MGB & GT Forum

Hi All,

My '74 MGB GT seems to struggle to turn over when starting, although this isn't every time. I'd say 50% of the time it spins super quick and fires no problem, but the other 50% it turns over so slow that its worrying and recently has even failed to start at all.

The battery is on a constant charge with one of those special chargers and i have had it tested where it passed 100%.

I assumed my battery was dying so bought another one with higher rating, and this did make the engine turn over better but it did still struggle where it really shouldn't so i took this back for a refund and starting wondering about the starter motor instead.

My question is what rating of battery do you all use as .........

My one is 30Ah with 300 cold crank.
The new one (returned) was 45Ah with 400 cold crank
The Haynes book says 51 to 66Ah which makes me think my starter is ok and i just need to find a more powerful battery

I have a size 063 and nothing bigger than that will fit !

Thanks in advance.
Carl

The CCA (cold cranking amps) is the more important value when it comes to starting the car

I've got a 202 sized 44Ah 400CCA battery in mine and it spins it over quickly and has no problems starting at all.

If the 400A battery isn't doing well enough for you, it might be worth checking the earth connection at the battery and the engine just to make sure they're clean and tight

The Westco I use is rated at 450, but the moss note says the MGB only needs 300 to 330. Your 400 CCA should be fine when topped up and in normal temperatures.
Any chance your timing moved and advanced to the point it's kicking back against the starter?

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__________________________
1970 MGB Black Label OD, APT VP12, Fidanza Flywheel, Flowspeed Head, Hilton AUD405 HS4 SU's, Schlemmerized Distributor, Pertronix Ignition, Saturn Alternator, 15" Dayton Wire Wheels, Falken ZE 912's, Falcon Big Bore
1972 MGB GT Blue Label OD, APT VP14, Fidanza Flywheel, Flowspeed Head, HIF SU's, Schlemmerized Distributor, Points Ignition, Saturn Alternator, 15" GC360 Wheels, Falken ZE-950s, Peco Exhaust, Frontline Costello front valance

What I find amazing is that you purchased a new battery and then returned it for a refund when it didn't solve your problem. Is that the way business is done in the USA or is it just the way YOU approach buying items. Shouldn't you have ascertained that your old battery was faulty or do you now buy (more like borrow) a starter motor, a battery lead, solenoids etc and just return them when they don't solve your problem? Is this fair to the seller?

Carl,

I had a similar issue on my car. After hunting for all kinds of battery drains and ground issues, I came up dry. I was always on edge when I went to start my car. Then, as I was pulling my engine to do a transmission swap, I noticed that the two long screws in my starter body were loose, allowing the starter to drag '50% of the time'. Tightened things up and never a problem starting since. It's a quick easy thing to check. Maybe you will get lucky.

David

X2 hsim4mahgod
Who accepts a battery return????


stock equipment battery spec was 345 CCA

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Michael J. Caputo
'79, '77, '76, '74.5 (rubber dual SU), and '73 owner. Extensive experience in 12v Audio System design and installation. Vendor of Regalia and Promotional Products since 1993. Supplier of Accessories to MOSS. Forum Member since 2009; with a warped sense of humor since birth. Publisher of the annual MGB & GT Calendar, mailed worldwide.

C'mon Mike... Go easy on the guy. Not everyone on the site has as much troubleshooting experience as you & I may have. The man is just looking for some help...

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Those who confuse Burro and Burrow don't know their @ss from a hole in the ground...

Thanks for your responses, it sounds as though my original battery should be ok then so I'll check over all the earth straps, mounting bolts, and clean up the starter motor connections to see if it makes a difference.
The connections are ok at the battery end as i checked those when fitting it.

I don't think its a timing issue as i have an electronic dizzy and when it starts it runs perfect, I will of course check though next time its running.

Hopefully it will be something simple like the loose bolts so will check these asap.

