Coil Pack Resistance When Failing

[Richie-Van-GTi 74 2 Cars]

Would a coil pack increase or decrease in resistance when it starts failing? My santa fe has a suspected failing coil pack (uses 2 wasted spark coils). Theres very little difference in resistance's but regardless of tempos there is a difference all the time. Would the higher or lower resistance be most likely to be at fault?

[DamirGTI 344]

Does the engine misfire ? or something like that ...

 

Damir

[Richie-Van-GTi 74 2 Cars]

When its up to temp (just before fans kick in) it starts to have the occasional misfire at idle and often a severe faltspot / hesitation at around 2k, often coupled with misfiring. Above this it clears and goes ok, but until it gets nice and cool again it persists. I have been told by another mechanic he changed a coil on one for the same reason and it cured the fault. I've personally fixed a rover with almost the exact same issues by a coil pack change, also on the same sort of coil set up.

[DamirGTI 344]

Try this then :

 

Unplug the lead from the coil pack (one by one) and stuff/slide an piece of rubber vacuum hose (say 2cm long ..) on the lead end , then put the lead back in the coil pack terminal - so with the piece of vacuum hose down in between the coil pack and lead .

Then , you'll need some kind of insulated probe to do this , but an thicker gauge wire will do as well - connect one end of the probe/wire on the chassis ground , start the engine and poke with another end of probe/wire on the middle of the vacuum hose -> it'll start arcing from the hose onto the probe/wire when you poke the hose ... try/test all the 4 leads/coil pack terminals separately like this and if you spot a difference in arcing intensity from one to another terminal , then you have a bad coil pack ... doubt that all 4 coil pack terminals are fubared , but if so , can try testing an known good used coil pack like this just to see how arcing pattern must be on a good coil pack ..

 

Damir

Edited October 29, 2010 by DamirGTI