1971 MGB GT - Engine running shit again - see page 20

[Zelandeth]

2 hours ago, Peter C said:

Destination home achieved.

Another size comparison photo. The MGB looks tiny but my Quashqai isn’t even that big!

That was the one big shortcoming (well, aside from the single digit fuel economy and endless amounts of patience required for any work) I remember from the Jag in daily service - you were so bloody low that trying to see over/around other traffic at junctions/in car parks was an utter nightmare - the bonnet being long enough to land a 747 on didn't help in that regard either.

I don't generally expect a Prius to tower over things!

[chadders]

3 hours ago, Peter C said:

Before I left home, a comparison between the size of the MGB and my wife’s Hyundai. I definitely don’t fancy a head on collision with anything bigger than a push bike.

First destination, my local Esso fuel station, achieved.

Second destination, the 180 degree bend up on the hill in Aldbury also achieved. I am pleased to say that the MGB is performing admirably.

And my first cup of tea in the MGB has also been achieved.

Once I finish my brew I will be heading home via the same 26 mile route.

Loving it!

They're surprisingly robust in a crash, as I found out more than once, and there's a lot of crush space in front of you. I wouldn't want to hit a SUV in mine though given the size of them nowadays.

[Peter C]

Yesterday, on my way home from my trip to Aldbury, I removed the wooden gearstick knob whilst driving and the annoying gearstick hissing noise disappeared. The gearstick knob acts as an amplifier and transfers vibrations from the transmission, which causes a hiss that penetrates into the cabin. 

According to my research on the world wide web, replacing the plastic bush located at the base of the gearstick, packing grease into the top of the gearbox, where the gearstick slots in and applying plumber's tape over the thread of the gearstick, where the knob screws on, all help to reduce / eradicate (depends on which post you read) the noise issue. 

I removed the gearstick by undoing three bolts located on top of the gearbox.

I bought a replacement bush from Moss Europe a couple of weeks ago.

I cleaned out as much of the old grease from inside the top of the gearbox as possible.

And filled it with fresh grease, then reinstated the gearstick.

Finally, I applied some plumber's tape over the gearstick thread. Not sure why it's glowing in the photo!

I will find out whether these remedies have caused any improvement next time I drive the MGB, which will, hopefully, be later this week, once the rain passes.

If the hiss is still present, I may end up replacing the gearstick knob, which is a shame, as I like how it looks and feels.

More soon.

[Peter C]

It’s bloody cold outside but the new number plates arrived this morning and I had no choice but to don my long johns, get my tools out and get them fitted.

I appreciate what @LightBulbFun said about black and silver plates not being cool back in the early 1970s but a soon to be 54 year old MG looks great with these plates on in 2025.

 

[bigstraight6]

Looks great Pete, Devon registered car for bonus points…

[Bmwdumptruck]

O yeh…….spot on with those plates. Just looks right.  👍👍

[plasticvandan]

Regarding the hiss,I remember all my minors and Reliants for that matter made a hiss noise if my hand was sort of cupping the gear knob, obviously a resonant noise/frequency being amplified.it may have been a characteristic of the hard plastic knobs,though i don't recall them making the noise if my hand wasn't on it.The reliant box of course having no such luxury as a bush,just the lever straight into the box.

[Peter C]

If you buy this month's copy of Classic & Sports Car.

On page 28 you will find this plea for help.

[Zelandeth]

On 04/01/2025 at 17:51, plasticvandan said:

Regarding the hiss,I remember all my minors and Reliants for that matter made a hiss noise if my hand was sort of cupping the gear knob, obviously a resonant noise/frequency being amplified.it may have been a characteristic of the hard plastic knobs,though i don't recall them making the noise if my hand wasn't on it.The reliant box of course having no such luxury as a bush,just the lever straight into the box.

The high/low lever on the transfer case on my Lada Niva used to do this as well.  It surprised me quite how much you could modulate the sound just by touching it.  Suffice to say I never actually tried to do anything about it as compared to the screaming noises said transfer box made anywhere above about 30mph a bit of hiss transmitted from the bearings etc really was a drop in the ocean, and I just assumed they all did that.

[Peter C]

I've not been getting on with the bucket seats. They are actually very comfortable and the driving position was spot on but the aesthetics bothered me, especially after I watched the 100th episode of Car SOS, which featured an MGB GT with lovely black original seats. I wanted the same.

I found these and bought a set: https://watfordclassiccars.com/products/mgb-late-seat-covers72-80

I removed the original seats with the non-original upholstery from the loft and got started.

Stripping off the old upholstery was easy.

The foam has seen better days.

Fortunately, I kept all the original seat runner fixings, in labelled envelopes. 

I bought these to fill the holes that I drilled in the floorpan when I fitted the bucket seats.

Fitting the new covers and re-fitting the seats took a few hours but the results are well worth the effort.

