Anyone played with cams on a CA18DET?

[RB30-POWER]

check the harmonic balancer keyway etc as well.

also check the rubber in the middle of the balancer is good.

if the crank pulley was missing the key the timing could appear to move because the pulley is turning and moving the mark on it.

unlikely as you would have issues with the belt but better eyeball it's all good whilst apart.

[matt b]

Cheers mate will do

I have a couple of spare motors so I might throw the harmonic balancer and water pump pulley on from one of them after checking everything. Can't hurt!

[260BC]

CAS drive OK? But going on what you said about the ECU indicating the correct timing when its not I still think its not mechanical. If the fault still can't be located a replacement aftermarket ignition sytem may be the go.

[matt b]

CAS drive OK? But going on what you said about the ECU indicating the correct timing when its not I still think its not mechanical. If the fault still can't be located a replacement aftermarket ignition sytem may be the go.

CAS drive seems to be OK Richard but I have pulled the exhaust camshaft from one of my spare motors. I will compare them when I have time to work on the car again.

I tried in vain to remove the harmonic balancer from a spare motor this afternoon. Stuffed if I know how to get it off when there's no gearbox.

I will order some adjustable cam gears and a CAS mount from Growly this week and try to have it all back together for a test over the weekend.

[Speedyblue]

Air powered rattle gun. That'll take it off no problems.
NA cams are only worth the trouble if you get them free.
Check secretdrift.com.au tech section. The site is full of dickheads, but some are rahter cluey on engines. They are a great source of cheap parts too because none of them have any money. Cams come up everynow and then, normally when someone buys a set then lunches their engine before installing them. They then sell them to fund a rebuild...

[GTSBoy]

I was under the impression that the knock retard was in two stages on the Nissan ECUs, with the first stage being able to be bypassed via Nistune but the second, really savage stage not being able to be bypassed. I was also under the impression that when it happens the ECU continues to report the targetted timing in the timing lookup table and not the actual timing that it is outputting.

I pretty much guarantee you that if you were to do something simple (relatively simple anyway) like wire up a Microtech instead of the Nissan ECU that it would not happen.

[vet 180]

CAS drive seems to be OK Richard but I have pulled the exhaust camshaft from one of my spare motors. I will compare them when I have time to work on the car again.

I tried in vain to remove the harmonic balancer from a spare motor this afternoon. Stuffed if I know how to get it off when there's no gearbox.

I will order some adjustable cam gears and a CAS mount from Growly this week and try to have it all back together for a test over the weekend.

That spare exhaust cam you have....use it on the intake!

Then skip your intake gear 1 tooth adv. You shouldn't need gears.

I have personally done the ex and tooth skip and can tell you it works and works well. Best mod for any turbo up to around the t28 size.

[matt b]

Thanks for all the help guys. Very much appreciated. I haven't had a chance to touch it since the weekend due to work commitments but I will have another crack this weekend. Fingers crossed.

[260BC]

I was under the impression that the knock retard was in two stages on the Nissan ECUs, with the first stage being able to be bypassed via Nistune but the second, really savage stage not being able to be bypassed. I was also under the impression that when it happens the ECU continues to report the targetted timing in the timing lookup table and not the actual timing that it is outputting.

........................

I don't understand that but as you are usually right I better be careful If the timing output from the ECU is correct how can it be changed later? To my simple mind that would require a stand alone device operating independantly of the ECU. Which of course is possible but why do it that way? Just seems to be an unnecessary additional complication to me.

[GTSBoy]

I wasn't suggesting that the ECU had some device that changed the timing after it was output and reported via the Nistune software. I was saying that I think the Nistune software outputs the timing value that is contained in the lookup table for that load/rev (actually the interpolated value from the nearby 4 cells) on the basis of the assumption that all else functioning correctly, what is asked for by the ignition map will be what the ECU outputs. But in reality, the hefty chunk of timing taken out when the knock sensor stuff goes crazy is done by the ECU without there being a way to report that it's happening except perhaps by the DTC flag that is raised saying that knock has occured*.

The point is that the ECU is a factory ECU, not intended to talk to anyone at any stage in its life, so the designers probably saw no need to output the actual ignition timing value.

*I'm not sure what flags are raised, it's been a long while since I played with mine.


I may well be wrong, but as I said, I was under the impression that this is the way the Nissan ECUs did things.

One could always e-mail Matt at Nistune and ask his opinion on the matter.

cheers

[260BC]

See what you are saying Brad, you have raised a WTF point there.

[vet 180]

how did you go in the end? source the problem?

[matt b]

how did you go in the end? source the problem?

Hi mate
I have ordered some adjustable cam gears and new engine mounts (found one was stuffed while pulling car apart). They should arrive next week so I plan to bolt it all back together next weekend.
I will update the thread then.
Matt

[Dr Danger]

Updates?

[matt b]

Updates?

The car is still in bits as my adjustable cam gears and CAS mount have not turned up. Latest update is they will be here this week......

Once the car is back together I will update the thread.