Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: mattiemjbb on July 22, 2007, 05:51:08 PM

Title: zj not starting help needed
Post by: mattiemjbb on July 22, 2007, 05:51:08 PM
So I got a new problem… my zj wont start, it turns over but that’s all, it won’t actually fire for some reason.

I seem to remember that when the ignition gets to the second position when all the lights come on at the bottom, the needles for the fuel and battery also go to their respective places, but there not, they just stay at the bottom.  The car still has fuel in I used it around 1.5 hours ago and it worked fine, and had around 1/3 a tank.

Since then I have eaten a kfc and put on a new rear exhaust pipe but not touched any thing else, except perhaps the rear o2 sensor which needs replacing, but this shouldn’t affect the starting should it? Shouldn’t it just revert to stored values as I think it already was.

I have a feeling it may be an electrical problem but I can only find one fuse box the one in the engine bay, I have a feeling there should be a second but im ashamed to say I cant find it

Please help!
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Post by: Mike Pavelin on July 22, 2007, 08:30:44 PM
Try disconnecting the battery for a minute, then try again.
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Post by: mattiemjbb on July 23, 2007, 08:29:31 AM
tried it if an o2 sensor was totally broken and disconnected could this cause the problem, or should the comp revert to saved values
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Post by: tartanzj on July 23, 2007, 01:37:32 PM
Fuse panel is located in driver footwell on ZJ , at accelerator pedal. Hopefully its just something in there!
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Post by: Mike Pavelin on July 23, 2007, 05:33:45 PM
The downstram 02 sensor only monitors cat performance. If disconnected it'll log a fault code and put the engine light on but the Jeep will still run ok. If the wiring to it is shorted, however, it could cause a problem.
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Post by: mattiemjbb on July 23, 2007, 09:07:56 PM
well theres a new one comming tomorrow, as i know its deffo borken, so ill see what happens when thats in, perhaps it is shorting. does anyone know if i can use a generic obd II scan tool to pull codes or do i need a special one?  

also another thing i noticed, when i normally start the car the fuel pump buzzes for a few seconds then stops, now it just keeps going, also all the indication guages are at 0 and the fuel low light is stuck on, its deffo not empty as i just put 20l of gas in.  and theres deffo power as the engine turns, just not fires,  the engine check light is not on.
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Post by: Mike Pavelin on July 23, 2007, 10:53:20 PM
See if you have a spark.
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Post by: mattiemjbb on July 25, 2007, 09:00:55 AM
checked that and there was no spark, so went on checking every possible sensor for a malfunction.....

turns out that the farther inlaw did not check all the fuses he was supposed to   :evil:  and it was one tiny little fuse that has caused all the trouble, replaced it and it worked,  

seems silly to have so many thigs controlled by one little fuse, seems to controll fuel pressure, dials, and ignition, it also stopped me being able to pull any codes.