TR throttle shaft

While having my FI apart (88 TR), I layed the throttle shaft down (the rod common to both throttle bodies), and noticed that one side was about 1/4 inch different than the other side.

The manual calls for these having to be exactly the same.

I will now re-adjust these on my milling vise, using a dial indicator.

It seems that, because of this, I will have to re-adjust the whole system from scratch.

Jeff: Take note and check yours.

Henry..do you mean the link that connects to the adjustable rod that connects to the throttle butterfly? I'll take a look at mine tomorrow. I brought the whole works into my living room to watch F1 qualifying while I sat there fiddling with it, cleaning stuff, and just studying it in general. It would make an interesting center piece if left on the coffee table.

I believe that is it. It is the "center" rod that the spring is attached to. Turning it opens both throttle valves. They MUST be exact!!!!!!

I can certainly see why you'd want them the same. If they are not, then one side is opening up more than the other. Not the best for performance. The angles must be the same, or the distance traveled will not be the same from one side to the other, even though this may be minimal.

I just noticed that the adjustable linkage, on both sides, is set the same. Hence, the misalignment shaft is NOT compensated for in the system.

I will have to start from scratch........just imagine how well I will know the system after this, and of course the air flow sensor plates!!!!!

Hank,
If you have a moment, read through my thread on BB carb set-up. The issue of verifying off-idle throttle angles is a real concern...and a great insight on your part.

The dual vaccum gauges, that we've discussed in the past will come into play here...when you verify engine vacuum above idle, say at 3000 rpm.

Granted a carbed car is different, but the end result is still very noticeable. Fortunately, I can adjust the linkage arm angles and length to achieve high speed cross-balance "perfection"....

I know you and Jeff will be pleasantly surprised at the driveability/performance improvement upon properly throttle angle adjustments.


Regards,
David

David: The strange thing is that the car ran fine before all this........am I opening up a can of worms?

The previous owner never touched ANY repair issue on the car........had the dealer service everything from when he bought it brand new. I am the second owner. So I can safely assume that no one touched this since the car was new....the safety caps are still on the throttle body screws.

My only explanation is that, over the years, one of the linkage attachments, at the end of the shaft may have moved due to the forced applied by the throttle cable.

Hank,

I'm the wrong guy to ask about opening up a can of worms...as I truly have no fear when it comes to taking things "totally" apart.

Unlike Japanese or German cars for the most part, IMO, Ferraris are not perfect...I know, likely the understatement of the year from me. Your explanation makes sense, and I suspect that your efforts to verify angles and linkage arms will be worth your troubles.

Although I have great confidence in my abilities and memory...I still measure, sketch and photograph before complex dissassembly begins...just so I don't screw things up more than they are already screwed up! Your mileage may vary...

Best of luck!

Regards,
David