Anatomy of a 348 (Denso) Starter/AC Generator

Those of us with slow dial-up connections can't wait for all those pictures to come up.

Have you tried jump starting the car? Does it crank over faster? That might indicate a battery with weak cranking capacity.

The Denso starter may have a housing that's unique to Ferrari, but the internals are the same as many other cars. There's a contact set inside that can get horribly dirty, and can be replaced at reasonable cost by an experienced auto electrical shop. That might help.

There's also a possibility that the bullet connectors in the cables are dirty or loose.

 

Just to clarify: when you say it's "turning over slow", do you mean that the starter IS actually turning the engine at a speed that is slower than normal, or do you mean that the starter is NOT turing over the engine on some occasions and you just get a "click" when you turn the key?

 

This picture of yours shows the typical dirty contacts inside the starter - make sure these are cleaned up, and the ring on the plunger. Might help.

I would also suggest that once you have your voltmeter available, check the voltage at the signal wire from the ignition switch - the one that plugs into the solenoid next to the battery cable. You have to have someone turn the key to the start position while you read the meter. If you get a reading that is less than full battery voltage, you need to install the relay system in order to get proper operation of your starter.

Also, check where your negative battery cable attaches to the subframe, make sure the terminal is clean and tight.
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Follow Miltonian's lead.

 

Nice pictures!!!

I would start by check ALL of your ground attachments.

 

Must have been a 24 hour glitch!

 

I had the same exact problem and it drove me nuts but I had the starter rebuilt and never had the issue again.

 

The starter contacts are a constant sorce of problems with these starters. The plunger also creates issues. The reason is the current when the solinoid is energized burns the contacts. The input side contact provides the current, then is transfered via the copper ring on the solinoid to the output side of the soilinoid. So as you can see by the photos the burnt contacts.

These contacts and the solinoid plunger are avalible at any starter rebuild shop. The contacts wholesale for $1.00 each, and the plunger runs about $5.00. The most important part of contact replacement is making sure the contacts are equally parrollel so that when the plunger engages it make complete contact on all surfaces of the contacts. This will pay dividends for longevity and full voltage accross the soilinoid. After we install the new contacts we use "blueing" and install the plunger and check for total contact, then clean off the blueing and assemble the starter.

This is the same starter design used on many Japanese cars, and is a very trouble free style with the exception of those damn starter contacts. The classic symtoms are just a click when turning the key. usually you can turn the key and hold it in the start position a few times and the starter will engage. Sometimes if you just click it a couple of times, then hold the key in the start position, it mysteriously engages and starts. We change out starter contacts and plungers several times a week in our Subaru Service Centers, a really easy DIY process.

Howard Musolf
1981 308gtsi
1982 400i Cabriolet
1994 348 spider
1988 Lotus Esprit Turbo
2006 Mercedes slk280

 

the problem is in the key wire, put one relay in terminal 50 and the problem is absolute solved