Moss Motors, Ltd

Lou,

If the 20W50 is fresh and clean, stick with it. I would only use the 10W40 as a "rinse" on an engine with mileage on it like yours. This advice is kind of generalized since I don't know the specific history of your machine. Always change the filter with the oil, as you have been doing.

If you intend to run the car in cold weather (it seems like you don't) use 10W40 for that time. Whatever you use, supplement it with a ZDDP additive such as the one Moss sells, or BG Chemicals MOA. These engines need it to live long and healthy lives.

Once you've rebuilt that front end you're really going to say weeeeeeeeeeeeeeee!!!

---

Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon

roger wilco!   I'm starting to enjoy her now - although, was a little tough starting this morning (was in garage all nite) - maybe i should pull on the choke first thing in the mornings THEN try to start her?  she fired right up her just a little bit ago coming home for lunch - I'd say she sat for about 3.75 hours since arriving at work this morning - maybe just have to keep tweaking the idle adjustment - it'll help a LOT once i get the tach replaced - at least then I'll know what rpm i'm idling at....

I'm hoping the suspension part isn't going to be terribly expensive - might be a good next phase once the rains come - i'm hoping it just needs bushings mostly and adjusting -- looks like a few of the "rubber" bushing are quite worn out (almost flat in a two places) -- will take it step by step and let you know how she turns out in that regard....

Thanks again to all of you for the inputs.... for now, just gonna enjoy this little baby!!!  whoohoo!!!

---

Lou
'76 MGB RD
'70 MGB GT

Lou, Concerning your tach, If you have access to a hand held tach, you can try using alligator clips to connect it in parallel with the tach in your dash to isolate the problem. If your hand held works, the tach in your dash is bad.

There is a wire that goes from the negative terminal of your coil to the input of the tach, is that wire (connections) good? You can use an ohm meter to confirm, but first disconnect either side so that you don't read continuity through the coil or tach. It's easiest to just pull the slip-on connector off of the coil.

If you have power and ground at the tach, AND that sending wire is good, then you have a bad tachometer.

---

On their death bed, nobody ever said, "Gee I wish I'd spent more time at work!"

'68 Sprite 1275
'76 Midget 1500

It sounds like Lou's car has a current sensing tach, by his description of "loop of white wire in a weird plastic thing"  on the back. This is in the 12v line from the ignition switch to the coil.

The tach should also have a white wire attached to a single spade terminal (for power) and the case should be well grounded (black circuit) usually by a wire on an eyelet that is fitted under the gauge clamp "thumbscrews"

On my car (an MGB), someone had bypassed the white line from ignition switch to coil with a new wire from the fusebox, so the tach would not work until the proper circuit was restored. I fixed this, and put a new loop of wire in the tach sensor pickup, joined to the main harness by bullet connectors. This allows easy removal of the tach (the pickup clamping system is very fiddly when standing on your head under the dash) AND its easy to disable the car by opening one of the bullets, if desired.

Ed

---

I want my MGB

bummer - no hand held - wish i did have one.

Well, to be honest, i'm not entirely sure of those spaded wires on the tach - could i have inadvertantly switched them when replacing the coil?  My old coil had no (+) or (-) on it the way the new one does.  Would my car even run if i had switched the spaded leads on the coil? 

My next (guess) in troubleshooting this is to do one of two things:   1.  get a new tach  (haha!)   2.  disconn battery, pull ignition switch and do some continuity checks on that white wire to the coil -- if i have continuity to the coil end of that wire and it's mounted to the (+) of the coil, I guess I'll switch the two leads at the coil end  <insert uncertainty here>??  then again, if i DID inadvertantly switch the two wires at the coil when i replaced it, did i just smoke my tach and not know it?  UGH!!  I'm tired gang and probably flirting with rambling.....

---

Lou
'76 MGB RD
'70 MGB GT

OK Lou, let's take a step back and describe, please, what connectors you have on the back of the tach.

 Ignore the ignition light and the dial lamp. Except that if the dial lamp is working, you probably have a good ground circuit, still, check it anyway... The car runs, so I don't think the polarity of the coil's connections will matter to the tach.

If the white wire has continuity, and the current to the coil really does pass through the loop in the plastic "thing-um-a-bob" then the tach should work. If it does not, then you need to check that it has solid 12V to the spade connector and that the case is well earthed. After that, we could possibly conclude that the tach is faulty.

I could go on about tach repair - I made a fuss over mine, replacing some of the internal components and recalibrating, but I'll save that story for now (it's here in another thread somewhere). Ebay is another pretty decent option for instruments.

Ed

---

I want my MGB

sounds good Ed - I didn't get a chance to do any continuity checks tonite as i decided to pull my front wheels and inspect the fulcrum pin sleeves and A-arms (all is good - no cracks... whew!).  Anyway, to describe the "back" of the tach:

2 green wires, crimped onto a single female spade connector - those go to the male spade on the back of the tach.  1 black wire with a non-insulated ring-lug on it.  It was (is) slipped onto one of the retaining studs under the thumb screw.  I've got good ground on that.  Then there's the white wire, lopped on the plastic clip with a very small nut on top.  Both the ignition light and dial light work fine.