As for returning the battery Michael, thanks for your 'opinion'.....have you never returned clothing etc if you changed your mind.....its the same process and i was back at the shop within an hour so they were happy to accept the return. In the UK we call that helpful and good for future business. I notice you didn't even answer my question so hope you enjoyed your moan.

I'm sorry Carl, but I have NEVER returned any item whatsoever unless it was faulty or not as described. There is a cost when you return an item which is passed on to all other buyers. You may think it is insignificant when you return a battery but think if a thousand or more items were returned in a year for a refund.?
My point apart from the return issue is that maybe you should have done some better diagnosis of your fault before you started replacing items. Remember the old saying "hasten slowly". There are numerous MGE members who will gladly assist you in your fault finding and by doing the job methodically you will also learn a lot more not only about electrics but also about your vehicle.
I would also suggest that you may have found answers in the MGE archives. Rushing into a repair especially electrical could see serious damage resulting which in turn could make a simple inexpensive repair a horrendously expensive one.
Hope you have your vehicle running smoothly in a very short time so you can enjoy it in your forthcoming summer months. Mike

Working in a shop in the UK that sells car batteries, if someone wants to return a battery that isn't necessarily faulty I can't say to them 'you only just bought that and theres nothing wrong with it, no returns' I don't think it really costs the company anything to process that return, we'll check the battery and if its up to new spec and in good condition then it can be sold again, no problems there.

I will say to carl though that if you want a check of your current battery doing, you can go into a Halfords and they'll be able to check it over for free Can also do an alternator and starter check, but this didn't quite work for my car as the idle speed was so low the tester thought the car was a diesel... haha

Hey Carl,

I just wanted to tell you that I actually have returned a few items during my lifetime. One of them was actually a package of "Fruit of the Loom" underwear. Waistband was not comfortable. Guess I'm not the "perfect shopper"... However, I have NEVER broken the speed limit in my MG!!!!

Paul

P.S. Hope you get her up and running man! Enjoy...

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Those who confuse Burro and Burrow don't know their @ss from a hole in the ground...

Some different advice, how about buying a "Specific Gravity Tester". This will check the electrolyte solution in each cell of the battery,(after you have charge your battery, and show you if it is really good battery or not. Most shops I deal with will check your battery and tell you if it is good or not. Not offering up that service opens up this shop for returns. I would never advise buying a battery "Pre-charged" with the electrolyte already placed in and charged up. Even if you do this, you still must charge the batter, at no more than 2 amps. 1.75 amps, even better, till charged, then check the specific gravity.

Personally, I don't do the "borrow and return method", because the next guy is getting the starter you installed, used, and is paying top dollar for, it isn't fair. Also, the parts store will have no respect for you, will never give you any deals, and you will be know as "that guy". I always get get preferred customer prices, that is to say, whole sale prices, which would allow me to make even more money if fixing someone elses car. It is much better to learn what you are doing, than driving up the cost of a business, doing business. I had my own repair shop for 10 years, and also sold parts, for electronics. I never, ever, returned money on any electronic item unless it proved defective. That is stated in most parts shops, "No Returns on Electric, or Electronic parts unless part is defective, and then the part will only be exchanged for the same part number. This discourages this bad habit, or practice.

These work great. They make a similar unit for radiator anti-freeze:

If a shop tells you your battery tests out 100% why did you replace it?

I think your will fnd your issues among the grounds and hot connections at the starter.

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Michael J. Caputo
'79, '77, '76, '74.5 (rubber dual SU), and '73 owner. Extensive experience in 12v Audio System design and installation. Vendor of Regalia and Promotional Products since 1993. Supplier of Accessories to MOSS. Forum Member since 2009; with a warped sense of humor since birth. Publisher of the annual MGB & GT Calendar, mailed worldwide.

Or the starter is failing and drawing too much power at times.
Typical group 26 battery in the roadsters puts out 525-540 CCA

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Hoping to get under the car and check the starter connections later today so will let you know what i find.

Result with the Fruit of the Loom undies Paul ha ha