Disco 1 v8 - alternator, large pulley vs small pulley (no aircon)

Hi All,

Apologies for my absence of late - we've moved house!

Anyway, I have this wonderous D1 manual v8, which has only had 1 issue so far - the alternator was on the blink. I happened to have a "spare" 2nd hand 100 amp alternator in the garage which came with my donor engine for the v8 defender project (stalled, awaiting barn!).

I swappped the alternators, and then realised the belt didn't fit on my new alternator, as the new one has a larger pulley. I was aware that there were 2 pulley sizes, so I just grabbed a belt that did fit (I have a couple of different types for testing on the defender), and we were away!

2 things have become apparent since then:

1) The revs read much lower now on the rev counter. this makes sense, as the revs are "sent" by the alternator, and whilst the engine revs can't have changed for a given speed, the reading has.

2) There is quite a whiff of petrol outside the vehicle. Would it be fair to say that the ECU might be causing the EFI system to overfuel because the revs are reading wrong?

moving on from this, can anyone help me out with the part numbers for the small pulley alternator, and the large pulley alternator, so I can make sure I order the correct new one?

Thanks

Adam

farmershort said:

2) There is quite a whiff of petrol outside the vehicle. Would it be fair to say that the ECU might be causing the EFI system to overfuel because the revs are reading wrong?

Click to expand...

No, the fuel is pressured in the line and the injectors fire wasted spark with signal from coil.

Thanks for that CT.

Any idea of the part number differences on the pulleys front? I think from memory the electrical bit is covered by A127-100 (100 Amp). Obviously that doesn't define anything about the pulley, so I assume there are 2 different LR numbers.

The fuel smell may well be a problem in the fuel system then... leaky tank.... leaky sender.... that sort of stuff I imagine must be as common on discos.

Disco1 alternator A127-100 are manufactured by Magneti Marrell and are supplied with the pully fitted, there's no alternative unlike the 65, 80 and 85 amp Lucas alternators fitted to early D1s
Maybe different with Defender alternators some thing 4u to check.
A127-100 for the D1 are AMR3107 or AMR2474 depending on vin.

Now back to work.

Sent from my iPad Air on a train.

discool said:

Disco1 alternator A127-100 are manufactured by Magneti Marrell and are supplied with the pully fitted, there's no alternative unlike the 65, 80 and 85 amp Lucas alternators fitted to early D1s
Maybe different with Defender alternators some thing 4u to check.
A127-100 for the D1 are AMR3107 or AMR2474 depending on vin.

Now back to work.

Sent from my iPad Air on a train.

Click to expand...

Cheers Discool.

so it's odd given that my donor engine alternator was from a '94 v8 manual, and my "active" D1 is a '96 v8 manual. I'd expect them to be the same, although perhaps there's a difference with pre-AC vs post-AC? mind you... my active D1 is the later model, and is non-AC.

Thanks for the part numbers, I'll check them out.


EDIT: AMR2474 seems t be a wiper wiring harness.. the 1st part number is the 92-94 alternator though, and a photo on LR direct shows a large pulley. I wonder whether the 95-onwards are then the smaller pulley.

farmershort said:

Cheers Discool.

EDIT: AMR2474 seems t be a wiper wiring harness.. the 1st part number is the 92-94 alternator though, and a photo on LR direct shows a large pulley. I wonder whether the 95-onwards are then the smaller pulley.

Click to expand...

A typo, to many distractions at the time on a train, so AMR 4247 is the number and is the later alternator.