A short description of ignition coil pack used on Felicia:

 

Ignition coil pack (codes 5WP4260, 047905104)

Contains two power drivers for two double ignition coils; their HV contacts go directly to spark plugs. Two 6 mm Allen screws fit it to a sheet metal console. Sparking takes place simultaneously on two spark plugs: one ignites the mixture in the cylinder at TDC after compression, and the other sparks in the empty cylinder at TDC after exhaust.

A good ignition coil pack has a resistance value of around 8.7 kΩ between pins 2-4, respectively pins 3-4. A different resistance could indicate a faulty circuit. After removing the lid marked Champion and the hardened silicone under it, you get access to three contacts for the primary coils. The middle contact is common for both coils (+12V after ignition key) and it is connected directly to pin 1 of the 4-pin connector. Each primary coil has a resistance of 0.9 - 1 Ω. The ignition is suitable without modification for high RPM.

After desoldering those 3 contacts and drilling two outer rivets, the coils' cover can be separated and access to PCB can be obtained by removing the silicone inside. The most usual problem on PCB is random cold joints. The coils are driven in current by two power integrated circuits (VB921ZV - package TO220) switched by ECU. Each integrated circuit controls one coil. The pulse on pin 2 switches the coil for cylinders 1 and 4, and the pulse on pin 3 switches the coil for cylinders 2 and 3.

4-pin connector
Pin 1 - key switched power supply through fuse 20 (15A)
Pin 2 - pulse from ECU pin 71
Pin 3 - pulse from ECU pin 78
Pin 4 - GND from earth point E7 on the left wheel arch near the shock absorber.

evening all,sorry for the slow reply,work and family taking up my time recently....bit of time to myself tonight so ive done some more tests...first with the multi meter on 20k,no readings so went back to 2k.....

 

 

pins                  resistance                                  pins              resistance

                       

                        20k         2k                                                     20k        2k

 

1R - 2B               I             I                                 1B - 2R            I          1.329

1R - 3B               I             I                                 1B - 3R            I          1.350

1R - 4B               I             I                                 1B - 4R            I          0.551

2R - 3B               I         1.526                             2B - 3R            I          1.569

2R - 4B               I         1.866                             2B - 4R            I          0.653

3R - 4B               I         1.928                             3B - 4R            I          0.642    

 

ricardo.....thanks for the well written coil pack description....most helpful                                              

Edited 11 April, 201610 yr by morrispaul

Based on your measurements, the 'transistor' connected to pin 2 (responsible for firing cylinders 1-4) has failed. The maximum voltage of pulses on pin 2 is 8V. When pin 1 and 2 of ignition coil got shorted from bad insulation of cable coming from ECU, a DC voltage of 13-14 V was aplied instead, killing the 'transistor'.

 

The same thing happened to new ignition coil. So you have to recover the good 'transistor from old ignition coil (see photo) and use it to repair the new ignition coil. When opening the new ignition coil, watch carefully how the thermo-conductive grease is applied. Recover the grease, discard hardened silicone (you will use silicone for bathroom instead). If you work carefully, you will enjoy the ignition coil for many years.

 

 

Note: I asked my Czech friend Lugosy about restoring the silicone. He told me that filling the housing with silicone, he let it cure for a day. The ignition coil he repaired lasted 238,000 km when he had to send the car to a scrapyard due to badly corroded body.

This is one photo he took during repair, annotated by me,

 

Thanks for your reply ricardo......time to open up the newer coil then, I was a bit heavy handed with the old one, but what ive learnt on the first one I will use on the newer coil....managed to get a small tube of thermo conductive grease.£2 inc postage just need some silicone which I can easily get local......thanks for you help ricardo,busy now untill the weekend, should be able to spare some time to swap transistors and resemble and re-test........

Could you please take pictures of all disassembly steps? That would avoid any mistakes and could help other members with same problem. Until now nobody bothered to show how things look like after drilling out the rivets.

Yes, good idea, thats what makes a great forum, ive had a lot of help from various members on here so hopefully by posting a few pictures I can help someone else.