no spark on cylinders 1 and 2

[jim milewski]

I pulled the ignitor out of my running Forester and put it in the Legacy because that one went bad, when I got the used replacement for the Legacy I put it in and then put the Forester ignitor back in the Forester, now it won't start, the timing light indicates spark on cylinders 3 and 4, but nothing on cylinders 1 and 2. The ignitor tests good and runs in the Legacy, the coils have been swapped and still no spark on 1 and 2. The coil has no opens and all voltage and continuity checks are good. One thing I did do was accidently left the key on with no ignitor hooked up, possibly this may have burnt out a driver transistor in the main ECU (you can see the component diagram/schematic in my other post "No spark Legacy". My best guess is the ECU is at fault, I took it out and am checking for a part number, any help appreciated.

[davebugs]

Opposing cylinders typeically means coil pack, plug, or wire problem.

 

And is much more common than a single cylinder problem you originally had.

 

Try swapping plug wires. 1 to 3, 2 to 4 and see if it stays with the cylinde ror plug wire. Then try plugs if it stayed with the cylinder.

[jim milewski]

Dave, my original problem though I did not know at first was both cylinders 1 and 2 were not firing, a new ignitor solved that. The coils test continuity good from the middle pin (voltage supply) to the two outside pins (primary windings), I tried new plug wires and hooked them up to new plugs and grounded the plugs without actually putting them in, I turned it over and get one spark across the electrodes then nothing. It's looking like the ECM/ECU. It's something I did, because the Forester was running fine before I removed the ignitor and put it back, here's another kicker, the Legacy ignitor which was only firing on 3 and 4 (original problem) is now firing on all four!

[davebugs]

I'm a simple "swap parts out" kinda guy since I have the parts and it's easy to do.

 

You need Cougar or someone. With the knowledge and patience for electrical detective work.

 

I've NEVER seen an ECU in a Subaru go bad - perhaps I'm just lucky. I don't even pull them when I scrap cars.

 

Good luck

[jim milewski]

Dave, just got in from the garage, basically did as you said, this time in a more patient and methodical way, I put battery voltage on the coil and made a "point" setup for coil and plug testing purposes and did get spark finally on plugs 1 and 2 (possibly with the hot spark I was making it may have cleaned a gap on a fouled plug), anyway I got spark, I took out the computer and put it back in reseating all the connections, so now to see if it starts, and it did!

[davebugs]

Perhaps you're done then.

 

If you end up doing plugs ask here.

 

Don't go exotic.

 

I forget what you're working on. But if it's DOHC use the NGK plugs with green writing that are 2 bucks each.

[jim milewski]

I'm with you on the NGK, very nice spark, used them back in the sixties on my Triumph motorcycle, but my son thinks the more you spend the better, he went and ordered Denso Iridium plugs behind my back, his dime, he is not a mechanic and falls for every pitch out there. My experience is the small electrode area on the Iridiums make them prone to foul easier, the spark is no hotter, possibly they may last over 100 k miles, I don't know and have never had a reason to use anything but an NGK standard plug, one thing I do know about NGK is the lower number is hotter, opposite from Champion where the higher number is the hotter plug. I appreciate your help, I'm a Subaru driver now for life, once you get familiar with these things you're hooked, such a neat car, love em both, I wanna do a 2.2, there was one for sale up the road, don't need it but I want it, $500 was the asking price, needs HG job, these things are addicting!

[davebugs]

A 2.2 HG problem is also pretty rare.

 

Glad you solved the miss.

[Cougar]

Glad to hear things are working ok now on both cars. It sounds like we have another Soob convert here.

[jim milewski]

Cougar, ya, all this work, HG job, front axles, calipers and more has worked to "bond" me to these rigs, I love driving them, maybe the opposed four has some sort of "feel" that agrees with me, here in VT there are quite a few and they come up for sale, some pretty affordable, I think these are just the neatest cars, luv em! This forum made a big difference and all you guys helping was a real blessing!

[GeneralDisorder]

The Denso iridium plugs are good - I use them on all the DOHC engines (especially the turbo's) - not because they work any better but because they will last 100k and the fishing expedition required to change plugs on those engines is to be avoided if possible. I use the cheap NGK's on all the SOHC engines. I've never had fouling issues from either.

 

So he made and acceptable choice - the Denso's are about half the price of the NGK iridium version. Japanese made and good quality in my experience.

 

GD

[Cougar]

The "feel" of the car is something that I think a lot of folks like. I saw a neat little demonstration model once some time ago at our dealship here. Small models that showed the difference in the front to back balance between a Soob and other 4WD vehicles. It also demostrated the lower center of gravity of the Soob. Enjoy the ride and glad we could help you out.