Rev to 5,000?

Have you considered the alternator is bad? The warning light is provided to impart this imformation.

The fact the light goes out at 5000 rpm only indicates one of the three diodes is providing current. The singular diode is lonely for it's brethren and must be put out of its misery. Now.

 

5000RPM is to high, usually you just tap the accelerator and let the RPM go high enough for the Charge light to go off, usually around 2K RPM.

 

Agreed, mine goes off around 1500 rpm

 

LOL!

That's funny.....welcome!

Actually, while 5K is certainly too high, a carbed car wants to fire up and feather the throttle to force oil pressure up as QUICKLY as possible to avoid bearing damage, then, the Owner's Manual does indeed recommend a warm up idle of 3,000RPM.

Then as you hold that throttle position and the engine builds heat and lubrication it'll naturally all by itself climb up to a steady 4,000 RPM.

That's where the 'whoomp, whoomp" of Ferrari racing machines comes from, but they get rebuilt after every event! They are seeking oil pressure.

On a street car, dont go crazy, but mine needs 2,000RPM to clear the plugs from fuel fouling, then warms with procedure above.

After the temp gauge comes up off the pegs and climbs, it will idle down into the 800 - 1,200RPM range. Not exactly idling for a 5.7L Chevy but that how our cars act.

 

The other thing to realize, please, is the function of that red indicator light.

It's not a alternator "charging" indicator when on/off, it monitors an over/undervoltage RELAY.

So it's actually going on or off precisely (+/- Italian factor) at 13V of the entire electrical system.

I'd put a healthy battery in first, because it's easier, but the others are correct it may be the alternator (or it's internal regulator/diode bridge) playing out.

Nothing lasts forever!

Take that alternator in for rebuilding, and I'm always honest about what it fits, as if there are special bearings in there they need to be replaced with same.

8,000RPM at the engine spins the ^&%*% out of the unit! It's a Bosch, but a rare catalog number.

 

I have found that this Bosch unit kicks in at 1000-1100 RPM on my car. That's when the red light goes out. I also have a volt meter in the system and it is at battery voltage until I hit the 1000 RPM range. It then goes to 13.8V and pretty much stays there. I usually only let it run at 1500 when in cold warm up. Usually just need to feather the throttle for a few minutes then it settles into a 1000RPM idle. I had my unit rebuilt 9 years ago and pumped up to 85amps. I did see a conversion some place where someone put in a GM 100amp alternator. Didn't look like a complicated conversion. Considering the NASCAR guys run at 9000 RPM I don't think the revs are a problem. Also the GM units put out 14.2V at a lower RPM. As to your 5000RPM , this to me is to high and needs to be tested.

 

My car idles real nice about 600-700 RPM.

A functioning alternator needs to run at 2000-2200 alternator RPM to put out meaningful current, so depending on your alternator/crank pulley ratio, about 700 motor RPM for charging. An alternator is not linear like a generator is, the alt can put out close to full current at 2500 alternator RPM, IIRC.

Doug

 

Bad idea to rev that high with the engine cold.

 

Hope you get this fixed soon.....then post some pics! And welcome!

 

I just have to rev mine to about 2k and the light goes out...no problem then.


PDG

 

The early users manuals for US cars state to start the car and immediately bring revs to between 4-5k. I am positive this is a statement Ferrari had to place in the manuals for emissions reasons. Otherwise all the other posters are dead right at it being no more than 2k to get the light out. I usually hold my engine at 2500 for the first 2 minutes to get the thing warmed up a bit anyway.

 

Revving before EVERYTHING is warmed up, is not only bad for the engine, but it can (and may even) be worse for the gearbox.

In the 308 gearbox, everything moves - even in neutral. So beware.

Even if the engine is warm, the gearbox may not be, and you can still to great harm by revving up too high, too soon.

Re-gearing is expensive.

 

I miss the manual choke in my 330 2+2. Need it, use it.

btw, the light in my 308 goes out at about 2K.

 

+1

 

very common thing to do