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MG MGB Technical - Help with cold starts (non mechanical MGB virgin)

I think I can safely assume that I am the least technical person on this bulletin board. I know practically nothing about how cars work. I can change a wheel & fill the windscreen washer, but aside from that, my technical expertise is as follows: engine in front, driver in cabin, spare wheel in the boot/trunk. You get the picture...

In spite of my lack of expertise, I do have an abundance of enthusiasm, so I recently fulfilled lifelong ambition to purchase an MG. Picked up my 1973 MGB GT last week. I did get a mechanic (who knows about MGs) to look it over first & he said it was in pretty good shape. Some minor bodywork, but engine & overdrive were "sweet as a nut".

My problem is this: the car is slow to start when cold - often requiring a number of turns until it finally fires after 5 or so minutes. It was fine until this morning - it just would not start. The outside temperature was 2 degrees Celsius / 35 degrees Fahrenheit - quite common in Ireland right up to May/June.

Is this cold starting a common problem? I assume there a number of possible reasons for this, so any advice would be greatly appreciated.

On a final note, I am hoping to use the MG as an everyday car. Before I bought the car, I did some research on MGs, which seemed to indicate that MGs were reliable, and were amongst the most usable of all the UK classic cars (provided the body work is properly cared for). I live close to where I work, so my annual mileage does not exceed 5,000 per year. There is a local mechanic who works on classics. He has advised me that the car needs a minor service every 3000 miles & a major one every 6000 miles. This seems fair enough to me, but I was kind of hoping that might be enough to ensure the runs well & car starts in the mornings. I am keeping my normal everyday car for the time being (as a precaution), but would hope to sell that & keep the MG as my only car (my wife has a people carrier for family driving). Am I being unrealistic in my expectations of running a 32 year old car as an everyday vehicle, given my complete lack of mechanical knowledge? I have loved these cars since I was 6 years old (I'm 33 now), so I really hope I can keep it on the road.
Mark

Mark
As you may recognize, a lot of contributors to this board are hobbyists who enjoy working on cars. All older cars required more regular maintenance than newer cars. You will be getting your old car serviced - in the ordinary course - more than is scheduled for a new vehicle.

The MGB was known for its decent mechanicals and good reliability for the time. Now, no one would buy a car with common electrical problems, doors and latches that regularly require adjusting, lubing etc. an engine that requires a "tune up" (with modern plugs) at least every 20,000 miles, and perhaps more frequently to reduce the valve clicking noises to tolerable levels, carburetors with complex linkage for starting and running which require adjustment from time to time. Chassis lube every 3 to 5 k miles, shock absorbers (dampers) that may leak and need refilling, large amounts of wind noise once you pass 60 mph, wire wheels that are almost inpossible to perfectly true and balance. Finally without some modifications to suspension tires and wheels they don't handle as well as your wife's people hauler. The fuel mileage is poor compared to a 2400 lb modern car.

If it hasn't already been done, you should convert your ignition system to an inexpensive electronic system. That will be the greatest step forward for reliability and will pay for itself in short order by avoiding "tune ups".

This is a hobby and you will pay the price for your vice.

Barry

PS your car should start quickly and easily cold or warm. You need to find a mechanic who has experience with outdated carbs, fuel pumps and electrical systems. This once common knowledge is now held by a few grey beards.
Barry Parkinson

Mark,

Despite owning two other cars with more modern drivetrains, I keep ending up driving my '71 B roadster while the other two are having problems. Only once in the last 2 years has the B failed to start when I demanded it, and that was when snow had drifted under the bonnet and the cold had lowered the battery voltage too far. A jump start from a tractor soon got me going again, and I suspect if I had a single 12V battery rather than the two poorly 6-volters, I wouldn't even have had a problem.

When I had the same engine in my '67 BGT, which has a 12V battery, I could come back to the car after months standing outside during the winter and it would fire immediately.

They can be reliable if everything is kept in good order - but therein lies a challenge!

Best of luck,
--
Olly
Oliver Stephenson

Mark,

I run a 1973 MGB, one son runs a 1978 MGB GT and another son runs a 1965 AH Sprite.

They are all daily drivers and are totally reliable - servicing is cheap and easy (no ECUs, cats or cambelts), all can keep up with motorway traffic and all go on long trips without special preparation (the GT did 1800 miles in three days without a hitch and at 37 mpg!)

Get the car sorted out (expect a few problems but don't get disheartened) - starting should be quick and easy - get the ignition and fuel mixture checked and adjusted. The Aldon Ignitor electronic ignition is a good system - no need to go for the more expensive Lumentition systems.

