Idling not stable... Testarossa.

What engine family is your TR? (it's marked above cyl #6 -- it will be something like F113A, F113B, F113A040, etc.)

 

If 91TR doesn't have an answere for you, you are in trouble. They don't get any better than him.

 

Almost unfortunately, your F113A engine (K-Jet without Lambda) doesn't have the electrics of the KE-Jet so it can't be the problem that causes an unsteady idle on the KE-Jet with Lambda TR (throttle microswitch not closing at idle). About all you can do is try running some injector cleaner and/or retweaking the idle mixtures (if the warm-up regulators check out as OKish when cold and warm).

There are so many tight-fitting clearances in K/KE-Jet systems that they really suffer from disuse -- e.g., if one little piece of fuel varnish gets dislodged and stuck in a critical place, you're toast. Sorry I can't be more helpful. Hopefully, it will clear up with more running (with the cleaner), but I have to say that these kinds of problems are more likely when you're bringing an ex-garage queen back to more regular use as you are.

 

Most likely it just needs servicing and setting up.

UK cars are this spec, and they hunt terribly if not tuned correctly.

Both banks must have identical closed throttle butterfly gaps of 0.003".

Clean throttle bodies, correct cam timing and good ignition leads/caps etc etc.

Perfectly synchronise the throttle when actuated by the cable (don't press the linkage with your hand, this takes up joint slack from the wrong direction)

Set idle speed to be 1100 rpm +- 50 using the (cleaned) idle bypass screws near the butterfly. Use a vacuum gauge to read both banks to pull near identical vacuum. Dont trust the cars rev counter for this.

Tune K-Jet mixtures to be 0.7% CO +- 0.1 using good quality recently calibrated and serviced gas analyser.

Note... the fans kick in and out confusing idle vacuum/mixture/rpm, and on a std car, the exhaust swaps side.. LH exit = RH bank etc

See how you go with that, and let us know.

 

As in hunting around I presume. I would check all the Steve has stated, and also add to check the vacuum balance for the engine. They should be with close in HG of each other, to be acceptable.

Does the car drop below 1000 rpm when comming to a stop? As in,clutch depressed and using the brake? Drops to say 400rpm..then shoots back up above 1000, then finaly settles?

 

Perhaps it's just a loose A/C compressor belt.