Twm injection idle issue

Hello,

I have spent about 9 months sorting out my car and it was running
excellent until yesterday.

I have a CAV GT 40 with a 351 stroked to 427/ RBT ZF and
Twm Injection with the Accel gen 7 system.

All of a sudden the idle has jumped from 900 to 1500- 2000 rpm and wil not come down. I checked for any linkage issues but found none. All
butterflys appear to be closed.
The two throttle bodies on the front of engine on passenger side are sucking more air after checking with my sychrometer, This is strange because the butterflys are closed and the air bleeds are also at the bottom.

I checked for vacum leaks but did not find any.

Could ar be coming from around the butterfly shafts or am I missing something.?

If I did not know better it feels like my old 73 911 when the webers
had a similar issue and needed to be rebushed.

When I removed the throttle positioning center the idle even increased to 2500 rpm when started with no touch of the pedal.

These is a little slop in the throttle shaft.

Any help would be appreciated.

Thank You, Eric

Eric,
I too have had some issues with my setup. The issues I had were with the exhaust temps. I found that the entire right side of the engine would not heat up. It was basicly a butterfly issue. Check the allen head screws for tightness. The linkage from the center ring is a bitch to equal out and get even. If you are using a vacum synchronize, then you should be able to get the butterflys even. I used a very thin gauge wire down the throttle body and into the butterfly valve in such a way that the drag on the wire was the same. Sort of like setting the gap on a points distributor.
Set the primary bodies first. Then set the secondary throttles with the second throttle position set screw. When you get them even, on fire up the engine should be around 2000-2500 rpm. Use the primary idle screw to work it down. Usually a quarter of a turn on each side at a time. If you think or know the butterflys are even, then look to the TPS sensor. You may have a loose wire or dirt in the unit. Which electronics are you using? Have you looked at the vacuum tubes to make sure one hasn't come loose or the distribution box has become dislodged? Check all of the sensors. Any or all of these things can lead to erratic idle.
Hope this helps.

Bill