jenloe

I keep losing the #2 cylinder ignition coil. Any ideas what might be causing the issue?

Thanks.

UrS4boy

Are these the big coils attached to the 20v Turbo aluminum cover? How are you replacing them? How do you know that it is not the power output stage (POS)?

Here is some coil and POS info that might help (Click HERE)

jenloe

Thanks for all the info - it's been really helpful.

Here's where I am in diagnosis:

1) switched POSs - same cylinder missing (so, not a POS)
2) switched connectors between coils and spark plus - same cylinder missing (so, not a connector)
3) used BG44k in the fuel system, seemed to help (maybe?) for maybe a few miles after a bit
4) used 2 cans of techron (so, could be fuel, but certainly not obvious)

Result - back to old hesitation, constant.

I'm pulling the fuel rail out, and am running into a lack of knowledge - got any more fabulous threads (I'm doing a search now)?

UrS4boy

Might be an injector but you haven't ruled out a dead coil on that cylinder.
Here is some Fuel Injector Info and some Fuel injector wiring info

The injectors are attached to the fuel rail by clips and the intake manifold by O-rings sitting in inserts (PN 034133555 dealer only). You can remove the entire fuel rail with the injectors attached by removing the hold down bolts and gently prying the rail and injectors with a piece of stiff wood (= no sparks) levered against the cam cover. Clean the grit away from the injectors at the inserts first. Go slowly and be careful. Have some rags available to soak up any fuel (e.g. from a leaking injector)

jenloe

Thanks, it was easier than I thought. Dead cylinder didn't change after I switched the injectors. I ordered and just got a new coil. Any helpful hints on changing that? Seems pretty simple, but everything I do on this thing is a first time.

jenloe

Also, the reason I went through all this in the first place was that the coil has 'failed' on number 2 cylinder twice, with the last one occuring after only 8k miles. What could cause that?

UrS4boy

If the one with only 8K on it was new, that is *very* strange. The OE coils *typically* last upwards of 100K miles before starting to fail. Could be a wiring or ground issue. Certainly not normal.

jenloe

Changed out the coil, but probably just to make sure: the wiring looked shot to me, was hidden by electrical tape and protective hose. My plan will be to eventually replace all of the coil wiring and complete as original. Any idea on where I might be able to get the factory connectors (with unused pins) in order to rebuild as from factory, with wiring from the coils directly connected into POS's and power (without butt connectors)?

So - I now understand the POS's, fuel injectors and common rail, and coils. Not a bad project to get me started:-)

In any case, thanks a bunch. I've printed out a lot of the articles you sent me and stuck them in my manuals (still missing volume 2, but have volumes 1 and 3).

JEnloe

scarman

You have been asked since your original post "How are you replacing them?". Unless you provide some information when asked, it is difficult to help. The wiring needs close inspection since it is not unusual to see bare wires and shorts between wires and to ground.

I like your plan for new connectors. Others will consider it overkill. You can get connectors from efiexpress.com or eagleday.com. You can call if you can't decide exactly which connectors you need. They are made by AMP and new housings are available as well. A simple double crimp tool to install the new pins is available from Home Depot or similar supplier. All you need is a cheap crimping tool for bare connectors.


http://www.efiexpress.com/catalog/in...102379821fed5d


http://www.eagleday.com/

UrS4boy

The factory three pin connectors for the coil 12V power have PNs 443906233 and 443906247.