Posted: May-15-2008 05:11PM

That's excellent news on both counts.  Remember not to throw out the old Smiths oil pressure gauge.  It's probably (somehow) gotten dirt inside that's jammed the pinion gear.  Easy enough to clean once you remove the bezel and glass.

Thanks for posting an updated and sharing your findings.

Doug L.

Posted: May-15-2008 11:48AM

Hello All - Fuel gauge now working after putting a spare voltage stabilzer in series with the fuel gauge . So thanks for all the info .

Oil pressure problem  - took plugs out - spun the engine with pressure gauge - zero pressure - replaced the gauge - spun the engine and got 75psi - no problem . Result - a bleep duff smiths oil pressure gauge nearly gave me a heart attack. . Thanks again chaps . Regards Bruce

Posted: May-11-2008 06:44PM

Doug L.

Posted: May-11-2008 11:25AM

Also it dropped to zero so the crank bearings can't go that quick unless the pumps breaking up and it was new less than 300 miles ago. Commenst  

Posted: May-11-2008 11:22AM

 Hi Doug - yes I'm using a digital meter - so you have explained the voltage variation from 'I'. Fuel gauge seems to be working  . I'll keep a close eye on it .

BUT . Major problems today while test running the car . Oil pressure dropped to zero . Since a recent rebuild I have had 60 plus oil pressure . I chnaged the gauge to a full 0-100 psi as opposed to 0-25-75-100 version. I noted while at tick over the pressure was good ( 60 ) but when reved to say 2000 it dropped to 50 then when at tick over back to 60 . I checked the levels - - on min so added a pint . Repeat the process then same again - suspect Relief valve stuck ??.

Posted: May-11-2008 08:47AM

Hi Bruce.  It's hard to get a good measurement of the I terminal of the stabilizer.  It's harder still if you're using a digital meter.  If you have an analog meter use it for your measurements.  If the stabilizer is working you should see it's I terminal output blip up and down between 0V and 12V anywhere from MANY times a second... to just a few times a second.  A digital gauge won't capture this switching. 

Remember that the B terminal should have steady 12V on it anytime the ignition is turned on.  Both the fuel and electric temp gauges should have the switched on/of (average 10V) supplied from the stabilizer I terminal.  If you reverse the connections on the stabilizer (12V in on the I) the stabilizer will heat up, open the contacts, and you should get NOTHING (0V) out on the B terminal ever.

Doug L.

Posted: May-11-2008 08:39AM

Hello Doug - checked the fuel gaugeand it reads 12.93 volts supply . The stabiliser on the rear of the mini speed was then coupled in series to the fuel gauge . I Checked the stabilser 'I' terminal volatage to garound and it seems to vary from 0 to 12 volts . I relapced it with another stabilser - same problem . I reversed the terminal connections on the fuel  gauge and it reads about half full with approx 2 gallons in both tanks . I'll do some voltage checks to ground next couple of weeks when I have more time - I'll struggle and keep a fuel can in the boot for a while . Keep you posted . Regards Bruce

Posted: May-07-2008 04:18AM

Bruce,
For more info on the voltage stabilizer and troubleshooting, see my PDF:
http://home.mindspring.com/~purlawson/files/SmithsVoltageStabilizer.pdf

The link Don posted includes pictures of a solid-state replacement for the voltage stabilizer.  I was unaware that our host had started selling these but I knew some other British car vendors carried them.

Remember to post back to this thread after you've done your tests and measurements.

Doug L.

Posted: May-06-2008 11:59PM

Hello Don - this is excellent info . I was not aware of the reasons for the 10volt supply to the gauge but now , with Dougs info and your link , it all makes sence .If I understand correctly the stabliser pack is pwered from the battery supply-nominally 12volts to conection 'B' and the feed to the fuel gauge from 'I' . The second connection from the gauge then goes to the sendor . i.e. the satbiliser is in series with the supply to the fuel gauge .

 I've tried the minicooper register for info and a number of 'so called experts'but none have been so pro active as the minimania site . I'll use it as my first 'port of call' for info in future .

 I'm going to continue with the checks recommmended by Doug but will also keep you both informed . Many thanks for your help. 

A couple of pics and  info about my S . It used to be raced in the 70/80's in Scotland at the Aberdeen Motor club (Colin McRae club) . Its now a 1293 cc with a kent 276 cam , twin down draught dellortos ( ex Fiat Abarth), Stage 3 head, full adjustabel , negative camber all round, sport fuel pump , fuel , brakes and power all inside and manual adjuster for rear brakes  - built for hill climbs - and its noisy !!

Posted: May-06-2008 01:08PM

If you can access the back of the fuel gauge it will be easy enough to check if the stabilizer is wired in and/or active.

Switch on the ignition and place a multimeter lead on the solid light green wire going into the gauge (NOT the green/black wire) and connect the other meter lead to a good earth/ground point.  If you measure 12V then the stabilizer is not in the circuit or is not working. 

Do post back and let us know what you find.

Doug L.

Posted: May-06-2008 09:36AM

Hello Doug -no offense taken - its good to find someone for advice . The smiths suel gauge was purchased second hand from ebay . . The loom was produced by Autosparks based on a Mk1 S loom with modifciations including  bypassing the standard fuel gauge at the back of the mini speedo, also no connections to the volatge stabiliser. The loom provided two connections for the fuel gauge and your correct one goes to the sendor - I've not traced where the other connection  goes but I can talk to autosparks tomorrow and get details .

Based on what you say-  maybe i need to couple up the voltage stabiliser at the back of the speedo and splice in the 52 mm fuel gauge. I did note that when first connected and powered up (the tank was empty   the fuel gauge displayed quarter full- maybe this matches your comments about 10 volts versus 14volts.

 Regards Bruce

Posted: May-06-2008 08:24AM

Do not take offense at my questions below.  I'm not questioning what you know but inquiring about what you've done.  

You said you are using a standard Smiths 52mm gauge.  Is this a new gauge or did you buy it used?  When you connected the fuel gauge, obviously one of its terminals is going off to the sending unit.  Where is the other wire on the gauge connected to?  Specifically, did you remember that Smiths gauges do NOT connect directly to the car's 12V supply but must be connected to the 10V output of the voltage stabilizer?

If you have connected the gauge directly to +12V your readings will be high.  Actually, when you do not use the stabilizer, the gauge sees MORE than +12V, it will see closer to 14V depending on what voltage your alternator operates at.  Consider that 14V is 40% higher than 10V and this in turn can make your gauge read as much as 40% higher.  You can see that connecting the gauge to the stabilizer is very important.

Doug L.

Posted: May-06-2008 05:13AM

other pics

Regards Bruce