H.T. Terminal point on aftermarket Marelli Coils

Hi All

After suffering a failure on Bank A I’ve set about a full update of the coils, ignition leads, application of the “cut & squirt” preventative solution on the distributor as per The Book. All going well until I approached re-assembly of the new components.

The car had the original Magnetti Marelli stamped coils (PN DAC4608 - Stamped BAE504), the H.T. terminal on which have a receptacle with a receiving “dish” (female) to accommodate a contact to the external surface of the formed head of the H.T. lead connector. This “dish” on the coil is exactly the same design on the terminals on the distributor.

The aftermarket coil has a different arrangement. On the aftermarket coil the H.T. terminal has a central pillar with no internal “dish” as such it appears the pillar is to insert into an internal detail on the H.T. lead connector. This doesn’t match with either the leads that were on the car nor the replacement after market leads (that look and measure exactly as per the leads on the car originally and built to OEM specification).

The part number for the aftermarket coil is IC443 and is a design meant to be built to OEM specification. After calling around a few stores specialising in Jag OEM parts and talking with some knowledgeable folk it appears that the OEM part with this “pillar” is distributed broadly.

I’m a little concerned about using the replacement coils as it appears that for the transmission of the spark to be successful it will need to arc between the pillar on the coil and the receiving side of the HT Lead.

So a couple of questions, is this the correct part? Has anyone else encountered this? If they have is the terminal compatible with the H.T. Leads?

Ted

Sydney - 1989 XJS convertible - 5.3lt Marelli ignition

No direct experience but it sounds to me like you simply have the wrong coil

Cheers
DD

Hi Doug

Thanks for the note, exactly what I thought, yet my review of suppliers here in AU has found the coil made to OEM specification for P/N DAC4608 has a pillar not the dish. Is anyone able to confirm their aftermarket coil?

Cheers
Ted

I’ve done some further research and found the issue has been found previously and noted on the jaguarforums pages here:

https://www.jaguarforums.com/forum/xjs-x27-32/ignition-coil-warning-135443/

Seems thus is a real issue in after market coils! I think installing the coil without a goid connectiin at the H.T. Terminal could result in some very odd failure mode/inconsistent running…

Anyone able to confirm their terminal plug on aftermarket coil?

I have aftermarket coils, but I am in the US and our suppliers are different.
STANDARD MOTOR PRODUCTS UF136 is what I have, exact fit:

Hi Steve

Thanks for the comment. Yes after a litle more research I’ve found the part number UF136 or C-1202 all seem to have the correct H. T. terminal. Unfortunately I’ve not been able to find any suppliers in Australia for this part number! The aftermarket part IC443 (pillar terminal) along with UF136 & C1203 (dish) are all sold as a direct replacement for DAC 4608 even though the terminal is different…

Well, you don’t want to mess around with a Marelli setup… need to figure out the “right” solution. I’ve never seen a post like that, but at the bottom of this page they talk about a ford coil pack and a pin type connector… FWIW… looks like it could fit…
http://www.magnecor.co.uk/helpful_terms.asp

Hey Bob

Thanks for the link, yes with the propensity to melt a cat I’m not willing to mess with the setup, the search continues!

Cheers
Ted

Can’t get the original part (DAC4608) from Jag for love or money here at the moment.

After further research of aftermarket coils I’ve found NGK make one to OEM specifications under their part number U1047. I’ve order 2 and should have these on Monday. I’ll report back.

The listing on the NGK website shows the correct H.T. terminal, so fingers crossed:
https://www.ngk.com/product.aspx?zpid=47172

I’ve just collected the NGK coils and can confirm the HT lead terminal is correct!

Of great concern is the fact that ALL after market coils currently being distributed in Australia under DAC4608 have a pin style connector not compatible with the OEM coil to distributor leads.
The shops I’ve contacted to check parts are very well established and reliable sources of parts over here. Would be interesting to find out how broadly these incorrect parts are being distributed.

Nothing prevents the connector engaging and I imagine if installed the result would be some serious arcing internal of the connector and some odd ignition failure mode at high revs.

The Marelli system is already at a handicap without this thrown into the mix. I would hate for any cats to become a statistic due to this part

I note that the NGK coil also has BAE504 hot stamped on the casing FWIW and branding to show it was made by Champion?

Now time to get these under the hood and get the old girl purring again!

IMG_20191104_133631_02|375x500

BAE504 stamped on coil

I can’t comment on this specific case, but I have certainly found instances where the cross reference of a particular part is wrong in the catalogues. Once the error creeps in it seems to become pervasive, so wherever you go to order handbrake shoes for an XK8 you invariably get front pads that fit some random Citroen.