Bosch Coil Pack Conversion - Help Needed

[GunMetalR33]

it may be your intake pipe collapsing

<{POST_SNAPBACK}>

If that was the case I would have thought that it would be worse the hotter it got, instead it only happens when cold.

[Skas33]

Hey lazy-bastard

Good to hear that you got it working.

Could you possibly post a wiring diagram, like from the plugs to coils.

Thanks

[Lazy-Bastard]

I can try to explain the wiring...when I have more time (ie: when my 1 1/2 yr old leaves home ) I will try to put up a proper diagram.

It's pretty simple really. This is all for a series 1 R33 GTST with external igniter, I have no idea about compatibility with other models.

Where the coil loom plugs into the igniter, there is another connector (with 2 wires - one thick white one, can't remember the colour of the other one) that joins into the loom. The thick white wire is the power (+12v) for the coils, and this just daisy chains from one coil to the next.

The other wire coming from the 2 wire plug loops into the cylinder 1 signal wire (I think it has something to do with monitoring timing).

There is a ground wire that connects to the back of the head and then to each coild pack. This again is a daisy chain affair, so just loops between each coil.

The only separate wires that run to each coil are the signal wires (which tell the coil when to fire) coming off the igniter. There are 6 wires coming out of the igniter, so obviously one to each coil. I can't remember the order at the moment, but I will have a look sometime soon and post the order. If you disect your factory igniter to coil loom you will be able to isolate which wire is for which coil.

The earth wire becomes redundant if you are mounting the coils on a metal bracket that connects to the chassis of the car as this will earth all the coils anyway.

I will post diagrams and more details when I have time.

Edited February 17, 2006 by Lazy-Bastard

[BHDave]

Did you get the things working properly? I tried in vain for a good 6 months with an almost identical setup and tore them out in disgust by the end.

Works fine at the bottom end, the increased smoothness was nice but mash the throttle, or make any more than about 4psi and it suffered complete ignition breakdown.

Seeing as i was in denial, i tried the following (not necessarily in order)

rewire power direct off the battery using 20 amp cable - no improvement

Swap ignitor from rb25 to rb20 - no improvement

Swap rb20 ignitor for 2 CA ignitors - no improvement

Swap fuel pump, fuel filter, remove emanage ignition loom - no improvement

Swap in a pfc - got worse as the car made more power with less boost due to the slightly aggressive base timing map which made the miss occur

Rip out external coils and reinstall stockers - massive improvement but still missing

rip out stockers, install splitfires, reinstall rb20 ignitor tidy up wiring - fixed.

I was in denial as i had a mate running the same setup on both a CA and SR silvia with stupid rich mixtures, plug gaps out to 1.4mm and no missfire.

[JamesUK]

Did you get the things working properly? I tried in vain for a good 6 months with an almost identical setup and tore them out in disgust by the end.

Works fine at the bottom end, the increased smoothness was nice but mash the throttle, or make any more than about 4psi and it suffered complete ignition breakdown.

I have them running totally fine, quite nice and simple and with good results. I'm using an RB20 ignitor pack on my RB25 series II

If you have tried all that and you are still having missfire problems, then the problem is something else. If everything seems to be running fine on idle and light throttle, but just gets all farty and missfirey on boost, then I suspect your problem is a boost leak. Obvious places are the intercooler and the actuator pressure hose...

Hope this helps,

James

[BHDave]

That was all fine too. Installation of the splitfires had everything running perfectly both on and off boost with no other changes.

What model coil are you running james?

[spx25t]

SK, I am using a series 1 R33 ecu.

I have heard there are issues with the dwell time from someone else, but other people who have done the conversion don't seem to have an issue.

http://www.skylinesaustralia.com/forums/in...topic=89824&hl=

I believe the bosch mec717 are a single coil, so would I be right in assuming that this is NOT a wasted spark setup?

Hi all I am the guy who posted the link lazy bastard refers back too.

Since fitting my coil setup over a year ago I have not had a single problem with the setup

with mine i am still running a standar ignitor from a series 1 RB25. my friend and I just took it off the galley cover and mounted it underneath the coil packs. I am like Lazy in that I know nothing about wiring. so my friend did that side of things.

but for cost and simplicity it has been the best $300 I have spent also Changing plugs is SOOOO much easier now it is not funny.

I would love to be able to give you guys a detailed account of how my friend did the wiring but unfotunately he is Lazy himself and half of what he says goes STRAIGHT over my head.

So all the best

I will try over the weekend to get some better pictures of my setup with a close up of the wiring.

but will have to work around being at autosalon this weekend.

[Lazy-Bastard]

Well, for the moment I have gone back to the fctory coil packs under advisement from my tuner.

The Bosch coils seemed to be running fine, although I did have to gap the plugs to .6

I installed a powerFC and took it to get tuned. The tuner insisted on using Denso Iridiums, so I went with his advice. He says he has tuned 20+ skylines with the factory coil packs and NEVER had a problem.

Soooo he started tuning with the Bosch coils and the Denso's gapped at .8 but couldn't run any more than 1 bar and it was still breaking down on full throttle. It would rev cleanly to redline under half/three quarter throttle, but on WOT it would still crap itself.

I needed the car back (daily driver) so he had to stop there, but he suggested I go back to the factory coils and see if the miss disappeared. I did so, and with the same plugs and gap the miss improved was wasn't completely gone.

I swapped the plugs for a set of NGK Iridiums that I had which had only done 500k's or so, and gapped them at .6. Miss GONE at 1 Bar.

That was about 1 1/2 weeks ago and everything has been running pretty well, but I took it for a drive last night and the miss is BACK at WOT. Not as bad as with the Bosch coils but under the same types of conditions.

I have a pretty strong suspicion that there is a voltage drop or an earth leak under heavy load, so I'm going to give it back to the tuner and see what he can find.

I am still in denial.........

Edited March 16, 2006 by Lazy-Bastard

[xr8eater]

that is the exact same problem i had lazy-bastard im thinking of geting split fires or changing the igniter

[JamesUK]

Installation of the splitfires had everything running perfectly both on and off boost with no other changes.

What model coil are you running james?

hmmm, weird

I have the same as the G0Dz1lla guy sells and all is sweet, but I am running pretty low boost (0.9 bar)

[Lazy-Bastard]

yeah.....pretty pissed off.....for the cost involved in the Bosch conversion I could have almost bought a set of splitfires

[Lazy-Bastard]

Defeat..........

miss has gone completely at .8 gap on denso iridiums

$535 delivered from Perfectrun. Ordered on Tuesday and received the following Tuesday morning.

Edited March 30, 2006 by Lazy-Bastard

[xr8eater]

i was having a good think about the way our engine were behaving and thought it may be the heat range of the plugs. Do you know the heat range of the denso iridiums?

[Lazy-Bastard]

im pretty sure they are a 6

[GunMetalR33]

I run 7's in summer and 6's in winter. In summer with the 7's gapped at .8mm I get some misses on coolish morings but they go away once I get a bit of boost onto the sparkies.

Also, I found that adding a deg of timming where the missing is occuring in the ign map has helped a lot.

[xr8eater]

for climate reasons where are you from gunmetalr33

i noticed less missing in the colder weeks in cairns

[GunMetalR33]

Canberra, thus the cold mornings thing