Vomiter

[richardthestag]

Hi All

400 mile round trip went very well this weekend.

Only grip aside from the fuel costs are that on way home I noticed that the voltmeter was reading in the red sector i.e. >15v

hmm

then 5 mins later was back at 13.something

then 2 mins later was back up at >15v

Only seem to happen when running at around 3000rpm

Once I hit the a roads and was running between 2 and 2.5k it didnt happene again.

Of cource when I pulled over to check the revs drop and the output across the battery terminals was fine.

Tried to rev but couldnt reproduce the fault.

Anyone had an issue like this? Dont fancy an exploding battery

Gauge or Alternator? what are the opinions

Cheers

[flying farmer]

I once had this problem with a recon alternator from Halfrauds, it went back under warranty. I hadn't noticed for months as I was using the car in Winter with lights, heated rear window etc, but come Summer it was up in the 15 volt range.

Neil

[GDPR]

I would suspect the alternator too....the voltmeter is an unregulated hotwire gauge so wouldn't tend to randomly over read

[jleyton]

Gauge or Alternator - I'd suspect alternator, however on a trip to Belgium a couple of years ago I'd only just got to France when I noticed my voltmeter right up at the top of the gauge (15v+). Checked it that evening and it WAS overcharging the battery to the extent that the battery was beginning to emit some battery acid from the, unsealed, caps

Despite my fairly exhaustive spares (see recent post ) one thing I didn't have was another alternator and so I just had to carry on. I covered another 700 - 800 miles and all I could do was to mop up the ejected battery acid and top up the battery until I got home. Investigation confirmed that the inbuilt regulator (Mk2) was playing up on my 18 month old alternator and swapping it sorted the problem out.

The point is though that the battery continued to operate perfectly well for several thousand miles after this incident, even though it was a fairly cheap unit bought in an emergency from a tyre shop. Even then, it didn't fail but I swapped it to be on the safe side and it continues to serve as my back up 12v supply in my garage. So, based solely on my experience, you may not need to worry too much about the battery exploding.

Cheers

Julian

[Kevin Garrod]

I can't explain why your Vomiter is throwing up these strange readings.

I'll get me coat

[malc4d]

I too would be a bit sick if it was mine.....

[richardthestag]

Cheers chaps, just ordering a new alternator.

Also found that my car runs a lot better on shell v powa. Didnt spare any horses on the drive down on Saturday morning and still managed 25mpg. Roads were a lot busier yesterday on the way home so I am certain I improved upon 25

[DJT]

What was the show like?

[HersnotHis]

Cheers chaps, just ordering a new alternator.

Also found that my car runs a lot better on shell v powa. Didnt spare any horses on the drive down on Saturday morning and still managed 25mpg. Roads were a lot busier yesterday on the way home so I am certain I improved upon 25

I only use Shell V power or Tesco Momentum 99 as they are AFAIK the only 99 octane Super Unleaded fuels, the others are 97. Furthermore they are I believe Ethanol free. Due to clubcard fuelsave I get Momentum 99 usually for 5-10p less per litre than the pump price.

The manual states 97 octane however with a relatively high compression ratio the Stag does seem to respond to the higher octane fuel.

H

[jleyton]

Cheers chaps, just ordering a new alternator.

Hi Richard,

I don't know if you've ordered your new alternator yet but you probably don't need one

If it was overcharging then it will almost definitely be the regulator which can be changed in a couple of minutes at far lower cost.

That was the problem with mine and, despite never having done the job before, I swapped the regulator in just a few minutes.

Cheers

Julian

[V Mad]

I only use Shell V power or Tesco Momentum 99 as they are AFAIK the only 99 octane Super Unleaded fuels, the others are 97. Furthermore they are I believe Ethanol free. Due to clubcard fuelsave I get Momentum 99 usually for 5-10p less per litre than the pump price.

The manual states 97 octane however with a relatively high compression ratio the Stag does seem to respond to the higher octane fuel.

H

It seems that many Mk2 engines have had their domed pistons replaced with flat tops, in which case is the compression ratio still as high? In that case (of lower compression) is their any benefit from paying more for high octane fuel?

Oh, sorry we seem to have strayed from the subject of vomiting.....

[richardthestag]

What was the show like?

The show was great fun. managed to get sunburnt on saturday. didnt bother with sunday because it was raining etc etc

Had a whine about public liability insurance and they were happy so long as I had comp car insurance. I think it is more for static engines and non road legal tractor etc

[richardthestag]

Hi Richard,

I don't know if you've ordered your new alternator yet but you probably don't need one

If it was overcharging then it will almost definitely be the regulator which can be changed in a couple of minutes at far lower cost.

That was the problem with mine and, despite never having done the job before, I swapped the regulator in just a few minutes.

Cheers

Julian

guessed it would be the regulator/diode pack etc etc. didnt realise you could buy it as a part. cheers will further explore that path

[richardthestag]

It seems that many Mk2 engines have had their domed pistons replaced with flat tops, in which case is the compression ratio still as high? In that case (of lower compression) is their any benefit from paying more for high octane fuel?

Oh, sorry we seem to have strayed from the subject of vomiting.....

Flat tops in mine, noticeable difference between v power and lesser shell offering which i used for the journey home.

[V Mad]

Flat tops in mine, noticeable difference between v power and lesser shell offering which i used for the journey home.

Maybe you have well skimmed heads and thin gaskets to compensate?