Picked up a 92 Subaru Legacy 2.2 5MT with 250k miles for $159 .

Ran horribly but ran.

Did a complete tune up with.....

New plugs , wires , fuel filter , PCV , Air

No change

 

Checked for spark at coil and only 1 and 2 are arc ing from the coil to plug wires.

Nothing on 3 and 4 .

Swapped out coil for known good coil = no change - still no spark

Swapped out Ignitor for known good ignitor = no change - still no spark

 

Whats next ?

Car starts right up and runs , just only on 1 and 2 cylinder.

 

Thanx

First though would be to double check "known good" stuff by installing your "broken" parts on a good running car and seeing if the problem follows the parts.

 

Reason I say this is because that problem should be electrical (not mechanical or fuel delivery). Didn't ask what brand of wires because 2.2's are pretty forgiving.

 

Because you've swapped the electrical stuff (except ECU which very rarely go bad) and also have wiggled all the connectors during swapping as a way to double check those connectors.

parts came from working vehicles.

electricals have been wiggled and tripple wiggled = no spark at 2 & 4 still

The yellow wire at the coil is 12V power. The other two wires go directly to the igniter. Check continuity of both wires (end to end) to rule out a broken/cut wire.

Will do but if that wire did not have continuity then none of the plugs would get spark and Im getting spark at 1 & 3 plug.

Check the reluctor tabs on the crank cog wheel and see if some of the tabs have been broken off. They trigger the ignition system. Sometimes they get damaged and break off. It's not a common problem but it does happen.

 

Here is a link to a picture that shows some of the tabs.

http://i190.photobucket.com/albums/z314/987687/98%20Legacy%20GT/IMG_3519.jpg

Edited May 14, 201114 yr by Cougar

Check the reluctor tabs on the crank cog wheel and see if some of the tabs have been broken off. They trigger the ignition system. Sometimes they get damaged and break off. It's not a common problem but it does happen.

 

Here is a link to a picture that shows some of the tabs.

http://i190.photobucket.com/albums/z314/987687/98%20Legacy%20GT/IMG_3519.jpg

 

Will do.

I do plan to tear it down to the tbelt soon .

thx

In the picture you can see the set of three tabs. There are two sets of these tabs.

Will do but if that wire did not have continuity then none of the plugs would get spark and Im getting spark at 1 & 3 plug.

 

You said no spark on 2&4.

The first post says you do have spark on 1&2.

Then you say you do have spark on 1&3.

Plus 1&3 are on the right side of the engine 2&4 are on the left side (from inside the car).

We need to know exactly which plugs are not getting spark. Otherwise we're just chasing our tails.

You said no spark on 2&4.

The first post says you do have spark on 1&2.

Then you say you do have spark on 1&3.

Plus 1&3 are on the right side of the engine 2&4 are on the left side (from inside the car).

We need to know exactly which plugs are not getting spark. Otherwise we're just chasing our tails.

 

Yep. Changes it from electrical to timing, mechanical or fuel if problem stays on same head.

sorry .

Just to set it straight .

The front two are arcing but the back tow are not.

Which means I have 1 plug on each head firing .

Did I square that up?

Sorry for the confusion..... long week.

Try changing out the ingitor. Happened to me a couple of times.

Ignitor has been replaced as well as plugs , wires and coil.

Let me restate this.

 

If you took parts off the "problem" engine and placed those parts on a good engine - was everything fine?

 

In other words I'm questioning your "known good parts". Not as a personal thing, but as a diagnostic thing. And proving they work on another car confirms that they are o.k.

I can agree 100% with you on doing that type of swap but unfortunately that is not an option as I have no vehicle to swap with.

Ok then, So the rear half of your coil pack is not making spark. This is where those 2 wires come into play. Those wires are grounded by the igniter module, one at a time, so that the coil can build the magnetic field which creates the spark.

Those wires go from the coil pack to the igniter module on the firewall, but they go through a couple of connectors along the way. If one of them does not make a good connection, is dirty/corroded or the wire is cut or even chewed by a mouse, the igniter can't ground the half of the coil that that wire goes to, it can't build the magnetic field, and it won't discharge spark.

 

So what you do is unplug the coil and the igniter module. Use a multimeter to check resistance across the two wires. One is purple or blue, the other is red with a green stripe. If either shows high resistance or open loop, that is likely the cause of your problem.

Ok then, So the rear half of your coil pack is not making spark. This is where those 2 wires come into play. Those wires are grounded by the igniter module, one at a time, so that the coil can build the magnetic field which creates the spark.

Those wires go from the coil pack to the igniter module on the firewall, but they go through a couple of connectors along the way. If one of them does not make a good connection, is dirty/corroded or the wire is cut or even chewed by a mouse, the igniter can't ground the half of the coil that that wire goes to, it can't build the magnetic field, and it won't discharge spark.

 

So what you do is unplug the coil and the igniter module. Use a multimeter to check resistance across the two wires. One is purple or blue, the other is red with a green stripe. If either shows high resistance or open loop, that is likely the cause of your problem.

 

so what is the rectification then ?

You stated the coil and ignitor have been replaced, though they are questionable from what I understand. Broken reluctor tabs still haven't been ruled out as far as I know also. Looking at the crank sensor signal with a scope would show if the two sets of three pulses are getting to the ECU ok.

You stated the coil and ignitor have been replaced, though they are questionable from what I understand. Broken reluctor tabs still haven't been ruled out as far as I know also. Looking at the crank sensor signal with a scope would show if the two sets of three pulses are getting to the ECU ok.

 

As an observation Cougar is THE electrically related expert here. Based on the advise I've seen him give others.

As an observation Cougar is THE electrically related expert here. Based on the advise I've seen him give others.

 

excellent , hopefully I will get this opportunity today.

Here is a good drawing showing the CPS sensor, the reluctor ring, and the signal pulses.

 

http://www.ultimatesubaru.org/forum/attachment.php?attachmentid=5007&d=1183113109

 

Thanks for the vote of confidence. The 'Cat' can wander off on the wrong trail at times but tries to pin the trouble down ASAP.

Edited May 16, 201114 yr by Cougar

Well here is where it gets to a real learning experience.

Im not well versed in electrical and I never learned how to use a Multimeter .

 

I have a Cen-Tech Digital multimeter .

I have it set at Ohms at 200

The readout says 1 on the digital display

I disconnected the coil and the ignitor and connected the leads to the blue wire and the other to the red wire.

I get no reading on my multimeter. It stays at 1 .

 

Thanx in advance for the electrical leasson Im going to get when this is all done

The number 1 displayed on the meter simply means the current resistance reading between the probes is over the scale the meter is currently set to or the resistance may be infinately high and beyond the meters capability to measure it. You will need to change to progressively higher scales in order to find out what is really true. In case you aren't aware of it, whenever you make a resistance measurement there should be no power applied to the circuit and least one leg of the device that is being tested should be isolated from the circuit so a false reading can't happen.

I think my meter may need a new battery then as I have tried using all the different Ohm settings at it sits at 1 .

When I touch the wires you have suggested , I get no reading change on the meter.

Sorry for this lack of knowledge but with a bit of patience I will understand this multimeter usage and be better for it .

Thanx

Check to see if the meter has a HOLD function. That would freeze the display. Bad meter probe wires would cause that also. Set the meter to read DC voltage and measure a battery to see if that does anything.