Ferrari Mailing List: Re: Testarossa repairs

[Richard Lindsay (richardolindsay]

Agreed, Stephen. Yours must be a US Spec K-Jetronic car. The high idle
is a cat converter heating step. It is normal.

On Tue, Jan 27, 2015 at 7:55 AM, Stephen Sherman
<stephensherman44 [at] gmail.com> wrote:
> Add some pictures.
> Rick my 81 308 starts idles at 1000, then 3000, then back to 1000 after it
> warms up, I have been told that is normal.
>
> Stephen
>
> On Tue, Jan 27, 2015 at 6:57 AM, Rick Lindsay <richardolindsay [at] gmail.com>
> wrote:
>>
>> Hello Friends,
>>
>> Quick update this morning: My-Ric's-Deep's-Ric's-etc's Testarossa is back
>> running. You may remember this car and the fact that it has always had idle
>> problems - and starter problems. The later is probably just excessive wear
>> from restarting after stalls. Anyway, I bought this car ages ago with the
>> upper half of the engine in cardboard boxes. After careful reassembly and
>> retrofitting the K-Jetronic fuel injection, the car ran great...but it still
>> suffered idle instability. Charles Perry also has an early Testarossa with
>> precisely the same malady. Design problem?
>>
>> While studying the workshop manual, I found no mention of idle problems.
>> However, in the parts manual I discovered a part that neither my car nor
>> Charles' car has installed. It is a pipe that connects the outputs of the
>> Control Pressure Regulators (also called warmup regulators). This little
>> pipe causes the control pressure - the back-pressure applied to the mixture
>> regulating barrels in the fuel distributors - to be the same. Otherwise, the
>> two fuel injections, one per bank, compete for control of the engine. Our
>> cars don't have that pipe installed so any tiny imbalance in the induction
>> triggers the competition. The end result is oscillations in idle speed. In
>> fact, the problem is so severe that the engine often dies. That's
>> inconvenient,  embarrassing and dangerous when it happens in traffic -
>> especially when a wonky starter acts up! Just ask Matt Boyd!
>>
>> So the answer to the malidy is to add the balance pipe and retune the
>> induction, both air balance and fuel-air ratio. And that is the task at
>> hand. Oh, and I also have a new starter! I'll have the old one rebuilt
>> locally and keep it in reserve. It also fits my 308GTB and accessibility is
>> becoming increasingly difficult (read: expensive).
>>
>> A day ago I went to my storage facility and began the task of bringing the
>> car home. The first step was to remove the air cleaner assembly. That alone
>> is non-trivial. Once off I could reach the idle speed adjustments. I added a
>> half turn to both banks and started the car. I had previously charged the
>> battery since this wonky starter only engages with a fully topped up
>> battery. The car started easily, as is usual with a K-Jetronic fed engine.
>> From dead cold, it idled smoothly at about 1200rpm. As heat brought the
>> tolerances into spec the idle speed increased to around 1600rpm. That's way
>> too high BUT it was stable. The upstart of this is that I can now drive the
>> car home to affect repairs. I have all the parts (as does Charles) and the
>> instruments and gauges to do the tuning. I only need time and a little nice
>> weather. Fortunately, this week affords both!
>>
>> So this afternoon I'll bring the car home, give it a bath, then begin
>> disassembly, updates, a starter-ectomy, then tuning. Photos and how-to words
>> to follow, Charles.
>>
>> -rick
>> Sent on a Sprint Samsung Galaxy S® 5
>>
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>