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ATE399J

Original Poster:

566 posts

125 months

[news] 
Thursday 4th October 2012 quote quote all
All,

Just bought a BGT (1979). Have done just over 100 miles in it and the performance has been going down hill. It now seems to have little power and pops and bangs if you put your foot down hard.

Could be one of many things, a hatred of un-leaded (although prevoius owner assured me it had an 'unleaded' head), badly tuned carbs or ignition.

Assuming the timing is out, what should it be set to for a '79 running unleaded?

Phil

na

7,840 posts

122 months

[news] 
Thursday 4th October 2012 quote quote all
sounds like it could be set up incorrect or just muck from not being run for a while or any real distance

set tappets, points, plugs, timming and then mixture in that order

clean air filters

if you haven't already got one get yourself a copy of the Driver's Handbook (Ref: 0053) http://www.mgocshop.co.uk/catalog/Online_Catalogue... it will tell you all about above and a lot more you need to know about your car better than Haynes for all but repairs - Handbook for prevention, Haynes for repairs - and Haynes usually has errors and ommisisions so factory workshop manual is probably better, in paper form or on a DVD

these no really settings that firmly apply to a used 30 year old car, unleaded makes no odds to this, the settings you make will be on the octane of what's in the tank

there are plenty of threads on PH on new owners of Bs and Spridgets (some recent), also there's the MG BBS and 200+ John Twist videos - http://www.youtube.com/user/Universitymotorsltd

and Paul's excellent B site - http://www.mgb-stuff.org.uk/hometext.htm

I strongly suggest you regularly, throughtout the whole year, drive the car as this will help the car and you to learnt what it is (or should be) fully capable of, and very improtantly that you carry out fully and proper servicing (see Handbook), maintenance and repairs

carry out a staggered 36-mile service/check (sse Handbook) ASAP whilst continuing to use the car

no cosmetic work or upgrades or improvements (unless required) for at least 12 months of regular driving as you might need that money for more important maintenace or repairs

a B shouldn't be slow, poor handling and unreliable it's the previous and some present owners that make it that way, please don't be one of those

the engine and carbs aren't important items on the car the brakes, tyres, steering, suspension, lights and windows are

I've got a few notes if you want them and aren't put off by my directness (PM me)

good luck

chormy

615 posts

84 months

[news] 
Thursday 4th October 2012 quote quote all
www.mgexperience.net great site.

A good basic service of the ignition system check timing! Carbs well many things been said on these check they are balanced , ie remove air fitlers and listen with a pipe for same air sound being drawn in.
All I can say is have fun they are a labour of love.

jagracer

7,676 posts

124 months

[news] 
Thursday 4th October 2012 quote quote all
ATE399J said:
All,

Just bought a BGT (1979). Have done just over 100 miles in it and the performance has been going down hill. It now seems to have little power and pops and bangs if you put your foot down hard.

Could be one of many things, a hatred of un-leaded (although prevoius owner assured me it had an 'unleaded' head), badly tuned carbs or ignition.

Assuming the timing is out, what should it be set to for a '79 running unleaded?

Phil
Could be the ignition too far retarded or carbs running too lean or st in the jets. Assuming It's an 1800 then ignition at 8-10btdc on a strobe at tickover would be a reasonable starting point to get it running reasonably well, then go from there. What sort of unleaded are you using and is it an HC or LC head?

Edited by jagracer on Thursday 4th October 19:54

Moikey Fortune

1,568 posts

124 months

[news] 
Friday 5th October 2012 quote quote all
I'd get a new condensor and fit that first before you start adjusting things

It could be as simple as that

Best of luck

oh yeah and don't throw any of the olds parts away that you do replace until you're confident the new bits work properly
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na

7,840 posts

122 months

[news] 
Friday 5th October 2012 quote quote all
Moikey Fortune said:
I'd get a new condensor and fit that first before you start adjusting things

It could be as simple as that

Best of luck

oh yeah and don't throw any of the olds parts away that you do replace until you're confident the new bits work properly
very, very rarely condensor - more likely settings or lack of from previous owner or lack of use

thumbup good point about not trusting new parts, including new condensors!

or assuming present parts are correct or working properly - I have notes on such biggrin

AtticusFinch

4,197 posts

71 months

[news] 
Friday 5th October 2012 quote quote all
ATE399J said:
All,

Just bought a BGT (1979). Have done just over 100 miles in it and the performance has been going down hill. It now seems to have little power and pops and bangs if you put your foot down hard.

