rather slow moggy

[onion]

Trudy's having a bit of trouble getting any speed up. That is to say, she wont go above 45mph down hill, 40 on the flat.

I was told it might be the timing, so I've set the dwell angle to 60˚ and adjusted the dizzy till it sounds fastest/smoothest. but still no joy.

Any other ideas, or is it the engine itself?

(P.S. its a 948 engine)

[autolycus]

I think we need a bit more detail to save having to write pages of irrelevant basic diagnosis stuff.

Did this suddenly happen, or has it progressively worsened, or have you only just bought the car? Have you checked or replaced anything yet, apart from the timing? Did you adjust it far? Does it seem to run smoothly, but with reduced power, or is there a regular misfire?

Have you felt the wheels after a run to see if any of them are hot?

Tell us more!

Kevin

[bmcecosse]

Start with the simple things - new air filter, valve gaps reset and then a compression test. Is it really slow - or could it just be a low reading speedo?? I would expect just about any Minor to manage 70 downhill - unless the brakes are dragging ????? Are any of the wheels hot after a run??

[onion]

good idea, i'll try to give you some more details.

Had her for about a month, has never gone above 45. I've tried adjusting the dizzy with the only result being a drop to 35. Haven't replaced anything, only thing I've adjusted is the dizzy and cleaned/gapped the spark plugs (which are an ochre-y colour, so running a bit rich). and it has been running smoothly, but today it went weird (see below)

Haven't tried the wheels, will try taking it for a run tomorrow.

It's not the speedo, I was being overtaken left right and centre (well, mainly right )

Today I had a problem which I reckon is related, I was driving along and it started revving quite high and I heard what sounded like a backfire and lost the engine, looked under the bonnet and the dizzy had popped out. I managed to get it back in and revving at a decent speed (a little slow if anything) by the time I got home (about half a mile) it was revving way to high, and the dizzy hadn't moved. There's also now a 'popping' coming from the air filter when idling which is smoke when I remove the cover, but thats a new thing today.

think thats everything, but if I've forgotten anything, I'll try to supply the details.

[bmcecosse]

The dizzy 'popping out' is a strange thing...... obviously the securing bolts were not tight...... The timing is now probably WELL out...... Start again..... the 'revving' suggests a slipping clutch......... Is there any 'free play' at the clutch pedal?

[onion]

Probably not, i have been adjusting the dizzy quite a bit trying to get the timing, so i might not have done them up fully.

There's about 3" of free play, which, thinking about it, is probably far too much.

[bmcecosse]

Well - no! Clutch slip occurs when there is NO free play..... However - that's not to say that the clutch is NOT slipping - it may be loaded with oil - causing massive slipping. Is there any oil dripping out the jiggle pin hole?

[onion]

I shall have a check in the morning tis too dark to see anything now. what should I do if it is oily?

[bmcecosse]

Just a guide to tell us if the clutch may be slipping.......

[JOWETTJAVELIN]

Revving could also be due to sticking throttle linkage/acc. cable out of adjustment. Check carb and cables. This would also explain the inability to exceed 40, if the acc. cable was or had slipped.

[chickenjohn]

Let's get back to basics, first set the engine to top dead centre (turn it on the starting handle - ignition off!) till the timing marks on the underside of the front plate of the engine point to the notch in the crank pulley. A spot of white paint helps here.
Then loosen distributor by undoing the clamp till the dizzy moves, then rotate the distributor with the cap off till the rotor ram points to where no 1 spark plug contact goes. Then tighten pinch clamp bolt and mounting bolts.

Timing will now be close enough for the engine to start and run.

Then use a timing light to get the timing (engine running at idle) close- white spot illuminated by the strobe should be between the big pointer and the first small pointer (I disagree with BMC on this one- a timing light IS useful at least to get close). Then finally when the timing is close, test drive the car and if it pinks retard the ignition. As the distributor rotor arm moves in an anti clockwise direction then to retard the ignition you move the distributor in an anti clockwise direction by a few degrees each time to retard the ignition. Retard till the engine no longer "pinks" when going up hill under load.

An other cause of 35mph maximum speed could be the points gap being wrong. With the distributor cap off, rotate the engine with starting handle, the points will open when the points heel is moved by the distributor shaft cam, you can then see the gap. Too big a gap and the car will perform poorly. loosen the points screw with the points heel on the cam and move the points back plate till the gap is 0.014-0.016in (feeler gauge)

It would be a good idea to buy a workshop manual which will show you all this and more.

[chickenjohn]

If the engine will still not rev (if it stutters) then the condensor may be faulty. Change it for a new one.

[JOWETTJAVELIN]

If the engine will still not rev (if it stutters) then the condensor may be faulty. Change it for a new one.

A new British one, of course!

[chickenjohn]

Of course Jowett, now that English made condensors are available again.

[onion]

BMC - there's a little oil on the pin, but its not dripping.

Jowett - no sign of the cable slipping, but the spring anchor had come loose, so I've tightened it up.

John - When #1 was TDC rotor arm was closer to 2, and even if i rotated it as far as it would it was still only half way between 2 and 1. I tried moving the cables round 1, but then it wouldn't start at all, so I moved them all back. Idle speed isn't changing itself though, so thats improved.
Also, the gap is 0.015"

I've done a stationary wheel test (daren't go out when my parents are out with the modern car so cant come rescue me ) rear near side brake is dragging a little bit, manages almost full free rotation then drags for the rest.

[bmcecosse]

Doesn't sound like serious brake drag - but you should have a look at it. As hinted above - check if the carb is fully OPEN when your foot is floored on the accelerator.

[onion]

carb is fully open when I floor it.
And I've discovered the speedo may be out, but I don't thing its the main problem (was going through town at just under 30 on the speedo and set one of those warning lights off)

Just a thought, could it be down to a dodgy fuel pump?

[bmcecosse]

Maybe - or perhaps the coil! (Just joking there ). I suppose if the fuel supply was seriously impeded it could be the pump (clean the filter) - but would only expect that to kick in at 70+ mph!

[onion]

You got me worried there

[bmcecosse]

Check the pump delivery by pumping a pint into a container - and report how long that takes....... No smoking!