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MG Midget and Sprite General - Dammit!!

Fitted new fuel pump this morning, and it works - there's definitely fuel being sucked up into it. However, I can hear something sparking under the bonnet when I turn the key - and with no-one to look at what's sparking, I don't dare keep trying. Would be very upset if it caught fire after all the work we've done!!
Ally

When you turn to crank I assume? Loose lead on battery, solenoid, starter or HT lead. Touch anything under there? e.g. take the battery lead off when doing the pump?
Greg H

The battery was disconnected when I changed the fuel pump. The only other thing I fiddled with was the vacuum pipe to the distributor - didn't touch any wires.

The old fuel line (fuel pump to tank) is still floating around - it popped up and introduced itself while I was fiddling with the awkward bolt on the fuel pump. As last weeks fireworks were caused by the shorter fuel line (now removed) - I'm wondering if it's this that's touching something and sparking - but I can't see from the drivers seat!!
Ally

If you have electronic ignition fitted you'll tend to hear a spark if the engines around TDC when you switch on the ignition.
F Pollock

Oh! Maybe that's what it is, and I m just being a clueless numpty!
Wouldn't have thought anything of it if we hadn't had the issue with the old fuel line shorting last weekend.

Am a bit paranoid about starting the Great Fire of Maidenhead!
Ally

better to be safe than sorry petrol and sparks are not a good combo

check all leads and connections are clean and tight

you might have accidentally knocked something loose or taken something off and forgot to put it back firmly or forgotten that you touched something else because your mind is on the fuel pump

start at battery and work your way through the ignition system checking for loose or disconnected

connections and leads on battery, starter soloniod, starter, HT leads, (dissy cap? or inside dissy?) low tension wires

if all are clean, secure and protected then don't start the car without someone looking for the cause

the damp can highlight stray electrics too
N Atkins

To start the car while under the bonnet it really simple

Make a 12 inch jumper wire out of 18 to 22 gauge insulated electrical wire with a female spade connector crimped on one end

Next on the selinod...there is a white with red stripe wire just below the smaller brown wire...remove the white with red striped wire and hook your jumper wire to that post

Next put the key in the ignition and turn on

Next take the bare end of your jumper wire (previously strip about 1/2 inch of insulation)...and touch it to the top post of the selinoid that has the battery starter cable bolted to it

It will start right up... Or disconnect the coil lead to dissy and you can roTat the engine without starting and look for your electrical popping while head under bonnet...

Just dont get your long hair in the moving parts

Prop
Prop

Btw....i noticed you used the word "dammit"...your progressing nicely with in a year im sure your vocabulary will grow to include much more colorful langauage....thats when you know you have a serious addiction to spridgets.

If you need suggestions ...let us know imsure we all can provide you a an indepth list...


Hang in there ... Those words will devolop in no time

Prop
Prop

Prop you're back with flying colours

Ally needs to look for the sparks not create more, you want a firework diplay :)

if you're not confident doing this all these sparks wont help
N Atkins

I've found the spark - it's coming from the ignition coil. Assuming that they are fitted the same way round in every 1500 - it's the right hand-side connector (to distributor?)that appears to be the source

I videoed it - but the video is taking HOURS to upload to Youtube.

Prop - I can assure you that I have an exceptionally colourful vocabulary (I drive an MGF, and was brought up around working dogs and horses!!)Just haven't had the need to to exercise it just yet - the Midget is so much easier to work on than the F!
Ally

Nigel - its a teeny little spark - not nearly as exciting as the fuel line sparking last weekend, or the horn button spark/smoke!!

Ally

That could be ither wire...neg or pos. Can you see the markings on the coil next to the post it will say + / - or cb / sw

Nigel...the sparks are minimal...with the bonnet up and no pools of fuel giving of vapor in a closed room....i cant imagine there being an issue

Prop

Ally....ah i understand now. Arie is a little sensitve ...hahaha

Thats nice of you to be considerate

Prop
Prop

I'm not a fan of stray electic, messing with the battery, starter motor and solonoid can get you much fatter sparks though

switch smoke can look worse than it is but the horn carries a bit of power

I know so little about the model I've got let alone the more sophisticated 1500s - if I understand you that might be the wire back to the rev counter(?) - whatever it shouldn't spark no matter how teeny

of course the Driver's Handbook will have a wiring diagrapm for you to follow :)
N Atkins

Btw... Is the wire just loose and rattling around on the post



.
Prop

ETA: Prop this engine bay may not be protected with Rhino rubber lining :)
N Atkins

You do have a valid point nigel.... Im assuming the the selinoid is the same as my 71 usa midget....so ally needs to be certian before flinging jumper wires about

Prop
Prop

I can;t see any markings - but to be fair, I didn't think to look. Will investigate tomorrow.

