Need Some Help

[mango]

grand son has a 1988 ti skyline with rb 30 motor, while the motor is idleing i kind of surges.

he has changed the leads and plugs and it still does it.

he has taken 1 lead off at a time and there is a difference in the motor as it ran rougher, except when he took off no 3 lead there was no difference.

he then took no 3 plug out and shorted it on the rocker cover and there was plenty of spark. the plug was black at the bottom, it was like it was not burning petrol, there is plenty of compression in the cylinder, because it is getting petrol i pressume that injector is ok.

he has also put fire injector cleaner in with the fuel, it has nulon motor flush in the oil, and new exhaust system on it.

the car had been sitting for about 6 months without being driven.

hope someone can head him in the right direction.

thanks,

mango.

[Nosmo]

grand son has a 1988 ti skyline with rb 30 motor, while the motor is idleing i kind of surges.

he has changed the leads and plugs and it still does it.

he has taken 1 lead off at a time and there is a difference in the motor as it ran rougher, except when he took off no 3 lead there was no difference.

he then took no 3 plug out and shorted it on the rocker cover and there was plenty of spark. the plug was black at the bottom, it was like it was not burning petrol, there is plenty of compression in the cylinder, because it is getting petrol i pressume that injector is ok.

he has also put fire injector cleaner in with the fuel, it has nulon motor flush in the oil, and new exhaust system on it.

the car had been sitting for about 6 months without being driven.

hope someone can head him in the right direction.

thanks,

mango.

Hey mate,

Had a very similar thing on an R31 GTS I was trying to tune...

Ended up being the distributor cap. I could not see anything wrong with it, however when I swapped it for another one the car came good, set the time and the thing goes like a dream!

However, the first thing I would do is find a nice quiet road and give it a bit of a work over. RB30's do not like sitting around much.

Other than that start looking at the all vacuum hoses, inlet tract etc.

Also try forum.r31skylineclub.com for more info.

Cheers!

Jamieson