We are all here to help - join the local club too - the social side of these cars is just as much fun as driving.
Chris at Octarine Services

No one has mentioned the cold starting problem. Make sure you're using the 'choke' (cold starting system) correctly and that it's adjusted properly.
I used an MGA and then an MGB as daily drivers back in the 60s and early 70s with no problems, even in Ontario winters. The only time one of them failed to start was when the temp was about -30C and I'd let the battery get a bit weak. I still have a '58 MGA and a '67 BGT, I use them as daily drivers in the non-salt months and I prefer them to any modern vehicle, although I'll certainly admit that most modern stuff, even Yank tanks, can out-run and out-corner my MGs.
Fraser Cooper

Thanks guys...

Barry - Good point about the electronic ignition. I'm leaving the car in for a full service this week, so I'll look into getting that done. You're right about paying for my vice - I fully expected to come up against this type of problem. I'm hoping to evetually do as much of the routine work myself as possibole - like you said, that's half the fun.

Olly - I just called the previous owner about the battery. He mentioned that the battery may not be great. Mine has a 12V instead of te 2 x 6V.

Chris - 1800 miles in three days without a hitch and at 37 mpg?!.. now that's cheered me up!
Mark Whelan

Especially in winter, a weak battery can cause starting problems. The starter motor is inefficient compared to modern starters and needs a lot of current to crank the engine so the battery needs to be in good condition to start on cold mornings.

dave

Mark--

Don't worry, you'll learn. Eight months ago, I was in your position. This weekend, I'll be rebuilding my clutch hydraulics; a few weeks ago I swapped out my starter; later this summer, I'll be installing a new carburetor. None of them great feats of auto mechanic wizardry, that's for sure, but not bad for a guy who hadn't even changed his own oil before I bought my MGB.

Anyhow, I second the motion to check that you're using the choke properly. Exact usage probably depends on your carb, but on cold mornings, I generally pull the choke all the way out, start it (it NEVER takes more than a few seconds), put the choke in a little so it doesn't die. Ease in the choke as you drive or as the car warms. When your temp guage is halfway between "C" and the middle, the choke should be all the way in.

I mention that because it got me, too; I'd always driven modern cars, and the PO declined to give me a quick lesson in choke usage. I was confused as hell for the first few months.

If you're choking correctly, check the battery. The easiest way I've found to check the battery is to go buy one at Wal-Mart (or whatever the Irish equivalent is, if there is such a thing) and swap in the new battery. If your problem is solved, you found the culprit. If not, return the battery within 90 days for your money back.

Hope that helps, and welcome to the happiest place on earth.
Chris St. Pierre

Not only check to see that you are using the choke properly, but that it was setup correctly previously. Don't assume too much about its care in the past, even if it seems generally to be in good order. SU carbs still befuddle some folks and not all owners or mechanics check their work against the shop manual. BTW, if don't have one, now is the time to get one. I recommend the Bentley's reprint of the factory manual and then also the Haynes manual. Haynes is not always as complete, sometimes more intuitive to some, while the factory manual is reasonably complete, but not always as transparent to some owners and neophytes. It is just good to have both.
Bob Muenchausen

Chris - My first ever car had a manual choke. It was an old crock that always needed full choke to start (and even then didn't always start!). Since then, my cars have been modern Japanese computers with wheels with no need for manual chokes.

So, it was was like a bad case of deja vous when I saw the choke on the MG's dash. The PO advised starting with full choke and clutch in full. He did mention that she always took a couple of turns to get started, so that new electronic ignition is looking increasingly attractive...
Mark Whelan

hi there,

I have my first own MGB GT since this summer and as it was a restoration project had few problems at the beginning in the humid and windy weather of the channel islands so as I wasn't a mechanical expert I did some simple tricks: removed the battery, cleaned the contacts and put some copper ease on the contacts, then always put a large piece of carton in front of the radiator when I don't use it, wipe the humidity with a dried rag before trying to start it (so spark plugs and carburetors), knock the fuel pump gently with a hammer and the START!! and so I never needed to choke it to start.
hope it's help!
ALexia
Alexia

Fraser's comments about cold starting probably would take care of your problem. In the cays before electronic ignition systems, MGB's started just fine. You just have to remember to keep them tuned up properly. That means new plugs, points condensor and rotor at at least the recommended interval (modern cars don't need this and we tend to forget this isn't modern. Their plugs last for two to three times that of conventioanl igition cars as well). Follow the starting proceedure in the owner's manual. Carbs need to be adjusted properly. Choke linkages wear over the years and you might not be getting full travel when you pull out the knob. Get it back to specs and you should be able to start it no matter what the temp is in Ireland.
R. L Carleen

