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???
Any suggestions welcome!!!
very simple take a line connected to the fuel rail and place the other end
in a clear large container then run the vehicle if u get bubbles after a
few minutes the pump is shot. still laughing buthead
Dan C wrote:
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
A temperature sensitive connection (inside or outside) of the coil could
cause this. There could be a problem with the Accel coils internal
connections or one of it's external connections could have been corroded or
loose. If it was an external connection, your swapping it with the
origional would have cleaned that up and if it is internal, the coil is
defective. When you increase RPM's of the engine, you increase the current
flow which will heat up an improper or corroded connection and cause it to
lose some or all of its ability to conduct and the coil output voltage will
drop considerably if not fail completely and will stay this way until they
cool down again.
If at first you don't succeed, you're not cut out for skydiving
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