I pulled both wires off and shoved them back on again. They didn't feel particularly loose - but I don't have an ideal to match them against!

Also heard a sort of sucky/slurpy noise when I turned him off. Beastly Child pointed in the general direction of the carbs when I asked him where it came from. Is this normal?
Ally

there will be markings on the coil near the posts but difficult to see

if the spade connectors are tight then it may be the wires in or to the spade

carb noise could be they're out of tune or possibly the fuel bowls or that pump or fuel pipe to/from pump, bowls, carbs

setting carbs up is in that Driver's Handbook too, there's a lot of necessary and useful info in those books :)

IIRC you have a copy so just to remind others :)
N Atkins

LOL...you have to love the rhinno...its some great stuff

Seriously... You do have a point... I had to run extra ground wires to help make my engine electrics work better

Prop
Prop

A sucky / slurpy noise....

Swing for the fences boys....LOL

Perhaps coolant draining back...???

Prop
Prop

what you replaced metal panels with rubber you were dedicated to your cause

rubber hold water well too :)
N Atkins

I've got over the fear of messing with engine bits, but electrics scare me a bit. Guess I'll just have to get my rubber underpants on and get on with it!

Wouldn't surprise me in the slghtest if the carbs were out of tune - it would surprise me more if they weren't.

It was an excellent noise - reminded me of my misspent youth drinking champagne out of the bottle with a straw!
Ally

>>reminded me of my misspent youth drinking champagne out of the bottle with a straw!<<

I've no idea about that - were you too young or rich for Babysham then, cider? in the little green bottle with a baby deer? on the label - I only once bought a girl a brandy? and Babysham when realised the cost, two drinks in one!!
N Atkins

I was tall and skinny and blonde - never had a problem convincing rich young landowners to buy bubbly!
How the mighty are fallen eh!

Babycham was a bit before my time ;-)
Ally

luckily I found/find champers to be much over-rated until recent years I didn't like the taste, cheaper to have a glass of light sparkling cider anyway :)

not that I really drink either

when young my mate would expect the girls to buy him the drink, and they did or he'd walk away and look for another - how was that for equality, ahead of his time
N Atkins

Impressive!! Looking back, my teenage self was a bit of a madam - but it worked!! Now that I'm older, fatter and have a social conscience, I have to fall back on a combination of humour and roast lamb cooking skill to bring all the boys to the yard!
Ally

now that sounds like a good combo
N Atkins

Roast lamb?

Ally, sounds like a good additive for your midget-shower, ill bring mayonaise and Nigel can bring Babycham. :)
Arie de Best

Babycham has left group
N Atkins

What a good idea Arie. Maybe bribing people with food will persuade them to come and fiddle!

Mayonnaise though - that's so wrong! Mint sauce FTW

Ally

Don't eat all that before I arrive!

Back to the subject:
If you can hear the sparking, then it is high tension from the coil secondary jumping to what it sees as an earth. In this case, that's one of the LT terminals. This is caused by running or trying to run the engine with one or more HT leads effectively not connected to design earth, which is a plug gap. Could be HT leads disconnected or broken conductor, extremely wide plug gaps, etc. Coil to dist HT is prime suspect (or you've left the rotor out!). It MAY still be jumping down the outside of the coil HT tower, but it will carbonise a track and/or eventually perforate through the coil HT plastic. You probably now need a coil, but you must first fix the original problem, and NEVER test spark by seeing "how far it will jump", as this initiates the failure. Such tests should be limited to 1/4" or so. It is possible that the original problem has been fixed in the past, but the coil damage remains.