The covers need a bit of time to find their right shape. As I don't use the MGB often and nobody is likely to sit in the passenger seat, I've dropped the seats into the maximum reclined position and put some weight on the backrests.

A good result and with hindsight, the right way forward. I wish I had sourced the covers before I bought and fitted the bucket seats.

Speaking of which, does anybody want them, free of charge?

 

[Peter C]

The MGB developed an intermittent misfire last time I drove it, so I bought an ignition service kit from MGOC.

Setting up the points and re-fitting the condenser was fiddly with the distributor in-situ but I managed ok. I set the points gap to 0.15 thou / 38mm.

I fitted the new parts, everything looked ok.

I cranked the engine a couple of times, it wouldn't fire.

I re-checked everything under the bonnet, went to crank the engine over again, the tachometer maxed out, the ignition light went off and now I have no power. No ignition light, no horn, no interior lights, nothing. Something fucked itself. I pushed the MGB back into the garage and called my auto electrician friend, who will come out on Wednesday to take a look at the ungrateful bastard. 

[Marina door handles]

I am looking at that new condenser with great suspicion! 

[busmansholiday]

Top right on the distributor is usually cylinder 1, rather than number 3. Go back to basics and check the timings.

 

Here's a pic off the web showing that and mine is top right also.

[lesapandre]

2 hours ago, Peter C said:

The MGB developed an intermittent misfire last time I drove it, so I bought an ignition service kit from MGOC.

Setting up the points and re-fitting the condenser was fiddly with the distributor in-situ but I managed ok. I set the points gap to 0.15 thou / 38mm.

I fitted the new parts, everything looked ok.

I cranked the engine a couple of times, it wouldn't fire.

I re-checked everything under the bonnet, went to crank the engine over again, the tachometer maxed out, the ignition light went off and now I have no power. No ignition light, no horn, no interior lights, nothing. Something fucked itself. I pushed the MGB back into the garage and called my auto electrician friend, who will come out on Wednesday to take a look at the ungrateful bastard. 

Sounds like a battery earth or it's earthing somewhere it shouldn't around the vehicle. 

Another thought is the ignition switch - if you can get it out of the dash or get behind see if it still in good condition. To test try hot-wiring the car.

The parts you've replaced should not take everything out. Just to check you have the points in the right way round and all the + and - back in the right place?

Only other thing I can think is the coil.

Good luck to your intrepid sparky. Will make a change from moderns.

(There are a lot of crappo modern products on the market - try putting the old stuff back one item at a time to test.)

[Peter C]

1 hour ago, Marina door handles said:

I am looking at that new condenser with great suspicion! 

Intermotor part sourced from a reputable seller.

[Peter C]

27 minutes ago, busmansholiday said:

Top right on the distributor is usually cylinder 1, rather than number 3. Go back to basics and check the timings.

 

Here's a pic off the web showing that and mine is top right also.

I’ve got the cables in the right order.

For some reason, my distributor is in a different position to yours. Not sure how or why but my engine ran great before today!

[Peter C]

14 minutes ago, lesapandre said:

Sounds like a battery earth or it's earthing somewhere it shouldn't around the vehicle. 

Another thought is the ignition switch - if you can get it out of the dash or get behind see if it still in good condition. To test try hot-wiring the car.

The parts you've replaced should not take everything out. Just to check you have the points in the right way round and all the + and - back in the right place?

Only other thing I can think is the coil.

Good luck to your intrepid sparky. Will make a change from moderns.

(There are a lot of crappo modern products on the market - try putting the old stuff back one item at a time to test.)

I agree that my tinkering didn’t cause the electrical failure.

Noted about the coil.

[lesapandre]

Might be a good time to move to electronic ignition? Probably lots of advice online. 

As someone who ran British cars for decades - I share your pain.

[LightBulbFun]

19 minutes ago, Peter C said:

Intermotor part sourced from a reputable seller.

@SiC can correct me if I am wrong, but as I understand it, all modern vehicle ignition condenser are inherently quite shite both in their inherent design the fact they are a paper capacitor which is very old technology and in their construction which means the flying lead often makes a poor connection with the capacitor inside, I think only Distributor doctor do actually decent ones these days?, so yeah I ditto this comment from above 

1 hour ago, Marina door handles said:

I am looking at that new condenser with great suspicion! 

 

 

[Peter C]

12 minutes ago, lesapandre said:

Might be a good time to move to electronic ignition? Probably lots of advice online. 

As someone who ran British cars for decades - I share your pain.

I’ve looked into this.

Some kits are available for less than £100 but Moss Europe charge about £350 for something decent.

Get what you pay for!