I'll give that continuity check a go over the weekend...... after we take this little baby for a nice (longer) drive!!    That is, unless my local LBC Sensei hooks me up with a used replacement tach and that one works :-)

I'll keep you posted on what i find out.....

---

Lou
'76 MGB RD
'70 MGB GT

It seems your wiring is probably correct, Lou. Do check the continuity of the white wire AND that you get a solid supply from the green wires onto the spade terminal. As you say, it looks as if your ground is sound.

Most importantly, however, enjoy the drive!

Cheers,

Ed

---

I want my MGB

sounds like a plan - i believe my schematic shows the white wire going FROM the coil, TO the ignition switch, THEN to the tach.... I'll follow it in that order and see what i get, while also checking to make sure a solid 12V on that green pair going to the spade.  Other than that, and the ground, can't imagine what else there could be other than the tach itself being bad.

You bet we will.....it's a LOT more comforting now knowing my A-Arms aren't cracked too -  still need to do some front end work (all the bushings, and rubber, etc.) but that can wait in order to take advantage of the few more weeks of decent weather we have left before the rains.

Also got the new horns wired, working and installed last nite - at least now, i can let others know i'm around haha!  especially when some truck tires are taller than me!!  haha!

Call it selfish BUT, I am definitely enjoying all the head turns, smiles, thumbs-up's and waves I'm getting from other drivers on the road :-) 

Ciao everybody!

 

---

Lou
'76 MGB RD
'70 MGB GT

well, that was a bust - my local expert let me borrow TWO other used tachs - niether worked.  But, then again, not sure if they were operational to begin with either.... I DID however, double check that i have good ground, good 12v to the spade, and the white wire coming off the ignition switch is good continutity to the (+) lead on the coil.... so, perhaps my local guru has a few other tachs up his sleeve and one of those will work.

Question though:  since my tach says "positive earth" on the faceplate, and this car was converted to negative ground, could there be some step in that process that requires an alteration inside the tach?  maybe that alteration was never done?  (anybody's guess at this point).  I'll search the forum here to see if there are any posts regarding converting from positive earth to negative.

Thanks!

p.s.... we went for about a 25 mile ride today - got a little warm around our feet (must be those firewall grommets that are missing) but she drove nice and the scenery was great! 

---

Lou
'76 MGB RD
'70 MGB GT

Sorry to here you're not having much luck, time for some more tach information, Check here for the basics on how they work:

http://www.classictiger.com/techtips/motach.html

There is a conversion that should be done within the tach when one changes from positive to negative earth. There is some info in the back of the Moss MGB catalogue, and also here:

http://www.lotus-cortina.com/electric/convert.htm

Good luck,

Ed

 

---

I want my MGB

Thanks so much Ed! that's really good info -- so, i went ahead and resoldered the connections mention (swapped them) followed the directions explicitly including "reversing" the direction of the white lead and of course, my tach?  she's-a-workin-justa-fine!   I was so afraid it was fried having been plugged in the way it was.  Man, that must mean, whoever converted the car to negative, never got the tach to work - and all the people that drove her all those years afterward didn't have a working tach either!!  Just goes to prove, "some people" just shouldn't own LBCs!!!

So you all know just how lucky i am to have my local LBC guru  -- last saturday, he helped me by tuning and sync'g my carbs - in doing so, he set my idle by "ear" -- told me it was about 1100 rpm or so.  Whaddya think this tach is reading?  1150!!  Now, that's what i call a DAMN-GOOD LBC guy! 

thanks again for all that info Ed - this was really bugging me to have that inoperable.  I owe you bigtime Ed!!

and by the way, my tach was the very LAST electrical item that was not functioning.....      (shhhh!  don't let the Lucas-Gods hear that!)

Ciao il buona fortuna!,

Lou

---

Lou
'76 MGB RD
'70 MGB GT

Excellent! Some good detective work there on your part Lou. It's nice to hear that the gauge wasn't harmed by all those years connected backwards.

Great to hear you have a full set of working gauges. When I first sat in the B, I fell in love with the "proper" instruments, white on black dials, chrome surrounds. A crestfallen feeling accompanied my first drive, as it was quickly apparent that nothing worked. After investigating the professional services for gauge repair and calibration, and noting the cost, I decided to learn more about gauges, and set about repairing them myself.

Ed

---

I want my MGB

Yeah, me too - i just can't believe anyone would drive a stick without an operational tach - especially for that many years!  Guess as a wise person once told me, "they walk among us"...  haha!

Oh man - that's rough!  But it sounds like you took the bull by the horns and gave it one healthy dose of tenacity!  I'm impressed!

 

---

Lou
'76 MGB RD
'70 MGB GT

Guys,

You know what's really funny about this? For most of the history of the American automobile, people drove manual shift cars without tachometers which would have provided useful information. Nowadays, less than four percent of cars have manual transmissions, and virtually every one of those automatics is driving around with a tach. They are only there because they became the fashion when imports, mostly with sticks, made such inroads. But now that they are virtually useless to 99 percent of drivers, who never even glance at them, we just gotta have 'em. What a world...

---

Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon