charging system problem

[vashy]

If you saw 16.7 volts then Paul is right, your regulator on that alternator was faulty.

If you saw a low resistance across the terminals, with the battery disconnected, I suspect you have a short as well. What reading did you get? Try connecting an ammeter between one battery terminal and it's connector. Or, the poor man's ammeter, do you get big sparks when you connect the battery? also, measure battery voltage disconnected, then connect it, measure voltage again.

[nosfera2]

Thanks for everyones help so far. The alternator is replaced and a week with an auto electrician has revealed a ecu wiring fault tripping something at about 4500 rpm.

So that's the good news, bad news is it still runs like crap. Really low on power particularly at low revs, also sounds rough as hell, putt putt putting along.

I'm thinking intake leak or ignition problem, exhaust could cause the sound, but I wouldn't expect the power loss?

[JMR_AW11]

Can you confirm: Have you ever seen it rev correctly and with decent power delivery?

Either before you fixed the alternator or after?
Are you sure you fitted a good replacement alternator?

Is it showing any ECU error codes on the dash when you put it in
service/diagnostic mode?

What 89661-xxxxx ECU number does it have? Is it the right ECU for the engine and loom?

Does it have the correct MAP sensor for the 20V (I assume 20V are MAP sensor)

Does this engine run an o2 sensor and knock sensor?

I don't know anything about 20V engines so sorry if these questions seem silly

[nosfera2]

Hi there, answers to your questions:

Yes, when I first bought it, it was OK

Before the new alternator

I hope so

No

I would have to check the number but they were purchased as a package from the same car (i have seen the receipt)

AFM and also part of the package

Yes, the O2 sensor is a possibility but I don't think the ECU uses it under full throttle anyway. Not sure about a knock sensor, will take a look.

[JMR_AW11]

Thanks for the clarifications

I did some googling on the 20V unit and it says it has individual throttle bodies.

Therefore, if you have the AFM version, how are you getting the 1 into 4 air ducting from the AFM? Is this a custom jobbie for the AW11 (home made?) Could this be leaking somewhere?

Does the voltage meter on the dash behave itself during the rough running?
This might help rule out any remaining alternator/battery worries.

[nosfera2]

Hi mate,

You're quite right, it has ITBs but the original intake plenum is retained with the install i.e. it is still as per levin stock (it fits where the tvis would be). Leaks are possible but no more so than any other intake system.

No problems with voltage any more, this is now stable.


Cheers anyway