5thgenmaxima

iTrader: (1)

So here's the deal..
I had the p1320 code. Primary ignition system.
Only twice have I had a mis..It was pretty bad when it did mis though.
We all know that's 99% change it's coils right?

So I put a fluke 98 Scope on the front 3 coils to check them. (unfortunately the mis had gone away by this time.)

What I find is at idle all 3 wave forms are perfect.
Under throttle snaps I shows bad consistently, one shows good, and one shows bad 1/3 or 1/4 the time..
So my problem could be one of the two fronts going bad or it could be a rear one. Since 2 out of 3 of the front ones are going bad anyways I decided to order all six.

I've set some time aside on Monday where I'll hopefully be able to scope the 3 front ones and POSSIBLY the 3 rear ones, bring my camera along and check resistances so I can help bigfat with his wonderfull how-to thread.

Obviously the coils are going bad under load and the 02's are picking this up and making for a lean condition.
(I don't want to go into depth as to why I say this, Basically the fouled spark = unburnt fuel in combustion chamber = ECM leaning out the mixture.)

Right now my LTFT (Long term fuel trim) is -10%.

When the coils are fixed this will in turn give it a cleaner spark allowing for my LTFT to go back to normal.

Following along so far?
Ok now my question is which theory do you think is correct?
1.) The re-enriching of the fuel mixture will burn more fuel, but your car will run better.
Or
Since the spark is again good and since there will be no unburnt fuel under a load, your engine will run at an optimal level and you will get better gas mileage.