Whats Causing this - Or is it normal

[Rom]

So i cant remember what my idle was like before the rbc.

But since ive fitted the rbc, it has been hunting between 1k - 2k when warm. And idling a bit high mostly.
I had cleaned the ICV, to no avail. So was thinking this was at fault.

Ive since found the thermal gasket wasnt sealing properly. So there was a slight air leak on the top corner nearest TB. This is no fixed, the hunting appears to have stopped. The revs no longer change when spraying lube around the leak, which is how i found it.

But it still seems to idle slightly off. Heres a video to show it.

First i blip it, then hold it for a second, then turn steering, then last bit is a blip again.

[media]https://www.youtube.com/watch?v=FHzAShF7ASo&list=UUfy_2AqsI-Ex9PfLsARn9NQ[/media]

It seems to hang a bit before it settles down to normal idle. Also seems to climb slightly after letting off.

Is this how they all are ? I cant remember

If not, whats the likely culprit ? ICV ? IAAV ? Is it worth picking up a used ICV to try ?

Thank you, as always.

 

[Alexander0628]

Mine was like this but after cleaning up the IACV it was better not perfect but better. Since you fitted your intake and gaskets ect have you taken it for a good blast, and I mean giving it the beans, this worked for me to.

 

[Rom]

Yeah I have mate. Got a thrashing at the weekend.
Reset the ecu too.

Not sure if it's worth trying another icv or not

 

[Alexander0628]

I see, maybe this could be because of the different intake and the fact it's not been mapped, I'm sure someone who's had an rbc fitted will answer that.

In the end I fitted a new js racing tb and it's been perfect ever since but mine got as bad as bouncing revs as I was driving down the road. Looks like tb problem from what I have read in other threads.

 

[Erm]

slightly off topic, but engine management light is on?

 

[Rom]

Yeah decat mate. Kpro is in the near future.

 

[Erm]

Yeah decat mate. Kpro is in the near future.

ah ok! As you were on this thread

 

[Linus27]

Mine is exactly the same.

 

[davidpingu]

Looks classic iacv issue to me. If a good blast doesn't solve it and cleaning hasn't helped there isn't much else you can do other than think about a replacement. See if someone is willing to swap theirs with you for a couple days just to confirm perhaps?

 

[Rom]

Ive got a used one coming. So ill try that. My only problem, is if it still does it, i dont know if the new valve is duff, of theres a different fault

 

[davidpingu]

That would be unlucky. Completely strip and clean the new one before it goes in. They don't like damp of any sort. I take it you've been fully stripping it including removal of the odd shaped bolts. Tiny blast of wd40 or similar seems to help keep it loose. Good luck!

 

[Rom]

Yeah, the first time i didnt remove them. Idle was bad, so did it again, removing those bolts.

Doesnt matter what position the valve is in does it when it goes back together ? It didnt seem to locate into the electronic side any particular way.

If i did get it wet, it would of had to have leaked in from valve end, past the bearing. So can imagine much got in there, i only sprayed it, not like i submerged it.

The icv is a simple swap, so ill try that when it arrives. Bit worried about cleaning it, in case me cleaning it is what killed the current one.

 

[davidpingu]

Stick to using brake cleaner or an alchohol based cleaner to be sure it leaves no residue or rust. That's all I did was give it a good blast of brake cleaner, leave it soak then keep working it back and forth. Mine was very sticky. Dried it with kitchen towel and then a light spray of ptfe based stuff, nothing too heavy.

Fairly sure it will only go back together one way so if it screwed back together you got it right

 

[Rom]

Yeah it was brake cleaner I used. Then a bit of lube after.

Ill have another look tonight, let it warm up, make sure it doesn't hunt.
Then try the icv when it arrives I guess

 

[RunsWithScissors]

I cleaned mine with petrol. It evaporates after use and gets rid if all the crap. Then a tiny squirt of WD and you are away.


Sent from my iPhone using Tapatalk

 

[Rom]

As an update to this.

It's currently idling fine.

I'm still waiting for this other icv to show up. So I've not done anything to the car.
It's also hardly done any miles.

The day it started, it drove around to 100 miles. So I'd have thought that would have cured anything it was going to.

So as it is, it's no longer hunting, idle doesn't hang quite so much. And idle is anywhere from 800-1000.

So even when this icv shows up, I won't be fitting it. I'm not messing with it again until it plays up!

 

[Phelpo711]

Surely if you had a decat and an RBC fitted the Ecu will have no idea what's happening where the cat used to be I.e, what's going on regarding fueling/ air ratios?

I know sometimes if you reset an Ecu they do idle higher for a bit while it figures out the best ratios?

Either way if it's okay now maybe it's figured it out, but you will have to get a k100 - koto done after those mods!

What manifold did you go for?

 

[Rom]

The fuel air ratio is read by the primary o2 sensor. This is still fitted. So they ecu is still getting as a precise reading as it ever did.
The secondary o2 reads the same, but after the cat. Basically telling the ecu the change between 1 and 2. Thus telling the ecu the cat is working (because the afr should be different between the 2)
This is why a decat throws the eml on. Because sensor 1 and 2 are reading the same afr, so ecu thinks cat isn't working.

For optimal gains, your quite right. It needs mapping to really make the most of the mods. The standard ecu will try it's best, but it's only aiming for standard afr, timing etc.

I've still not hooked it up to the gas analyser, so I don't know what lambda, co etc it's running. But it still popping on shifts and off throttle. So it must have unburnt fuel going through it.

I've got a Buddyclub header, and system. Rbc, and mugen intake.

 

[Phelpo711]

Ah fair enough! What are the views on the buddy club header?

I'm looking in the very near future of getting an RBC/RRC and hopefully a toda mani but obviously they are ridiculously priced!

 

[Rom]

From my research, the rrc doesn't appear worth pretty much double the price. Unless your going engine rebuild etc. The gains over the rbc are negligible.

The buddyclub header is nice. I'm on spoon springs and scrape it a bit.
But that's common on a lot of headers / b pipes.
Didn't make a massive difference in sound when I had a twin loop on, but the baffles are huge on those!