Quick help needed : 2.0, 2.2, coil

[Alan.UK]

Hi,

Can any one tell me if the bosch coil is the same for 2.0ltr and 2.2 ltr and also is it the same coil whether its for an S, E or T.

Basically I have a 71T which I think may have a faulty coil and want to know off what other engine can I borrow a coil to test.

Thanks

Alan.UK

[jstobo]

You can test your coil with an ohmmeter. Haynes manual has the values.

[Early_S_Man]

Alan,

If your car still has the factory Bosch CDI ignition ... it should have the Bosch 0.221.121.001 coil which was used on all CDI systems from '69 - '89. There was also an alternative 0.221.121.006 coil used briefly, but it had the same electrical specs and is fully interchangeable. Both coils should measure 0.4 - 0.6 Ohms on the primary and 650 - 790 Ohms on the secondary. Some inexpensive digital multimeterd don't measure below 1.0 Ohm with any certainty or accuracy, but the primary reading seldom varies, anyway! What you are normally looking for is shorts in the secondary winding due to 'flashover' and that will result in a lower than normal reading, if the short is stable.

Coils do not fail nearly as often as many people think ...

Much more likely is a 'connection' problem that can be remedied by disassembling and cleaning each connection in the ignition system. Remove the CDI unit from the electrical panel and clean all of the ground strap connections, too! Remove the ground tab connector 'D' just above the 3-pin connector and clean both tab and box surface where the tab connects with a fine wire brush. Reattach with silicone grease on screw, washer, and tab.

Clean all of the quick-disconnect 'Faston' connectors [and ring-terminal connectors at the coil] with Q-tips and 9% pickling vinegar, followed by distilled water rinse and dry. Retension the sides of the Faston connectors ever so slightly with needle-nose pliers so that the gap is closed slightly for better tension and gripping force on the tabs. The use of silicone grease on all of the connections can help prevent future problems with corrosion on the connectors!

You might be interested in reading the Bosch Testing documentation I posted in the following thread. If your browser stalls before all of the pics are loaded ... just hit refresh or reload.

Perma-tune CD or Bosch CD?