Microtech + quads wont idle?

[WHITCHY]

I just put some quads and a microtech onto my 4age, and it sounds hot and goes well, but it just wont idle at all?
the setup came off a 4age so it is already tuned.
Can anyone tell me where to start looking for the problem?
It is an LT8 with a hand controller.
Thanks heaps for any help with this.
Cheers.
-Whitchy-

[Nim]

Do you know what other mods the engine they came off had? Are you guys running the same cams? What about extractors and the like, all the same?

[ViPeR_NiPPleX]

nice

are you using standard sensors? if so id be checking your TPS idle switch. hows it drive otherwise?

[ivan]

Get it retuned. No matter what its a different engine so you best bet is to retune it. Also you are using different extractors so that will affect the end result too.

Regards,
Ivan

[Joshstix]

You can't expect to move a microtech from one engine to another without needing some fine tuning, whether the engines ar the "same" or not. Small things can lead to big changes in tune, things like compression ratio and cam timing spring to mind for your situation.

[Mr DOHC]

but it should at least idle right???

[Nim]

It's probably trying to, but providing the wrong mixture and stalling.

[chris_rg]

whats your MAP signal like?... I've heard that the MAP signal can be pretty unstable at idle with quads. I've also heard that putting a restriction in the map line can help, some of the megasquirt guys use those cheap carby fuel filters as a damper. To test the theory you could probably just kink the map vacuum line genty to create a restriction and see if that helps.

Otherwise... like others said, tune it!... at least have a play with idle mixtures.

cheers
Chris

[sideshow]

if might be tuned for map

if its N/A then get it tuned for tps

[CrUZida]

If its properly setup it should be tuned in TPS for IDL, and tuned in MAP for everything else.

Check to make sure your Quads aren't 100% closed at idle, you may have to crack them open a little bit.

[WHITCHY]

shit thanks for all the replies!
The engine it came off was stock with custom extractors,so i wouldnt think there would be much difference, but i guess there is!
the map signal is sweet, the adapter plate has a cylinder welded under it connected to all 4 inlets, and that is used for vaccum for the brake booster, the vaccum signal for the fuel pressure reg. and to the vaccum line for the ecu.
it drives fine, I had to put a new dizzy in so the timing was farked and it was pinging like hell, but now the timing is sweet and it still doesn't idle any better!
I am gonna fiddle with some more things tomorrow and go and get it all checked out by the guy i bought it off. So hopefully it will all be sweet by tomorrow arvo!
If anyone has any more suggestions tho keep em coming!
Thanks heaps for all the help so far!
Cheers.
-Whitchy-

[TurboRA28]

Post some pics man

[Darren]

Just to reiterate, get it tuned properly!

Do the quads have some form of idle adjustment screw or adjustable throttle stop? It could be as simple as bumping up the idle speed.

I run a microwreck on my 4ag with quads and massive cams, from dead cold you can hit the start button and it fires and idles with zero throttle input. It sounds like a rotor but it idles.

Darren.

[ivan]

I run a microwreck

HAHAHA

tooo true...

Ivan

[Starfire]

Dont forget that even if the engines are the same (same condition and the like) if the readings from any of the sensors are off then it can make a pretty big difference to the overall running of the engine.

A bit of dyno time is well worth the investment, especially when you consider the difference it can make in both performance and economy.