FRM
FR Millmore

Ally,
Earlier you mentioned taht the old fuel pipe was sparking under the car. I suggested the engine was earthing through the pipe in the absence or a fault with the proper earth strap. Did you check this out. Is there a proper earth strap fitted? The spark noise could be the engine finding another route to earth since you have deprived it of the fuel pipe!
Guy

Vid uploaded - I had to watch it a couple of times before I saw the spark - it's a bit blink and you'll miss it.

http://s277.photobucket.com/albums/kk64/allygau/?action=view¤t=VIDEO0006.mp4

Ally

Guy, I have to admit that I completely forgot! I had written it down on my "Things to check" list - but left that on my desk at work,
Ally

Ally if you're around tomorrow morning I was going to bring that door over... will phone first...
David Smith

the starter motor made me jump in that video!

looks like FRM has got it again

I thought earth leads had been covered before, regardless of whether it's causing any problems with things now the engine earth strap could in the future cause problems or not help if it's not in good condition

personally I don't like the braided type prefering the multi-core insulated type

good condition battery, battery connections, battery leads, earths, starter connections and so on will be needed for good starting and problem solving on starting and electrical faults for the future

otherwise the battery going flat during starting or problem solving or car not starting because of low battery or poor connections will hide or hinder or be the cause of potential future problems or problem solving

I've got myself in a loop, I'm stopping now

N Atkins

FRM makes perfect sense to me - have a;ready printed out his wise words! Thank you

Nigel - I guess this is the process of getting the old boy back on the road. Working out what's knackered and replacing it. Kicking myself for forgetting to check earth strap - tomorrow mornings job!!
Ally

Quick Q?
David has just been over, and we've had a little play with Fidget. I thought I was being dense, not being able to spot the earth strap, but he couldn't see it either. It would appear that there isn't one - or it's incredibly well hidden. Could anyone with a 1500 tell me where the earth strap is supposed to be?
Ally

>>Should really be one on the gearbox and one on the engine, engine one is usually on the front engine mount and gearbox one tends to be on the gearbox to engine flange.

As with all classics though they could be anywhere.

If you haven't got one at all I guess you have a sluggish starter and a hot choke cable!<< Oliver Wild


>>Found it, or at least one of them, in the vicinity of the O/s engine mount<< stedale

>>Look at the condition of the bracket where the solenoid is mounted, rust under the mounting screws can cause serious problems even if all the other power cables are healthy

The solenoid switches the main starter power on by earthing the magnetic pull down coil through its mounting bracket


It's worth taking it off again and cleaning the (probably) rusty metal where it mounts with emery cloth/sand paper then covering with a thin film of Vaseline before refitting it. Wouldn't hurt to touch up the surrounding area where you sanded it with a drop of zinc primer then a cover up (for tidiness!) of topcoat colour

The Vaseline will do a fine job of arresting further rust growth for a while<< our own Bill
N Atkins

the starter turns the engine over pretty well, that's not a problem. We just want to know where the earth strap was fitted by the factory, they didn't just randomly put them anywhere! And of course it has two ends so knowing both end locations would help us find it too (or put one back how it should be).
David Smith

It sounds like you found the problem...no strap....its NOT hard to see

They are located at the engine / transmission union and bolt to the cross bar a few inches away....it will be about 1/2 inch in diameter and braided strands of bare strands of silver wire. It will be easily visable from under the car... I think they are in the same location as the 1275....your drivers side but i dont know that for certian as to its location

Based on your past postings....i dont think you have one

I can take a photo of mine for you in a few hours

Prop
Prop

OPPss ... I was wrong on the 1500s location...i just did a google image search and the photos show it at the front of the car ... UK drivers side at the engine mount and goes to somewhere near the crank shaft pulley...but its the same braided wire

I cant get the photos to transfer from google to the bbs ...but i just went to google, clicked images... Then typed "mg midget earth strap"...and got about 3 images of the strap and its location

So no photo from me as mine is a 1275 and a differant location

I hope that helps

Prop
Prop

David

>>Should really be one on the gearbox and one on the engine,

engine one is usually on the front engine mount

and gearbox one tends to be on the gearbox to engine flange.<< Oliver Wild

>>Found it, or at least one of them, in the vicinity of the O/s engine mount<< stedale

what more do you want !?!
N Atkins

Nigel, just a clear unambiguous factual answer.
'should really be' sounds like a recommendation (whose?)
'on the front engine mount' - not much help as (a) there are two mounts, and (b) where does the other end go?
'gearbox one tends to be...' - they didn't build them with happenstance or randomness; where did the factory install it, and where does the other end attach to?
David Smith

Normally earth straps physically just bridge the rubber part of the mount, from one side to the other. Commonly are attached to the same bolts that hold the mount on.

