Rb30det With Wasted Spark

[nizmonut]

ok so i finally got sick of the skyline coils and set up a wasted spark conversion using the 3.8 buick coil pack(new) and bocsh ignition leads(new) on my recently rebuilt Rb30det GTs4.

one advantage to this is now i can use a timing light to check the timing.

the disadvantage now is that when i have the timing light on the number one is firing about 10 millimeters past the last mark on the harmonic balancer.

or around 32-35 degrees past where it should be...

ive tried resetting the ecu, tinkering with the cas(but it limited to how far it can turn).

i even took the cam belt of and advanced the exhaust cam by three teeth to compensate for the retarded timing but to no avail. it still runs like dogs balls.

any help would be apprieciated, i'd hate to think i have to go back to the individual direct fire set up...

[nick81xd]

Have you checked that the harmonic balancer hasnt spun?? thats usually the cause of timing marks way around from point.

also you can check timing with light on a indiviual coil setup there is a wire loop up near the back of motor you put the clip on

[nizmonut]

Have you checked that the harmonic balancer hasnt spun?? thats usually the cause of timing marks way around from point.

also you can check timing with light on a indiviual coil setup there is a wire loop up near the back of motor you put the clip on

yeah i realize that, and no it hasn't spun the mechanical timing is fine.

its just the electronic side of it.

[Guilt-Toy]

try a different timing light ?

[Adriano]

Undo the three bolts that hold the cas on, and turn it till the timing is right, then see how it runs. I would put a scope on the ignition circuit and check the dwell/ coil saturation.

[QWK32]

your running a wasted spark setup. your going to get a double reading.

Edited April 15, 2008 by QWK32

[Duncan]

wouldn't double spark read half timing not double?

[nizmonut]

i undid the three bolts and turned the it around till the light it the marks and it runs fine as revs fine as.

only problem is its that far around ya cant bolt it back on.

double reading is correct how ever

nethier 1 or six, or any of the light pulses land where the should when the should.

when the CAS is bolted in place.

it would read like it was running twelve cylinders, each cylinder fires twice per revolution rather than the direct fires one.

had some success. pulled out the spark plugs and gapped them to .8 of a mill.

brought the timing back a bit but still not enough.

[Adriano]

Changing the plug gap wont make any difference to the timing, and wasted spark will still run the same timing. Its in the conversion to wasted spark where you have got the problem, what ignition module/igniter are you running? Souds like you have it triggering off the leading edge of the pulse instead of the trailing.

[QWK32]

what ignitor and ecu are you running? you have a rb30det so i'm assuming your running an aftermarket ecu.

and the cylinders are firing twice in one revolution of what? the cas or the engine crank?

[nizmonut]

Changing the plug gap wont make any difference to the timing, and wasted spark will still run the same timing. Its in the conversion to wasted spark where you have got the problem, what ignition module/igniter are you running? Souds like you have it triggering off the leading edge of the pulse instead of the trailing.

helilujah. its a new coil pack and leads that would normally go on a 3.8 litre vt holden vommodore.

the question is how do i get it firing from trailing edge?

oh its running my old hks f con pro, r32 igniter gtr 6 speed box, gtr intake 90 ml throttle body , custom exhaust manifold garrett 35/40 teal 40ml waste gate hks step 2 cams bocsh 740cc injectors, in a 92 gts4 shell. just stuff i had lay'n around

after i bought my god

Edited April 15, 2008 by nizmonut

[SKiT_R31]

Make sure the igniter is earthed properly (bolted down, maybe with a proper earth wire connected also), I've heard of them severely retarding if not earthed properly.

To move the timing to where it wont bolt, you need to take the CAS off, turn it as far as you need then put it back on

[QWK32]

helilujah. its a new coil pack and leads that would normally go on a 3.8 litre vt holden vommodore.

the question is how do i get it firing from trailing edge?

oh its running my old hks f con pro, r32 igniter gtr 6 speed box, gtr intake 90 ml throttle body , custom exhaust manifold garrett 35/40 teal 40ml waste gate hks step 2 cams bocsh 740cc injectors, in a 92 gts4 shell. just stuff i had lay'n around

after i bought my god

ok. so was the car running fine before you did the wasted spark modification? or does the car still run ok but you are getting a funny reading?

to change weather it fires from a leading edge to a falling edge is in the ecu setup, and it all depends on the cas disc you are using, some are leading edge discs and some are falling edge cas discs, i believe the standard RB ones are falling edge.

[Adriano]

Im surprised you are having troubles, as you are using the standard igniter, thats usually where the trouble occurs. I would get someone to put it on one of the old school scopes, and check your primary and secondary voltages/waveforms.

[nizmonut]

got it sussed out, talked to the local auto sparky about it and he gave me a diode to solder in between

what would have been number one trigger wire and number six trigger wire.

so the sensor wire that ran from number one coil on the original setup to the ecu is still connected with

it s number one cylinder trigger wire,

but before it joins the number six trigger wire on there way to the shared coil the diode has been installed to stop the pulse from number six from upsetting the signal....to the ecu......

ya'll understand that

Number one trigger wire from igniter>>>>>sensor wire joins>>>>>>diode installed here>>>>>Number six trigger wire joins from igniter>>>>>>>both join coil

thats the best i can explain it with out pulling the online colins world dictionary.

[STLKHR]

THE DIODE IS STOPPING ANY FEED BACK DOWN THE OTHER ECU SIGNAL WIRE! YES SIMPLE FIX. GOOD THOU.. IM BUILDING A BRAND NEW IGNITOR PACK FOR ALL S2 MOTORS

got it sussed out, talked to the local auto sparky about it and he gave me a diode to solder in between

what would have been number one trigger wire and number six trigger wire.

so the sensor wire that ran from number one coil on the original setup to the ecu is still connected with

it s number one cylinder trigger wire,

but before it joins the number six trigger wire on there way to the shared coil the diode has been installed to stop the pulse from number six from upsetting the signal....to the ecu......

ya'll understand that

Number one trigger wire from igniter>>>>>sensor wire joins>>>>>>diode installed here>>>>>Number six trigger wire joins from igniter>>>>>>>both join coil

thats the best i can explain it with out pulling the online colins world dictionary.