R33 Rb25det Hunting Noise, Timing Is Fluctuating On Idle....

[deva0o]

Hey SAU,

I have a r33 gtst manual which I've owned for about a year now. The car has had a weird hunting/idle issue since I've had it. I've plugged my ecutalk in to have a look and from what I can see the timing jumps up and down. I tried blipping the throttle a few times lightly and sometimes It would sit at 15 degrees at idle when it came back down from the revs with no dipping and hunting noise. When its fluctuating it can fluctuate from what I could see around 5 degrees to about 13. It does this a lot, no matter what the temperature is like or how long I've been driving for. It can sit normally at idle and be fine and then a few seconds later it will fluctuate and you can definitely hear it without needing to plug in any consult software.

I've always felt like the car just doesn't perform like it should. Feels weaker than most rb25s I've driven. Not sure what other info to post up but the only other reading from ecutalk that was being erratic was my O2 sensor voltage. Which at idle (Can be at 15 degrees or when its being erratic) will go up close to 1 voltage and then drop back down and then up again etc etc. This may be normal but I'm not to sure?

People have said to get another CAS and to get the timing reset. I was just wondering what the forum thought and what other things I could check out or any other info I can try post up from ECUtalk etc.

[R31 POWER]

A mate was having the same problem, it turned out being this lol.

[wolverine]

Hunting at idle...more often than not is a simple intake leak.

Time to go around the car and wave a screwdriver over all hoses and clamps and inspect all the vacuum hoses.

[Ben C34]

Timing fluctuations at idle are normal as the ecu uses timing along with the IAC valve to control the rpm.

Check for vacuum leaks and set the idle screw in the aac or IAC or whatever its called on a 33.

That broken cas mount is nuts!

[deva0o]

I remember getting a smoke test done on the car to find a leak a while ago, and any leak that was found was fixed. The problem is still there since then.

The car seems to idle around 650-700ish when warm so I think the idle is correct.

[KiwiRS4T]

If you have access to a timing light and can borrow a known good CAS you can quickly eliminate that as a problem (or not).

Or there is a tutorial on here on how to clean your IAC valve.

[wolverine]

No harm in raising the idle a bit to 900rpm o settle the timing fluctuation but I would still check every vacuum hose for a splits and check intercooler hoses.

[AngryRB]

I broke 2 cas's by somehow not aligning them properly, don't ask how, but both times they idled weirdly and one time it went jerky and stalled and later found the shaft had broke off,

so be careful, I actually bit scared to put that cover on anymore incase the shaft doesn't align straight , cant remember but theres some spacers or something involved...

[deva0o]

Thanks for the replies so far everyone. I will have another look for any leaks and get around to cleaning the IAC this week then. I guess after that I will move onto finding someone to check the timing and maybe getting my hands on another cas for cheap to test.