Could be one of many things, a hatred of un-leaded (although prevoius owner assured me it had an 'unleaded' head), badly tuned carbs or ignition.

Assuming the timing is out, what should it be set to for a '79 running unleaded?

Phil
Unlikely that the timing or carbs have just gone off. Probably somthing electrical points, HT leads, plugs, coil, condensor, rotor arm etc.

Check the simple things 1st, if your not sure enlist some help (local owners club maybe)

As Nigel says carry out a service as soon as possible this will eliminate most problems.

ATE399J

Original Poster:

566 posts

125 months

[news] 
Friday 5th October 2012 quote quote all
POINTS!!!! it was the bl**dy points. Seems to go better WITH a gap!

na

7,840 posts

122 months

[news] 
Saturday 6th October 2012 quote quote all
na said:
set tappets, points, plugs, timing and then mixture in that order
so you didn't bother with the tappets as then laugh

points could well close up again so check them after 50-500 miles, CB points were (are still?) one of the poorly made components so if they continue to play up swap for a good old set or buy new from some where decent like the Distributor Doctor

after the 12 months of use I recommend getting rid of the CB points and as the dissy itself could well be old and worn (if not replaced with a good rebuilt unit) I'd swap the whole dissy for a 123 (fully) electronic unit as the dissy were well out after a few year of use when the car were new and few owners would bother with lubing the cam and even less oiling (see Driver's Handbook for both), then of course the springs stretch, weight out of line, ect.- that's one reason why timing isn't by the book

good thing about these cars is that normally engine running faults are usually only fuel or electric and both systems are reasonably simple

faulty points is just one thing you would pick up doing a 36k-mile service/check

it's going to be a nice weekend so one day servicing/checking the other driving, enjoy (well the driving at least)

ATE399J

Original Poster:

566 posts

125 months

[news] 
Saturday 6th October 2012 quote quote all
Yes, did tappets, timing, checked dizzy cap, rotor arm & condensor (all looked new). New plugs and also greased front suspension.

na

7,840 posts

122 months

[news] 
Sunday 7th October 2012 quote quote all
ATE399J said:
Yes, did tappets, timing, checked dizzy cap,
thumbup


ATE399J said:
rotor arm & condensor (all looked new)
if new keep an eye on those


ATE399J said:
New plugs
good (correct type(?))


ATE399J said:
and also greased front suspension.
always a good idea to reeegularly do those

brakes and tyres

batteries and coolant system

and plenty of driving smile

- 7 days into SORN season and already 7 good driving days (well here at least) biggrin

ATE399J

Original Poster:

566 posts

125 months

[news] 
Monday 8th October 2012 quote quote all
na said:
- 7 days into SORN season biggrin
SORN season? The only SORN season I observe is "Salt On Roads - Nasty"!!

Yeah, did a fairly good check over pretty much all you've suggested. Major problems left are that the fuel gauge doesn't read anything (gauge appears OK on the bench) and it idles at about 2000 rpm; disconnecting the vacuum advance has it drop back to about 800 so I think there's a problem in the dizzy - a spring missing somewhere?

SMGB

786 posts

27 months

[news] 
Monday 8th October 2012 quote quote all
na said:
very, very rarely condensor - more likely settings or lack of from previous owner or lack of use

thumbup good point about not trusting new parts, including new condensors!

or assuming present parts are correct or working properly - I have notes on such biggrin
If you can get a NOS Lucas condensor then yes +1. The Chinese pattern parts are so bad I wouldnt call them censored as that would be giving censored a bad name. I have a Boyer Bransden igintion amplifier on my car as it doesnt need a condensor (+ve earth). You can also get a race quality external one and i have one mounted as a spare ready to put in circuit if its needed. I got mine from MG Motorsport but I think Peter Burgess now offers them.
Have you checked for crud in the carbs, SUs are so easy to service, and set up. I use Britishcars.org for MGB techie stuff.

na

7,840 posts

122 months

[news] 
Monday 8th October 2012 quote quote all
quite agree about poor quality condensors

the problem turned out to be CB points, those of course can be as bad as CB points

I've mentioned old dissy problems, Distributor Doctor offers 'Re-building, re-conditioning and re-curving are all catered for either to “Clinically Accurate” original factory specifications, or modified to suit developed engines.'

