Car Has Fried 2 Ignitor Modules!

[BoostedBarge]

Hey guys, I'm after your advice. I have a Stagea 260RS with an RB26DETT from an R33 GTR. 2 weeks ago the car just cut out. We found that the ignitor module was dead, so ordered a new one from Nissan for $800! The car ran fine for 2 weeks and then the same thing happened again last night. Not happy! Any idea what might be killing the ignitor module? I pulled out the coil packs and measured the resistance on the primary and they were all around 0.8ohm, which looks good. I checked the grounding, power supply and also checked I was getting a good signal from the ECU and it all looks good. Any ideas? I really don't want to put another ignitor in there and then have it die on me again.

[BoostedBarge]

I also pulled out a coil and spark plug to check I was getting a spark (grounded it on the coil mounting plate). Got nothing...

[Gav]

Some questions:

How have you diagnosed that the ignitor is "dead"?

Have you substituted a set of known working coils with you ignitor? While you are at it, substitute a known good harness also. Double check the earthing eyelet is both well connected to the harness and is cleanly ground?

I assume you're not running an HKS Twin Spark (or other CDI pack)?

Finally, I don't pay heed to the Nissan manual's method of diagnosing by measuring resistance - I've had failed coils return exactly the same readings as good coils.

PS - there should be some warranty on the ignitor from Nissan.

[GTRNUR]

Bad ground. Check you have at least 2 good grounds from the engine to the chassis. Loosen them off, give them a wiggle and tightten them up again.

A bad earth causes the ignitor to not be able to switch max current to the coils. It can also cause the ignitor to burn out as the earth signal drifts around.

[BoostedBarge]

Thanks for the feedback guys. I don't have a set of coilpacks to swap over, but I should be able to get some from my mechanic. When the first ignitor died, he just swapped it over with a known good one, and it all came good. So no need to investigate any further. I was away last week, so just bit the bullet and bought the new one to get the car going for my wife.

I'll take a good look at the earths tomorrow. Might need to look into that Nissan warranty... thanks

[BoostedBarge]

Well I just went out and checked the earths. They were all tight. I loosened them and tightened them again as GTRNUR suggested. Trying to track down another ignitor now...

[Gav]

My money is on a dodgy coil. Sometimes a newer (i.e. stronger) ignitor will mask a bad coil for a while. Borrow a set of known good coils and see if that makes a difference. If you are still using the original OEM coils it may be time for an upgrade anyway.

[BoostedBarge]

Well, I've bitten the bullet and ordered a set of Splitfire coilpacks. If they're not dead already, it's only a matter of time, so I'd may as well replace them now. Fingers crossed this fixes the issue.

[BoostedBarge]

Well it's been a bit over a month since I replaced the coils and the car has probably done over 1000km and has been running great. Until today.....

Exactly the same issue. Engine just cut out. I haven't had a look yet, but I'm 99% sure the ignitor module is fried again. Not happy at all!! I have bought 2 ignitors now ($1500), plus a set of Splitfire coil packs and now it looks like I'm up for another ignitor

I'm not sure if it's a coincidence, but all 3 times it has died under similar circumstances: cruising down a hill (overrun fuel cut would have kicked in), get to the bottom, go to accelerate and find it is dead. It has a Vipec ECU (has been in there since November/December last year without any problems). I've emailed them already to find out if they have any ideas.

[Simon-S14]

im guessing it has something to do with the ECU your running....

exactally what tho. im unsure of.

[Simonster]

Well it's been a bit over a month since I replaced the coils and the car has probably done over 1000km and has been running great. Until today.....

Exactly the same issue. Engine just cut out. I haven't had a look yet, but I'm 99% sure the ignitor module is fried again. Not happy at all!! I have bought 2 ignitors now ($1500), plus a set of Splitfire coil packs and now it looks like I'm up for another ignitor

I'm not sure if it's a coincidence, but all 3 times it has died under similar circumstances: cruising down a hill (overrun fuel cut would have kicked in), get to the bottom, go to accelerate and find it is dead. It has a Vipec ECU (has been in there since November/December last year without any problems). I've emailed them already to find out if they have any ideas.

What new wiring has been done in the engine bay/car. Has there been any new sections that were soldered? I had a similar thing happen to me where an electrical short fried my CDI (Autronic) I pulled the coil wiring apart and found a solder joint that had a little peak which rubbed through the wire insulation and bang. Although mine didn't cut out entirely but was running on 2 cylinders.

Have a good look at the wiring- i know it's a pain in the ass but hopefully you can remove the wiring as the cause if you find nothing?

Hope that helps.

[Swiper the Fox]

What new wiring has been done in the engine bay/car. Has there been any new sections that were soldered? I had a similar thing happen to me where an electrical short fried my CDI (Autronic) I pulled the coil wiring apart and found a solder joint that had a little peak which rubbed through the wire insulation and bang. Although mine didn't cut out entirely but was running on 2 cylinders.

Have a good look at the wiring- i know it's a pain in the ass but hopefully you can remove the wiring as the cause if you find nothing?

Hope that helps.

my bet is the coil loom...these things get very brittle with heat and this hardens the insulation which causes it to flake and expose the conductor. This shorts the output causing extremely high current which frys the power transistors in the igniter.

[BoostedBarge]

I spent a fair bit of time going over the loom last time I had this problem. All of the connectors are in good condition. None of them have become brittle yet. I also spent some time measuring for shorts while shaking the loom to see if there were any problems. Very frustrating problem this one...

