1G Turbo Ignition Coil Test Results help

[JohnnyC]

Sorry if this has been answered, but I couldn't find an exact answer I'm looking for unless I'm using the wrong search terms.

So, after a couple months of my car missing under acceleration, it started firing only two cylinders a few days ago. (No spark to cylinders 4 & 1)
Since the two cylinders that weren't firing belonged to the same ignition coil, I
started with the ignition coils as far as diagnosing the problem.

I've pulled the coil pack and tested resistances:

FSM Specs:
Primary Coil Resistance 0.77-0.95 ohms
Secondary Coil Resistance 10.3-13.9 K ohms

Actual Specs:
Coil for cylinders 4&1- Primary Resistance 1.1-1.3 ohms - Secondary Resistance - 11.9 K ohms (Questionable Primary Resistance)

Coil for cylinders 3&2 - Primary Resistance .9-1.0 ohms - Secondary Resistance - 13.12 K ohms (All resistances seem to be in spec)

My question is this: I realize that the primary resistances for the coil in question (cylinders 4&1) is technically out of spec, but is it close enough that you think it may not be a bad coil (since secondary resistance is in spec)? Only reason I ask is I can't afford to be throwing parts at it trying to fix the problem at this point, and my next step would be the power transistor which new runs nearly $200. So I don't want to replace this coil if it could still be the power transistor that is at fault, as I won't be able to return the coil if it wasn't the culprit. I'm thinking it is the coil since when my power transistor went bad before, it didn't miss under acceleration like it has been as of late, 2 cylinders just plain stopped firing in that instance.

Any insight here would be helpful.

Thanks!!!

 

[g4ebguy90]

Out of spec should make it miss under load, not all the time. But it does need to be replaced eventually.
If it is dead on 2 cyls, I'm going to go with the transistor.

 

[JohnnyC]

Out of spec should make it miss under load, not all the time. But it does need to be replaced eventually.
If it is dead on 2 cyls, I'm going to go with the transistor.

Not quite understanding you here... It WAS missing under load (acceleration) in the months leading up to cylinders 4 & 1 not firing at all...thought I made that apparent in my first post.

Also don't understand how out of spec wouldn't make 2 cylinders not fire (I think I'm interpreting your statement correctly here). If out of spec doesn't mean it's bad, then whats even the point of the test procedure/results??

So given all the info in my original post, your saying you think it's the power transistor based on what exactly? Based on the fact that 2 cylinders are dead? Because that's what I'm getting out of your post, but not understanding your logic behind it...

Has anyone tested a bad ignition coil? If so, was primary resistance higher or lower than specification? Or just in general does anyone know if a bad coil would have higher or lower resistance than spec, or could it go either way?

 

[JohnnyC]

Well, nevermind. I sucked it up and went ahead and replaced the ignition coil for cylinders 4&1. Runs fine now. Even though the primary resistance was only just a little higher than spec (+.2-.3ohms), and the secondary resistance was in spec, it was bad apparently. By the way I forgot how fun it was trying to wiggle that coil pack in/out.