Adaptives out a tad at idle

[gkronberg]

My 123 are at -7% at idle and 456 is getting up to +30%
Being reasonably new at adjusting the TB’s and in Australia, can I get some suggestions on how to bring them back in line .

Thanks

[nawarne]

Gavin,

First, I'd hook the car up to the diagnostics....They might point you to failure of a sensor....Having said that, you've noted adaptives on 4,5,6 are high, so you have done that/have the facility already (doh!)

You need a syncrometer to measure the throughput/flow through each TB.

I'd do a search on here for the procedure - - and one of the German guys has produced an annotated photo giving the sequence to follow.

Double check the springs on each of the TB's (4,5,6) spindles are fully closing the throttle butterfly...believe they can break.

Nick

[gkronberg]

Thanks Nick
TB's are sitting pretty nicely balanced .... just the adaptives way out ...

[Basil Brush]

If not using gaskets, have you checked for air leaks between the TBs and head?

[gkronberg]

Hi basil, have Doms gaskets on , But he recommends checking if they have been seated and sealed properly as well ... next on my list of things to do

[Englishman]

Yes, a leak past a gasket (or one of the throttle bearings) is most likely IMHO, meaning the balancing you have done will be well out.

Also agree with checking the little springs on each of the throttle bodies as they do weaken with heat, meaning one or more of throttles may not be fully closed at idle. Easy to check too.

[spitfire4v8]

What's it like with the breather disconnected from the front of the airbox ?

[gkronberg]

Thanks guys
New springs on TB’s

Spitfire .. when you say breather hose on front of air box .. that’s the oil one ?

[spitfire4v8]

the big pipe from the oil tank breather .. take it off and see what happens