GTR Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
450 Posts
Discussion Starter #1
Morning All
I'm looking at taking the RB26 engine covers off to get them painted up.
When taking the cam belt pulley cover off the cam sensor/housing needs to be removed can this be removed and replaced without screwing the original sensor setting up.
Thanks for any advise....
 

·
Skyline Section Manager
Joined
·
11,872 Posts
You NEED to remove the CAS if you want to remove the cam belt cover. The best way is to measure the ignition timing now, and simply re-set it after you have re-fitted the cover.
 

·
Registered
Joined
·
450 Posts
Discussion Starter #3
Thanks - Would the timing be checked, recorded and then reset using a strobe or am I completely out of date..
 

·
Registered
Joined
·
1,281 Posts
Yip - usually set at 20° - hooked up from the blue wire sticking out of the spark plug cover at the rear from memory - as R32 combat says - check the 'before' prior to removing the 3 cas bolts.
 

·
Registered
Joined
·
400 Posts
yep thats right there should a wire like a loop near the back of the ignition amplifier. Basically its plug1 on the block. Then using a strobe gun on idle point it near the crank at the bottom, there should be some marking on it. Make a note and all will be well when replacing.

Some people mark the three nuts with tipex or something similar. but its worth the hassle to do it by a strobe gun.
 

·
Registered
Joined
·
715 Posts
Who's to say its set right in the first place, most GTR's I have seen are set up wrong. Just set it to 20 degrees at base idle in consult or datascan. you might just get a better setup engine out of it.
 

·
Registered
Joined
·
2,538 Posts
Any change to the timing will affect the ignition timing throughout the rev range.

If your car was mapped in the UK you should take steps to protect the value of the mapping by carefully marking the orientation of the CAS before you remove it.
 

·
Registered
Joined
·
450 Posts
Discussion Starter #9
It was mapped by Abbey back in September, runs and starts perfectly, so dont want to alter anything.
I will carefully mark everything (bolts to sensor housing) before I start, It will be a swap over as I have a second cover on its way which will be painted.
Thanks for response.
 

·
Skyline Section Manager
Joined
·
11,872 Posts
Is there any point of marking the cover when you arn't going to put it back on?

Get a strobe light and measure the timing. Its the correct way of doing it. :)
 

·
Registered
Joined
·
450 Posts
Discussion Starter #12
I did mention, mark the bolts to the sensor housing as the covers will be changing, and I will be using a strobe without doubt... Cheers
 

·
Registered
Joined
·
1,907 Posts
I used my R-Vit as that can give you the ignition readout. Did it at idle when cold (30 degrees) and when warm (20 degrees). marked the bolt holes as well. Once all back together, checked it and was all the same :).
 

·
Registered
Joined
·
449 Posts
Alex Creasey said:
I used my R-Vit as that can give you the ignition readout. Did it at idle when cold (30 degrees) and when warm (20 degrees). marked the bolt holes as well. Once all back together, checked it and was all the same :).
Yes but if you don't put the CAS back in exactly the same place, the timing will still change, but the ecu will not know about it and will still be telling you its 20degrees at idle when warm.
 

·
Registered
Joined
·
2,852 Posts
a good thread here - I've recently changed the cambelt on my 33gtst (mostly a mate did it but I held a lamp and things!). the timing on the engine is cool but the ignition timing is obviously out.
Prior to removal of belt tho we marked the CAS on the cam cover. however we've put it all back on and it IS still out - the car shows knock spikes on the PFC hand commander when on boost (its okay off tho) and the ECU light flashes warnings.
Turning the CAS clockwise or anti clockwise didn't do anything to adjust the ignition count of 15degrees on my hand commander and I didn't realise you have to use a timing light to accurately set it so was a bit dumb.
HOWEVER with a few adjustments (like a dozen!!) I did notice the hand commander would show an initial reading whilst it warmed up then would drop to the ignition value that the CAS was adjusted to for a few seconds then would slowly increment back up (or down) to its 15degrees. When I turned it fully anti clockwise the car when fired up would hike up the ignition to say 27degrees for a moment (cold idle), then a huge drop in value to like 6degrees for a few seconds and the car could literally be heard slowing down then the ecu would slowly return to its 15degrees even tho the slow rhythm of the car could be heard. I'm guessing this 6degree mark is the point the CAS had adjusted the ignition to but not taken it as science here.

I've since put the CAS back to the markings on the cam cover and am adjusting the ignition using the pfc option7 by -4 degrees to run safely but it isn't anything like as nippy as it was and I'm staying off hard driving for the mo. I'm gonna get it over to a garage this week to get them to adjust it with a timing light properly.
 

·
Registered
Joined
·
2,852 Posts
just realised above is totally wrong - turning CAS fully anti clockwise would advance ignition massively doh! Obviously the car was making a huge adjustment and a drop in ignition timing was quite large as a result. gonna need the timing light to sort this out.
 

·
Registered
Joined
·
449 Posts
Like I said above, you can't use the PFC hand commander to set the timing, because the ECU gets it timing signal from the CAS. You will need to use a timing light to set the timing.

:)
 

·
Registered
Joined
·
8,804 Posts
Like I said above, you can't use the PFC hand commander to set the timing, because the ECU gets it timing signal from the CAS. You will need to use a timing light to set the timing.

:)
so then what effect does the PFC ignition map have? I had new plugs put in today to get rid of spark blowout at 1.4bar boost, and they strobe-reset the CAS to a "safer" timing. He told me that the car would lag a lot more but it wouldn't knock. And he was right - knock went down to peaks of around 15 at 8K rpm full boost. And the car is slow as hell now - either that or it's so obscenely fast that everything goes into slow motion :p

I've been trying to dial out the ignition retard at 4000rpm and below to increase throttle crispness and reduce lag. I think it's been working, but I've had to add up to 9 degrees of timing in some cells. Seems like an awful lot.
 
1 - 19 of 19 Posts
Top