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Old July 24th 05, 01:55 PM
Peter
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> 99 Durango 5.9L has started behaving really weird. It starts up more or
> less fine (have to crank it more than usual), and will idle fine. When I
> floor it under load RPMs won't go over 2-3K, it starts coughing, and idles
> very roughly, then stalls (but sometimes will recover to smooth idle). I
> hooked up ODB scantool, and all sensors seem to be in working order.
> Whenever it starts stalling oxy sensor shows lean mix, and ignition
> advance fluctuates wildly between 10-25 degrees. No error codes. I even
> reset PCM by disconnecting battery - no joy.
>
> I'm thinking ignition trouble... had all wires, distributor cap and coil
> replaced recently with Accel hi-perf components... could it have something
> to do with this???


You guys were all wrong

It was the coil

No air bubbles in fuel as far as I can tell ) Fuel pump is fine, too.

Swapped back OEM coil, and it runs as new. I also measured primary
resistance on both coils, about 22Ohms on both... dunno how can I measure
secondary winding. My idle is just a tad rough now - which was the reason
why I 'upgraded' to Accel in the first place.

Now, I wonder how on earth can faulty coil account for smooth idle at first,
then spluttering/missing during acceleration, and finally settle down to
very rough idle? My only guess would be cross-induction caused by higher
voltage... there actually is TSB out for 99 Durango covering ignition wires
cross-induction. When I swapped back the original coil voltage went down and
cross-induction stoppped. If so, why did it run just fine with Accel for
several months???

Peter




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