[wesacosa]

if you dont want to spend that on electronic ignition I can't recommend these enough 

https://www.ebay.co.uk/itm/201352025609?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Z99PTdcuRNm&sssrc=4429486&ssuid=8AFYP6nlRMa&var=&widget_ver=artemis&media=COPY

keeps the points but as a low current trigger so they last longer and does away with the capacitor which as others have said can be problematic to source, and if anything goes wrong you can just plug a capacitor back in and swap a couple of wires and be on your way again which you can't with full electronic ignition 

[High Jetter]

Best to get it running again first I'd say. The king lead wasn't shorting on that braided hose was it? Hope the leccy loss is easily found.

[Mally]

intermotor rotor arms/condensers can cause problems.

But as above, find the lost electricity first, then swap the bits back one at a time.

[N Dentressangle]

23 minutes ago, wesacosa said:

if you dont want to spend that on electronic ignition I can't recommend these enough 

https://www.ebay.co.uk/itm/201352025609?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Z99PTdcuRNm&sssrc=4429486&ssuid=8AFYP6nlRMa&var=&widget_ver=artemis&media=COPY

keeps the points but as a low current trigger so they last longer and does away with the capacitor which as others have said can be problematic to source, and if anything goes wrong you can just plug a capacitor back in and swap a couple of wires and be on your way again which you can't with full electronic ignition 

I had never seen one before, but someone has put one on my P6. Seems to work well, from what I can see.

[SiC]

4 hours ago, Peter C said:

ignition service kit from MGOC.

That Condenser is shit quality and that rotor arm is shit quality. 

Those condensers often breakdown rapidly. The cheap condenser in the following video is an intermotor one.

 

The rotor arms with the rivet in end up having that rivet conduct through the ceramic into the distributor body creating a short. 

 

Distributor Doctor parts or GTFO imo.

 

Not to say these parts are causing issues right now for you but they will cause issues at some point soon. They are not fit for purpose and I have no idea how they still sell any. Presumably because many cars fitted with them are only ever driven in and out of the garage. 

[SiC]

Intermotor condenser fitted. Started playing up on the M32 so came off as nowhere to stop. Shat itself completely down Stapleton Road, Bristol during morning rush hour. Not an ideal place to be. Pushed out of the way in a side street while I waited for recovery.

It was this incident that gave me strong attitudes on condensers. 

[wesacosa]

1 hour ago, N Dentressangle said:

I had never seen one before, but someone has put one on my P6. Seems to work well, from what I can see.

I'd not either but @spartacus was recommended one when he had the Panda and I've had no issues with it since I took it on

[Peter C]

My auto electrician friend came today (he was due on Wednesday). 

He gave the electrical installation a good once over.

He traced the complete electrical failure to a broken wire at the starter motor. With the wire securely re-attached, full power was reinstated.

With problem one solved, I moved on to the second issue. I pulled out the choke, turned the key and the engine started up first time. Win. Not quite. The engine idled perfectly, ran smoothly on all four cylinders but refused to rev properly. My friend checked over the ignition system, there was a good spark at each cylinder. 

He thought that the problem was fuel, not spark, related. Whilst looking at the carburettors, I noticed a big puddle of fuel under the car.

I traced the leak to the cylinder number 3 & 4 (nearest the bulkhead) carburettor float chamber overflow pipe. 

I removed the float chamber cover, moved the float up and down a few times, everything seemed ok so I refitted the cover and re-started the engine. The leak had stopped but the engine still didn't want to rev. 

I added a bit of oil to the dashpot dampers. Made no difference.

I removed the air filter housings. I noticed that the piston inside the cylinder number 3 & 4 carburettor needed significantly more force to lift compared with the front carburettor. With the damper rod removed, the piston moved freely. I swapped the dashpots around and the problem was passed on to the front carburettor. Would the stiffer piston operation affect the performance of cylinders 3 & 4 sufficiently to prevent the engine from revving up?

With the engine idling (smoothly), throttle openings cause the engine to splutter and shake. It will rev up eventually but it sounds rough.

Any ideas what could be wrong?

On a happier note, putting weight on the front seats for a week has caused the new upholstery to take shape. Nice.

Help!

[Mally]

Have you got too much oil in the damper, is the damper rod bent. is the breathing hole clear in the black screw?

Possibly a seized damper is the problem, but don't see how it occurred by itself.

Float chamber overflow often happens. The needle valves are poor quality these days, Tapping the bowl sometimes stops the leak.

[Peter C]

Just now, Mally said:

Have you got too much oil in the damper, is the damper rod bent. is the breathing hole clear in the black screw?

Possibly a seized damper is the problem, but don't see how it occurred by itself.

Float chamber overflow often happens. The needle valves are poor quality these days, Tapping the bowl sometimes stops the leak.

There wasn’t that much oil in either damper and topping up the oil made no difference.

Damper rod is straight. Hasn’t been touched before the fault developed.

Breather holes in the black plastic caps are both clear.

How can the damper become seized? Everything is moving freely.