[Swiper the Fox]

I spent a fair bit of time going over the loom last time I had this problem. All of the connectors are in good condition. None of them have become brittle yet. I also spent some time measuring for shorts while shaking the loom to see if there were any problems. Very frustrating problem this one...

its not in the connectors...im talking about the coil loom itself. You will not be able too see the damage (if any) unless you remove the grey tape. When you have installed the coils you may have moved the loom around separating the possible damage site. With engine movement the damage has moved close enough to short out again. Ive seen this problem before and it normally occurs at the bend in the loom near coil 5.

not saying this is 100% what it is but id untape the loom and do an inspection.

Edited October 11, 2009 by DiRTgarage

[BoostedBarge]

Well the car is running again. I cut open the ignitor module and found the PCB track to the ground pin had burnt out. I soldered in a piece of wire and it's running again. Who knows how long it will run for..

The question is, why is the ground track on the PCB burning out? This is the only ground for all 6 transistors and it burnt out after number 6, hence I lost all transistors.

[blur]

Too much coil current could cause this, maybe short in the wiring or too long dwell time on the coils. Is the ignitor earth good, wouldnt hurt to run another to it just in case.

[BoostedBarge]

OK, as promised here are the pics of the ignitor modules. I owe a thanks to FastRotor who's been offering me advice about this problem.

Bit of a how-to guide:

1. Cut open the box around the top, about 5mm in from the edge. I used a Stanley knife and only managed to cut myself twice

2. The inside is filled with this sticky silicone-like clear substance. You can poke your multimeter through it to determine the dead track. You can see my dead track on the top left (it's a bit burnt). This is where the last transistor connects to the ground pin. The current from the emitter on each of the 6 transistors flows through this piece of track.

3. Peal back the sticky sealant.

4. Solder a bit of wire over the broken track. The solder Nissan have used is quite hard and requires a fair bit of heat to melt it. I had my soldering iron set to 400 degrees to melt it.

5. Once you're happy with your wire you can place the sticky sealant back down over the top of it. Be careful of the little silver leads they are very fragile.

Quite an interesting design inside that little box. I've never seen transistors that look like that and definately haven't seen a board covered in that sticky silicone stuff.

[BoostedBarge]

So I guess the question now is: what fried that little piece of track.

It's got to be one of 2 reasons:

-Too much current

-More than 2 transistors on at once. The ECU I'm using runs wastespark, so there are 2 transistors on at once. This means twice the current through that track. Heaps of people have run this before, so I doubt it's a problem. However, if for some reason I got a short on the input or an ECU fault, I could potentially switch on 4 or 6 transistors.

-Short across the primary on one coil pack. If I got 12V shorted across the primary then you'd have a short through one of the transistors. Would the single transistor fail instead of the ground link? I've stripped back the loom and it looks OK, the coil packs are brand new, so this doesn't seem like a likely cause. I've also measured the resistance between ground and the battery and it is 0.1ohm, so looks good to me. Unless there's a loose connector somewhere. I tightened the ones I could access last time I had this problem.

-Higher alternator voltage. That combined with wastespark would mean more current. The max voltage I saw today in the logs was 13.87V so that looks OK.

-Too much dwell

-I just went for a drive and had a look at the log. The dwell is sitting at 1.8-1.9ms with a max of 2.7 at some point, so it looks OK. A dodgy CAS might cause the dwell to go high at some point..

-One of the inputs is jammed on for some reason. I guess this could cook the ground track or the transistor or the coilpack. Who knows?

So that's all I can think of. Anyone got any other ideas? I think I'll fix my other broken ignitor and drive around with it in the glove box in case of an emergency.

[Swiper the Fox]

So I guess the question now is: what fried that little piece of track.

It's got to be one of 2 reasons:

-Too much current

-More than 2 transistors on at once. The ECU I'm using runs wastespark, so there are 2 transistors on at once. This means twice the current through that track. Heaps of people have run this before, so I doubt it's a problem. However, if for some reason I got a short on the input or an ECU fault, I could potentially switch on 4 or 6 transistors.

-Short across the primary on one coil pack. If I got 12V shorted across the primary then you'd have a short through one of the transistors. Would the single transistor fail instead of the ground link? I've stripped back the loom and it looks OK, the coil packs are brand new, so this doesn't seem like a likely cause. I've also measured the resistance between ground and the battery and it is 0.1ohm, so looks good to me. Unless there's a loose connector somewhere. I tightened the ones I could access last time I had this problem.

-Higher alternator voltage. That combined with wastespark would mean more current. The max voltage I saw today in the logs was 13.87V so that looks OK.

-Too much dwell

-I just went for a drive and had a look at the log. The dwell is sitting at 1.8-1.9ms with a max of 2.7 at some point, so it looks OK. A dodgy CAS might cause the dwell to go high at some point..

-One of the inputs is jammed on for some reason. I guess this could cook the ground track or the transistor or the coilpack. Who knows?

So that's all I can think of. Anyone got any other ideas? I think I'll fix my other broken ignitor and drive around with it in the glove box in case of an emergency.

dont forget about the base current from the ecu to switch the transistor. This current also goes to ground through that track.

[BoostedBarge]

dont forget about the base current from the ecu to switch the transistor. This current also goes to ground through that track.

Ah yeah, good point. Haha