3.4 Carrera running lean on one side?

[cgarr]

This is my 3.4 Carrera, twinplugged etc. engine. I have Bens mutant muffler on it with B&B headers and each side is seperate so I can check left and right sides AFR's

At idle I set the left side to 14.5 and the right side is 13.2 and if I set the right side correct at 14.5 then the left side is 15.9

I have been thru everything on this damn engine as far as air leaks BUT if I spray some brake clean around the back of the throttle body (which I removed and sealed) the AFR's will drop to around 13 so it is picking up the brake clean from somewhere? But where? I really don't get a change spraying around the intake to heads seals so I assume they are not the leak. With the spray is does smooth out the idle as it starts go go rich. Right now I have it set correct on the lean side but that makes the right side rich at idle. And Injectors were all cleaned and serviced.

Any Ideas? What did I miss? Where should I look or try?

Thanks

[CruiseControl]

Craig
Assume that you are running ITBs
I had a similar issue, which was more noticed when coming off throttle. Although the initial balancing of L and R sides was OK with air flow balancing meters. At idle a difference of about 0.10 Lambda and off throttle (pulling vacuum) the difference between L/R AFR was much greater.
Anything above closed throttle the AFR of both sides was OK. Could find no air leaks to the manifolds, ITBs

Minor adjustment of the L/R throttle linkage and idle stop screws has rectified the differences at idle and off throttle. When I say minor a 1/8 turn of the L/R balancing links (the ones with the left and right hand threads) would make a noticed difference.

Paul

[cgarr]

Well I may have found the problem, if I spray right on the large boot that connects the 2 manifold halves the engine will surge up and down then quit. I loosened up the boot and rotated it without luck, it looks to be a lot larger than it needs to be so a new one may be in order.