Ignition Timing Problem

[dorifuto.boi]

Ignition Timing Problem

Hi all,

I just purchased an R32 GTR (no modifications) and am having a few small issues that I am trying to sort out. One of the issues is that when I shone a timing light (set to 0 degrees) onto the crank pulley with the engine warm, at 950rpm, and AC off, it showed a timing more advanced than 30 BTDC. I had to turn the CAS all the way clockwise in order to get the timing to be at 20 BTDC. However, every few rotations, it would jump to a value that's not 20 BTDC. I just want to know if the ignition timing is supposed to be consistently at the same value or if it is normal for it to jump to another value once every few rotations.

Also, after turning the CAS all the way clockwise, I am getting almost no power in low revs when the car is cold (engine does not stall if I clutch in and let off gas) so I am only able to drive extremely slowly until the car is warm. The bypass valve sound is more pronounced after the CAS adjustment. There is also more afterfires after CAS adjustment.

Thanks for your time !
David

Edited November 7, 2016 by dorifuto.boi

[blind_elk]

Was the car running OK before you checked the timing? It would seem it was driving better than after you made adjustments. So why not put it back? (the old adage of "if it ain't broke, why fix it" seems to apply)

The crank pulley is marked in 5deg increments. The pulley rotates left to right, as you look into the engine bay. So the first (right-most) mark is 30BTDC.

Some timing lights somehow show double the actual timing. The safest way is inserting a spark plug lead on #1 and measuring "old school".

I don't know about the "jump".

 

 

[niZmO_Man]

How did you hook up the timing light?

[tridentt150v]

I always use a self powered timing light to remove induced/false strobes.  Try to avoid using units that reply on the vehicles own power sources.  It is the slide over clip to the wire type - I use No# 1 sparkplug wires for the trigger - the strobe is rock steady, no jumping or false positives!!!

Every mark is 5 degrees - as already stated.  Also 950 rpm sounds too high.  It is supposed to be set at 650.

 

[msammut]

David

The slide on type Timing light pickup clip should have makings to tell you which way the clip faces. Placing it the wrogn way around on No1 plug lead will give an incorrect timing reading.

 

Check this first.

Michael

 

Edited November 15, 2016 by msammut