personally I'm very happy with my fully electronic 123 dissy that does away with CB points and condensor and the old worn springs and weight - Peter Burgess sells them

you can also possibly get poor quality flasher units, column switches appear to be much better now, rubber is (was?) rubbish TRE, steering rack gaiters, drop links, fuel hose - there's a learning curve with suppliers too

ATE399J

Original Poster:

566 posts

125 months

[news] 
Wednesday 10th October 2012 quote quote all
Broken it again.... No clutch pedal. Usual issues of a car that's not been used much for a while.

na

7,840 posts

122 months

[news] 
Wednesday 10th October 2012 quote quote all
fault of the previous owner really

you're begining to see why I say the 36k-mile service/check ASAP

so, seals, m/c, s/c, rease mech, fluid, pedal

the quicker you get it sortedthe quicker you can get passed the next lot of niggles smile

ATE399J

Original Poster:

566 posts

125 months

[news] 
Wednesday 10th October 2012 quote quote all
Yes, you're right but I don't think you'd change the seals at a service would you?

I fully expect bits to keep falling off for a month or so of "proper" use and then for it to become more reliable. Certainly my Tiv went through this but isn't too bad now (famous last words).

I'm just wondering what will be next! I have receipts (from the prevoius owner) for most of the brake parts that might give up the ghost and the tyres are good / new.....

na

7,840 posts

122 months

[news] 
Wednesday 10th October 2012 quote quote all
ATE399J said:
Yes, you're right but I don't think you'd change the seals at a service would you?
weeeeeeeeeeeell, have you been reading the Driver's Handbook(?) - for brakes you'd have originally been changing seals at 36k/3years along with the flexihoses - not that I'd recommend changing at the moment with the poor quality of some rubber parts and components, you'd also be checking for pitting

the point is you've got a car you don't know the history of so you have to check everything and cross reference any information you have with what you can actually see

if you can get a copy of this at a sensible price it covers full servicing, very useful tick list for when you first have the car and then with experience of ownership and more knowledge you can cut back a little on what they suggest - http://www.amazon.co.uk/MGB-Step-step-Service-Guid...

ATE399J said:
I fully expect bits to keep falling off for a month or so of "proper" use and then for it to become more reliable.
laugh

I'd give it a bit longer, 12 months of regular use should do the most of it

ATE399J said:
Certainly my Tiv went through this but isn't too bad now (famous last words).
you've done it now smile

ATE399J said:
I'm just wondering what will be next! I have receipts (from the prevoius owner) for most of the brake parts that might give up the ghost and the tyres are good / new.....
if you do the full 36k-mile service/check (plus the bits I add) you'll prevent a lot of things and also might see more things you can prevent

I never see the point of 'macho' repairs at the roadside I prefer prevention of breakdowns as do wives and girlfriends

never assume because a component or part is new that it can't be or wont go faulty, is fitted correctly or is even the correct part - just check

the thing is do you want a car that goes or one that goes well - many classic owners have cars that are not going as well as they should for various reasons, lack of use and driving experience in them and lack of full and proper servicing, maintenance and repair - one of the main problems with classics is their past and present owners (I'm not putting you in this camp)

ETA: BTW if you follow advice and Driver's Handbook you should be able to change your profile on the car - no they're not all slow, the slow, poor handling unrliable one are kept that way by the current owners, they're not fast as standard but they're not slow and correctly set up should handle well and with full and proper . . . (sublect to new parts) they should be reasonably reliable

Edited by na on Wednesday 10th October 16:13

ATE399J

Original Poster:

566 posts

125 months

[news] 
Thursday 11th October 2012 quote quote all
No doubt there's plenty here on this subject (but can't get the search to work properly) but I've seen lots of comments about difficulties in bleeding the clutch hydraulics - suggestions of "back bleeding", connecting the brake bleed to the clutch slave bleed and pumping fluid in using the brakes and other "unusual" suggestions instead of the standard method.

Is this all old wives tales or is there an issue in bleeding the system?

Phil

SMGB

786 posts

27 months

[news] 
Thursday 11th October 2012 quote quote all
I cheated and went to Dave Pymme the Midget racer, I know him theough the MGCC and his garage near Marlow is local to me. With an Eezibleed and the car on a hoist it was a 5 minute job. At home on axle stands with the "push the pedal NOW!" method it can be censored impossible. The slave pipe is fixed in such a way that you cant fully bleed it that way, hence the fill via the bleed nipple dodge.
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