Dwell Timing

[Justlikemusic]

What is the standard dwell timing on the RB25DET coil packs? And how much would this differ from Series 2 commodore coilpacks with Eagle 9mm leads?

People have done wasted spark setups and run them fine... yet when I do it and it doesn't run right I get critisized and told to put it back to standard.

I don't really like the design and want to run external packs since I think they would give extra parts. I have tested the spark, it has spark on all 6 cylinders. I have replaced the igniter, replaced the AFM... all runs the same. Turned the CAS and injectors fire, there is fuel pressure in the rail.

ECU gives me code 55.

Car starts and idles very poorly with the wasted spark setup.

The plugs foul up relatively quickly. I cleaned them with carby cleaner and sanded them shiny, set 0.8mm gap and still starts and idles crap straight away.

Next step be check with a gauge for vacuum leaks? I have looked over and all the hoses are connected properly from what I can see. Will a crack/split in a intake/vacuum hose make it run really rough, and make it not want to idle properly and not rev at all under load and stall?

Timing has been set to 15 BTDC with a light last week, CAS marking is in the same spot as it always has been.

What would be my next steps other than changing back to standard coilpacks? (Because this is going to cost me $300-500 just for loom and coilpacks)

[toffy]

lol it's not a old holden 6 . check for induction pipes cracked/slit or not properly connected , sounds like limp mode or you got the wiring wrong?

[rob82]

What is the standard dwell timing on the RB25DET coil packs? And how much would this differ from Series 2 commodore coilpacks with Eagle 9mm leads?

People have done wasted spark setups and run them fine... yet when I do it and it doesn't run right I get critisized and told to put it back to standard.

I don't really like the design and want to run external packs since I think they would give extra parts. I have tested the spark, it has spark on all 6 cylinders. I have replaced the igniter, replaced the AFM... all runs the same. Turned the CAS and injectors fire, there is fuel pressure in the rail.

ECU gives me code 55.

Car starts and idles very poorly with the wasted spark setup.

The plugs foul up relatively quickly. I cleaned them with carby cleaner and sanded them shiny, set 0.8mm gap and still starts and idles crap straight away.

Next step be check with a gauge for vacuum leaks? I have looked over and all the hoses are connected properly from what I can see. Will a crack/split in a intake/vacuum hose make it run really rough, and make it not want to idle properly and not rev at all under load and stall?

Timing has been set to 15 BTDC with a light last week, CAS marking is in the same spot as it always has been.

What would be my next steps other than changing back to standard coilpacks? (Because this is going to cost me $300-500 just for loom and coilpacks)

You have obviously f**ked something up. Most likely a wiring issue but who knows without looking at it. It amazes me what big things untrained people can miss and or overlook. Car should run fine with std dwell settings. Time to tow it to someone that knows what they are doing.

[Justlikemusic]

lol it's not a old holden 6 . check for induction pipes cracked/slit or not properly connected , sounds like limp mode or you got the wiring wrong?

So a little slit in the induction pipe will cause it to run like crap and not be able to drive without dying in the ass? I didn't think that sort of thing would make that much of a deal...

Wiring is perfect to digrams I have seen and tested for continuity with a multimeter. I understand the principle on how the spark setup work and which wires go where and why. I'm thinking I've rooted a hose or something somewhere around, since it has the same symptoms with the standard loom and coilpacks.

Edited March 29, 2011 by Justlikemusic

[tm_r33]

why is every one changing to wasted spark set up? oem coil packs at race track temps with big boost and high hp can work well.

If your 15 - 20 year old coil packs are failing its because they are old and your car hasnt really done 80 000 km's its done 200 000. NOT because nissan designed a bad ignition system. Its a high performace engine.

they have been delivering spark to a boosted chamber for at least one decade.

your car probably hasnt done what the odo shows.

your car probably sat at a yard or warf in japan for months on end whil everything went brittle.

the copper in your coil pack harness is old

ive had great sucess with oem coils in multiple engines/cars

yes rb engines do suffer from misfire sometimes but there is no prob with coil on plug system.

[Justlikemusic]

Surely though the Commo coilpacks put out a fatter spark, run cooler and have less problems after I have upgraded them to MSD units... Car has done 132,000km's actually. I bought the coilpacks for $10 which were in good nick, mates rates... and the leads I had from my Falcon sitting here which were expensive too. Didn't want to spend $500 on splitfires when I could fix it for $40 worth of cable/brackets/wiring/plugs. Im sure the problem is vacuum hose split somewhere.

[Guilt-Toy]

try another afm, they are very temprimental, even if they are sitting the wrong way they can make the engine run like crap. try moving the afm around or something

[MrStabby]

So; you have a series 1 motor with the external ignitor pack and have connected the output of that to the commo coilpacks which presumably have built in ignitors. Off the top of my head i cant tell if that will cause a problem, but have you thought it through? Do you understand how transistors work?

[DVS JEZ]

^^^ are you saying to try it without the ignitor and just wire the output of the ecu straight to the como coil packs?

like above but it may not be an issue with the spark at all, maybe there is something causing the car to run excessively rich?

What ecu are you using

[Justlikemusic]

replaced the AFM... all runs the same.

try another afm, they are very temprimental, even if they are sitting the wrong way they can make the engine run like crap. try moving the afm around or something

Tried that already too...

S2 Commo coilpacks sit on top of the DFI module which I assume is their "built in ignitor". This has been removed so they are a basic twin tower coil. Same plugs and wiring as used in the "RB20DET Commodore S2" DIY writeup, except with S1 Skyline harness wiring.

Using standard ECU...

[MrStabby]

^^^ are you saying to try it without the ignitor and just wire the output of the ecu straight to the como coil packs?

Without applying any brainpower, that would seem the most obvious way to set it up to me. I'd want to make sure that the commo and nissan ECU's use similar signals to the ignitors before doing it tho.

[MrStabby]

S2 Commo coilpacks sit on top of the DFI module which I assume is their "built in ignitor". This has been removed so they are a basic twin tower coil. Same plugs and wiring as used in the "RB20DET Commodore S2" DIY writeup, except with S1 Skyline harness wiring.

I *think* you can tell if it has a built in ignitor by the number of earth connections on the coil itself. For some reason they seem to use separate earths for the signal and power circuits. I dont know enough about electronics to know why they bother doing it that way.

[Justlikemusic]

Coilpack is grounded via the bolt hole (there is a contact there) - other connection is straight power. Maybe sending power through a signal cable isn't ample to provide good power to the coil at a quick instance.

The DFI module which the three coils sit on (with spade connectors into it) is the commo's igniter. You remove this and put spade connectors on the bottom of the coilpacks and run it with the skyline setup.

Tomorrow I'll get new plugs for it... some BKR6E's and will resize the spark leads so they have a very very tight connection over the spark plug. At the moment they feel like they clip on and are a bit loose.

[Justlikemusic]

Possibly a fouled O2 sensor?

I changed extractors on my Falcon a year ago and the new O2 sensor was shot... car run like ass. I guess it can't hurt to keep buying these bits and work out what it is. I'll have spares in the future and I plan on keeping the car for some time.

[Justlikemusic]

Replaced the plugs, started it up and idled bad straight away. I have a replacement O2 sensor to go in it tomorrow when I get a suitable spanner to remove it.

I disconnected the o2 sensor and it idles the same... will this be any indication that it has gone bad?