Hunting Idle (did a search!)

[stylus350]

Hi. Any help on this?

The turbo and manifold were off today to have a crack in the manifold welded. (single turbo). all put back together and started, allowed to warm up and all is ok. Took it from the garage and about 10mins into the drive home the idle was hunting between 1200 and 1800 rpm. Also when I change gear the revs seem to rise 2 to 300 rpm momentarily between changes.

I have checked the vacume pipes, there are not that many realy. I took the small pipe off the back of boost pipe that comes from the turbo and blew down it immediately finding a split where one vac goes into one side of the Greddy boost control valve. Took it off, cut it back and re attached. Blew down it again and no more leaks there. The two coming off the inlet seem fine too. Started it up thinking it was sorted but its not.

Where else to look? Are there any \'tricks\' to finding a leak? I think I read spraying water might help to locate one. I can\'t blow down the boost pipes!!
I suppose it could be an inlet gasket?

Any ideas for eliminating other potential causes?

[stylus350]

Just read the last post on this thread - so here\'s hoping it sorts itself out in the morning!

http://www.mazdarotaryclub.com/forums/showthread.php?t=26333&highlight=hunting+idle

[nikp]

I been having idle problems on mine - basically have been finding it very hard to get the idle stabilized to 1100 (It\'s street ported). But after a very long time, it\'s getting there, and i run an Apexi too. I\'m finding it\'s not just a couple of hours or whatever, it seems to be days for it to stabilize!

[stylus350]

Seems to have sorted itself out today. I called Pip this morning and he told me how to play with the fuel setting thingys in the rpm seting blah on the apexi so they are not too close to the idle. I could actually adjust the amount the revs hunted. Once I got it settled i just sat there for a while, then turned the heater on full etc. same as if I was first plugging the Apexi in and its damn close to being a solid idle again. I expected it to go straight back once Id found the air leak but thats not the case. Happy again

[yehreally]

stylus350, if you wanted to share the info on \'the apexi fuel settings thingy in the rpm setting\' would appreciate as having similar problemo\'s...many thanks

[stylus350]

stylus350, if you wanted to share the info on \'the apexi fuel settings thingy in the rpm setting\' would appreciate as having similar problemo\'s...many thanks

From memory (cant be arsed to go outside again its too cold!). Go to settings and then to rpm which is last on the screen as you scroll down and go into that screen.  At the top is the rev limiter (handy if your leaving your car anywhere to have work done and you suspect they may go out for a \'raz\')and you will see FCA, FCB, FCC. Under those will be the idle set. Make sure the fca etc. settings are at least 250 rpm higher than the idle set or the car can hunt between the two. I played around with them for a bit and could see the hunting  change as I played with them. Hope it helps, but I think there are a few different reasons for hunting. I will go through it again in the morning when im on my way out but thats prety much it.

[yehreally]

Very useful - Have a happy Xmas :Santa