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If Your're Familliar With The Rbs, Confirm Or Deny.

sonicz

By sonicz,
in Engines & Forced Induction

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sonicz Rising Star

sonicz

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Ok here is an update to the matter in case its useful to anyone.

I went to another sau member place (500hp) and after some testing he isolated the likely culprit is the AIR flow meter. With the air flow meter unplugged, the car held 15 btdc timing fine. Unplugging the other sensor, TPS, aac vavle, etc did nothing to to affect the irrational timing. Plug the AFM back in, car shuts of, upon restart the timing is jumping around again.

So I will try get another AFM and see if that fixes the issue. Hopefully it fixes the 02 sensor being all over the place too.

It's not the cam gear that is worn out, the cas doesn't connect to the cam gear at all. It passes straight through the middle of it and into the camshaft. It's possibly the drive in the camshaft that is flogged out, not anything to do with the cam gear. Can happen when people don't fit the CAS properly, eg. not putting the spacers in between the CAS and the mount, causing the CAS to sit further in than it should and damaging things.

Ok I understand exactly what you mean now. I had a look at the drive on both camshaft and cas end and they a are both fine. A half moon piece of metal shaking hands with the opposite other.

Ok , why do you think you actually have a problem? The ecu alters the timing to maintain idle. Unplug the tps and see what happens. Thats what you have to do when timing the car. How did you set tge base timing when you swapped the cas?

I think I have a problem because the timing should not be jumping around like crazy at idle. I have tested other cars and they hold steady timing fine at idle and above. Unplugging the TPS doesn't change it. I am now definitely satisfied mine is abnormal.

Your best off giving it to someone to look at for you who knows what causes the issues your having.

30mins and the problem should be located.
5mins pulling the CAS out and physically looking at the drive peg
15mins putting a scope on the two signal wires
5 mins checking the shielding
And 5 mins of fart arsing around tidying up.

It might take more than 30mins to fix the problem but locating it is not hard.

I've got several Sensors at the workshop your welcome to try them but chances are it won't be the problem.

I really appreciate that. I just managed to try another members cas and it was still jumping around, but in his car minutes ago the same cas wasn't. So yes you are correct it isnt the cas. As above it seems the AFM is the culprit.

Edited by sonicz
STATUS Grand Master

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Posted
Posted

use datascan to set base idle, if it still does it while its in the "set mode" its abnormal....

i see that timing fluctuation on a daily basis at idle... not abnormal just a few things new adjusting.

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