Guess what? That is also their electrical function - to complete the earth circuit that has been interrupted by the non conductive rubber bit.

Thus it will usually be across one of the rubber mounts, but it could easily be from any metal point on the chassis to any metal point on the engine/gbx. Early Spridget was from the frame to one of the slave cylinder bolts; I don't remember 1500 location.

For complete clarity, and best electrical performance, I like to run the battery earth cable direct to the engine at a solid point, usually the bell housing near the starter, since that is the heaviest c200Amp load. Then the standard earth strap only carries the smaller c20-30Amp total loads of the actual car electrics. Some modern battery cables have a secondary power feed wire built in to the cable; you can run the main cable to the bell housing, and the secondary to the usual body earth on the firewall, thereby doing away with the original earth strap.

FRM
FR Millmore

in the absents of anyone reply I thought I'd helped - I've never owned a 1500 so can't say from experience

OK lets pick the bones out -
on a PH thread titled - Midget 1500 earth cable the OP, named stedale asked 'Where should this be found'

wildoilver, who seems to known about MGs from all his posts put 'Should really be one on the gearbox and one on the engine, engine one is usually on the front engine mount and gearbox one tends to be on the gearbox to engine flange.

As with all classics though they could be anywhere'

stedale replies 'Found it, or at least one of them, in the vicinity of the O/s engine mount'

by now most cars are NOT as they left the factory hence by experience Oliver has put 'should be'

he also put 'front engine mount' and stedale found his near the off-side engine mount (this is on the r/h/s as you look at the car from the rear so on the left when looking from the front)

I don't have a 1500 so I'm going to assume the gearbox earth strap - if it's still fitted - will go from the gearbox to the body

I would guess you'll need a torch and be able to get under the car to perhaps see these

I also included Bill's advice as that is perhaps the next stage, it may not be relevant now but could be very relevant soon - many thread are about engine not starting or poor starting
Nigel Atkins

I mentioned on Aly's other thread where the strap should be located. My 1500 had the earth strap in much the same position as my curent 1275. That is, connecting from the front engine plate to the chassis, the chassis end being clamped with one of the mounting bolts for the radiator cross pipe just behind the rack. Can be a bit hidden by the rack pinion/ steering column (UK cars)

My car only had the one strap, if it was supposed to have one at the bell housing then it was long gone when I had it. Some 1500s (N American export cars I believe) have another sort of "cable" attached to the gearbox but that is a safety cable, not an earth strap. Supposed to tame the gearbox in the event of a major accident.
Guy

sorry I was still typing whilst FRM posted

I like FRM's idea of lead to engine and secont to firewall

my 1275 has engine earth strap (IIRC) bell housing to body and battery earth lead to roof of footwell and not firewall - not as the factory intended but as it was at my purchase

never assume that anything on the car is the correct part or component or fitted correctly or as original

there can be upgrades or parts fitted in an alternative way that work - or wrong parts or items not fitted correctly that don't work so well
Nigel Atkins

There are certainly plenty of things under Fidgets bonnet that have been changed/amended/improvised/bodged (delete as applicable!)

Many thanks to all for input, and especially to David for coming over and poking around under the bonnet. Him saying that it looked to be a solid, clean little thing gave me fresh hope!! Ir's so close to running that I can taste it!!
Ally

FRM - early Spridgets (& 1275s) rear earth strap was not from a slave cyl bolt, but from the o/s bolt on the exhaust mount bracket which is attached to the bottom edge of the backplate.
Nigel - I know many cars are not as they left the factory, I asked the question precisely because I want to fit an earth strap as the factory did, not perpetuate somebody else's bodge or non-standard installation.
Guy - thanks very much, that's what I wanted.
Ally - next weekend, elle va!
David Smith

David,
I apologise for not fully understanding what you wanted I'd got used to Ally's more relaxed style :)

I'm not sure that they didn't sometimes build them with happenstance or randomness on some parts of the production on some occassions :)

it is possible to improve on some of the factory installations :)

I still like FRM's idea of an earth lead from battery to near starter
Nigel Atkins

This thread was discussed between 19/11/2011 and 21/11/2011

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