I recently had the headgaskets, timing belt, water pump and t-stat replaced on my 97 Legacy Outback. When I got the car back, I drove it about a week and it lost power. I gave it back to the mechanic who diagnosed the problem as a bad coil, lost spark to cylinders 1 & 2. I replaced the coil and the ignitor (for good measure) along with new plugs and wires and continued to drive the car. Less than a week later, the car started running poorly. I returned it to the mechanic again and he diagnosed the problem as another bad coil, having lost cylinders 3 & 4.
With a coil priced at $125 from the dealer, I don't want to continue buying new ones without having an idea of what might be causing the failure. I'm wondering whether there is a grounding strap affixed to the intake manifold (where the coil derives it's electrical ground.)
If anyone can describe the location of the grounding wire for the intake manifold, I'd take a look for it, clean the connection, etc.
One other thing, all the aftermarket coils I've looked into seem to be considerably different than the OEM part. The towers on the aftermarket units have a male electrode and tower diameters about half the diameter of the Diamond F-569 OEM coil. Also, the original part has a pigtail with a connector while the aftermarket coil seems to have a molded connector that doesn't fit the car's wiring harness. Lastly, the aftermarket coil (Duralast #C1150) doesn't even have a bolt pattern that hits the 4 mounting posts on the intake manifold.
I'm stumped. I hope that some of you guys have some info I can use to get the car back into service.
just to get this into the archives, my problem ended up being an original failed ignitor (ignition module) located on the firewall which i replaced with a junk yard unit which turned out to be bad as well. the first one failed on the cylinder 1 & 2 circuit, the second one had failed on the number 3 & 4 circuit.
$196 later for a new ignitor and it was fixed.
the confusion over the replacement coil turned out to be that even though my car was built in 97, it was titled as a 98. the proper replacement coil was listed as a 96 part. either the engine had been replaced as a unit from a 96 model or there is some crossover with a model year change on the coil.