Mark - I think that everyone has pretty well covered all the bases to help you get the car started when cold, but in your last post, you said something that caught my eye. You said "The PO advised starting with full choke and clutch in full." I agree with the full choke, but instead of the clutch in full, the car should be in neutral and the clutch left out. Because the MGs use a carbon block in place of the more modern roller bearing as a throw out bearing, they tend to wear out quickly when the clutch is used excessively. Unless there is some excessive drag present when the clutch is out with the transmission in neurtal, the clutch should be left undepressed when starting. Further, when driving, the clutch should only be used when changing gears. When stopped at a traffic light or for traffic, get in the habit of shifting into neutral and letting the clutch out for the duration. Good luck - Dave
David DuBois

The choke cable (outer on early cars, inner on later cars) causes enrichment by pulling on a lever on a shaft. The lever is only relatively short which means the shaft rotates quite a long way, more than 90 degrees. Unless the cable is set up correctly the lever can have reached the limit of its movement, and so won't turn the shaft any further, some time before maximum enrichment is reached, and this causes lack of enrichment and difficult cold starting. The correct position is that when the enrichment is half applied, the lever makes a right-angle with the cable.

On HS cars I find that whilst I start it with full choke, as soon as it catches I can push it back in about half way, then gradually reduce it to fully off as it warms. Too much choke will wash the oil off the bores and cause rapid wear. By contrast HIFs seem to have less enrichment, and on my V8 at least it needs full choke for a few seconds and only gradually reduced from there.
Paul Hunt

Thanks all for your help. Seems it was a battery problem. I took it out & cleaned the contacts & tightened the connectors properly (they weren't as secure as they could have been). Seems to have done this trick - she started no problem last night & again this morning.

Also, she didn't need any choke to start - is this because there was already enough petrol in the engine from trying to start her so many times the previous day?.. or has fixing the battery miraculously eliminated the need for choke? (Don't laugh - I do state at the top of this thread that I'm not very mechanical)

Dave DuBois - I noted your point about the clutch. I wouldn't ihave tyhought of that, so thanks for the tip!
Mark Whelan

Mark,

A well tuned car can start without any choke at all, especially on mild days like today.
dave

Mark--

Do you have the old helmet-style battery connectors, or the newer hoop-style connectors? I've heard of lots of people having problems with the helmet-style connectors coming loose -- you might want to convert those over when you have some spare time.
Chris St. Pierre

I second Dave DuBois' comments about the clutch. There's more drag on the engine with the clutch pedal in than just turning the input shaft. Make sure it's in neutral though!
A further second on never holding the clutch in at traffic lights, etc. It's not only hard on release bearings, it's a dangerous practice.
Fraser Cooper

dave"A well tuned car can start without any choke at all" Tuned for what? A car tuned to run right once warm, needs a rich mixture durring a cold start. RIC
R E L Lloyd

I second Dave's clutch comments too. I would only add that getting in the habit of shifting out of gear and taking your foot off the clutch pedal when the car is running and at rest (as at a stop light) and then engaging the trans when actually needed will make the carbon throwout bearing last much longer than most of us Yanks are used to. Over here, we seem to seldom take a car out of gear when halted and just keep the clutch pedal mashed until the light turns green. That is quick death for an MG throwout bearing.
Bob Muenchausen

I second REL's comments. Whilst on a very warm day you might not need choke to start, I don't think that includes a UK morning in March, 20 degrees at 2pm notwithstanding.
Paul Hunt

I concur about the use of choke. If your car starts on a cold morning without choke, it is tuned far too rich. The SU has no accelerator pump so, when tuned for best effiency at running temps, is much too weak when cold to start the engine without enrichment.

HOWEVER, Mark was right that constant cranking of the engine and not starting does prime the cylinders with a combustable mixture which, in my experience, will allow an instant start next time round. Do make sure your battery terminals are clean and tight. You need all the power you can get.

Mike H
Mike Howlett

Just an observation. based on the cars I have driven, although they have correct carb settings with regard to emissions (verified with computer thingy at a garage) and one of them was using K+N filters on standard needles, both would start without choke on a pleasant (15 degrees centigrade+) day, and that would include from cold.
dave

Very good advice regarding the use of the clutch from Dave DuBois, you will actual hear the engine note drop
slightly when the clutch pedal is down.
When ever the car is not motion, it should in neutral and the clutch pedal released.
Con.
Con ODonoghue

This thread was discussed between 14/03/2005 and 18/03/2005

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