you all for your help
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: JackstandJohnny on January 08, 2015, 07:31:51 PM
did you use the Champion copper plugs?

thats weird to could 6 plugs that fast and together. 
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: ornamental on January 08, 2015, 08:03:23 PM
Thanks all, checked the timing today, dead on.   

Problem was 6 completely fouled plugs...   Must have been bad gas to foul 6 new plugs within an hour of run time. Changed out all 6 and bam fired right up. Even though the original plugs had spark, it must have been to weak.

Thank you all for your help
I had a similar issue,  the plugs were wet from being flooded.....  Needed cps and coil also.
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: Immortal on January 08, 2015, 08:54:31 PM
Jeep started running a little rough, like it was missing and also started to smell rich.
I had a similar issue,  the plugs were wet from being flooded.....  Needed cps and coil also.


I think that may be your problem.....
Title: Re: Jeep won't start, Fire and fuel are good.
Post by: jandh on January 09, 2015, 08:42:18 AM
did you use the Champion copper plugs?

thats weird to could 6 plugs that fast and together. 

Yes the Champion copper plugs were the ones that went bad. Ive never used another plug in my life.

Until yesterday that is.