Got Splitfires, And 1.0mm Gap=missfire (update) 0.8mm

[grandmasterb]

NO probs GMB, you can have it anytime, aslong as you don't try and do any standups in it. LOL.

Well it's wasn't just the ecu, but the central 20 one rock. In first the thing just wheel spins, and second, yeeehhhhaaaaaaaa.

Go to check the AFR's, but the guy who i got the ECU form has a dyno from KUTSIE, and kutsie said that it actually runs quite ritch

What are you trying to say Wog...

Are you calling me a hoon

Glad you got it sorted though, i know what its like to have a missfire and try absolutly everything you can think of and then some to get rid of it

[WogsRus]

i know your a hoon. LOL, it's in the blood, especially having bikes like you and I.

So far so good, i think the car might be a bit lean, so pumped up the fuel pressure a bit and see how it goes.

[iz32]

hey guys.

this thread has been a really good fault finding read and has giving me a few more ideas to chase down the cause of the misfiring problem but one question... what is R&R?

[WogsRus]

Ritch and retard, the car sees too much air flow and retards the timming and as a result adds extra fuel cousing boost droop

[iz32]

ok so would outside air temp effect this? even tho boost pressure is the same?

i.e 35 degree day will boost to 1.3bar very slight misfire yet a 28 degree day will misfire like buggery on 1.3bar.

btw been down the coil pack and plug gap path already with no luck.

[sik14]

i got irridium plugs a few months ago, my car started playin up a few weeks later. on the packet it says NOT TO CHANGE THE GAP. its almost like under load boost blows the spark out. has any1 else had this problem?

[RB30-POWER]

ok so would outside air temp effect this? even tho boost pressure is the same?

i.e 35 degree day will boost to 1.3bar very slight misfire yet a 28 degree day will misfire like buggery on 1.3bar.

btw been down the coil pack and plug gap path already with no luck.

absolutely, the cooler the air the denser (more air sensed by air flow meter) means the rich and retard effect will happen sooner.

stock ecu's are useless on modified vehicles unless they are chipped.

[madaz R33]

wogsrus, i have the very same issue atm, tried a number of things as u did, but have come to the conclusion that i also need a new ecu-- lucky i have a power fc ready to go in! thanx for posting up all ure info, Damo (fellow Tassie guy!)

[RANDY]

So... I have the same problem as of 3 days ago. Replaced my iridium plugs today, and it's slightly better. Nothing has changed, and the car is pretty darn stock (10psi though).

I'll keep this post updated.

[Rolls]

Get a remap, I bet its running way to rich. That was the cause of mine and alot of other misfires. The ultra rich condition often brings the worn coil packs to their knees hence new coil packs/plugs fixing the issue.

[The Alchemist]

One thing to check is voltage at the coil from the ignition relay. You need to use a scope as a voltmeter is not fast enough to "see it".

Anything larger than a 1/2 V drop from battery voltage is cause for concern. This robs the coils of charging voltage and current and can cause a high rpm/high boost misfire.

Skylines are old vehicles and so is the wiring, relays and connectors. One length of wiring from the ignition fuse in the engine bay around to the large multi plug by the airflow meters was losing 0.8Volts in my GTR!!! Once we reached the coils it was down to 12V each time the coils fired.......

Worth a look...

Mike

[WogsRus]

So how do i test all this, or more to the point when i go to see a electrician what do i say to hi to test?

[The Alchemist]

hi,

the power supply to the coils is the 3 wire plug at the back of the GTR tappet cover, left hand side. Its easy to identify as it is a 3 wire, 2 being black and the center one being a large white wire. This is the power supply. Simply hook up the scope to back probe this wire, set sample time to around 10 to 20ms and have a look at what the voltage is doing.

If it sits on 14v battery then drops down as the coil charges, measure the voltage drop. Anything over 0.5V means your coil charging will be compromised, even if you increase the dwell (charge) time this won't compensate for low charging voltages.

Mike

PS, I see you have a GTS-T. The principle is exactly the same though. To locate the 12V feed, unplug a coil, turn the key on and look for battery voltage on one of the 3 pins, trace the coil loom back to the main multiplug and locate the 12v feed and back probe there.

Edited July 3, 2007 by The Alchemist