Tote

This morning I replaced the old oil filled coil coil on my clevo with a new Bosch epoxy coil. All works fine except that my tacho is now erratic and the needle bounces all over the place. My ignition is the XC factory electronic type and the new coil is the correct one for the ignition module. There is no radio supression cap fitted as I dont need it.I havent tried swapping the old coil back in yet but I was wondering if anyone has experienced anything similar?
BTW the tacho is a pretty cheap and nasty one, however I would not have thought this would have made much difference.
Regards,
Tote

smciner1

I have had a similar problen with my XB. The aftermarket Ignition system made the Tacho read slow. Insome cases a Tach Adaptor may need to be fitted. It is an Ignition related problem in my case. I can't say I have heard of that problem by simply changing a coil.

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xr6wgn

Just two things come to mind
Is the coil you put in compatable with the electronic ignition??
I know that when I replaced the coil on my XD I had to run the resistor type (ie Bosch GT40R)

If it does suit the ignition, have you put the tacho pickup lead on the wrong side of the coil??

Sorry if it sounds so obvious but it's all I can think of.

Paul B
XR6WGN

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Tote

Took the ute for a run this afternoon and the tacho seems only to be erratic below about 1500RPM. I can live with it but it would be interesting to know why it happens. Maybe crossfire from one of the plug leads??? Checked the connections again and the tacho is connected to the negative side of the coil and the other connections are OK. Plug leads are all new silicone ones.
The coil is the one that is suggested in the Bosch book so it should be OK. The spark is heaps stronger than it was previously so it may be that I have been running the wrong coil previously anyway.
Thanks for the replies
Regds,
Tote

9psi EB

Tote,

You may need to put a resistor inline with the tacho wire.
Simply try a 120 ohm resistor from dick smiths etc, and see what the result is.

I know all the new falcons run inline resistors, from EB onwards, and they all use epoxy coils.

I think its due to the different discharge / feedback properties of the E core coil which can trigger the tacho more than once per spark.

Regards
9psi EB

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brenx

I am guessing your running the MEC 717? or the MEC 716? I agree you get a stronger spark on the clevo. Which is all good. I've been speaking to various people about these coils being mounted on to the head of the cleveland (factory mounting).

The longest ones lasted is 2 1/2 years :(

I had a MEC 717 fail after 17 months. I posted on Ford Forums about it.

I shot down the wreckers and picked up another MEC 717 off an XF (yes XF run the same coil). Also picked up an old oil filled coil for safe measure. $22 for both coils and no I won't get stranded again.

I didn't want to invest the $60 to have a coil fail again in 17 months.

In regards to the tacho issues? I am guessing your using the factory dash tacho? I run a speco aftermarket tacho and ignition US Motorcraft dizzy setup.

Check it tonight in the dark and look for misfires? Maybe even the dizzy cap is work out and misfiring?

Sounds really odd.

Brenden