Loss of power / surging?

[panky]

Here's a picture of the lifting pin if you're still struggling to find it.[frame][/frame]

[nwxh]

Thanks, but following the advice to lift off the cover (wish I'd thought of that before), I've discovered it's missing. I assume it can't just drop out the bottom and so someone has probably lost it while working on it.

This probably explains why I found the mixture get a lot leaner with high acceleration. As BMC pointed out, it's killing my idle.

[katy]

Are you sure that the readings are PSI? I see 2 scales on that gauge.

[bmcecosse]

I did ask that - but even if it is 'Bar' - then ~ 5 Bar only equals ~ 75 psi.......still dreadful.... it should be ~ 10 bar...

[nwxh]

Indeed, all I can think of is that what I put into the spark plug sockets was narrower and I should have used the longer adapter. However, all three threads seemed to be the same.

Today I had a terrible ride, made some adjustments, got it slightly better, and then some extra adjustments and it was smoother to the point I ended up driving too quickly because of the smoothness. The exception, is lower revs, which I assume is the lifting pin. Actually I think I'm still running rich at higher revs.

[bmcecosse]

You need to plug off the hole....

[nwxh]

Will duct tape do? Cheers

New lifting pin (I hope) coming in the post.

[bmcecosse]

No...

[nwxh]

Probably have to wait for the real part then. Cheers!

[bmcecosse]

Matchstick...

[nwxh]

Thanks again for the help.

Compression Test
With new tester http://www.amazon.co.uk/Draper-37442-Co ... ion+tester which actually works.

Dry / psi
150 155 150 160

Wet / psi
160 165 160 160

Carb
I rebuilt the carb (perhaps OTT). There is a missing washer in the SU picture (not in the Haynes manual) on the throttle pin, leading to some movement. It turns out the hole for the lifting pin had already been blocked, but it appears by metal! Should I redrill it next time I take it out?

Vacc advance cable was replaced just in case.

Fuel line
This is replaced.

Results
[*]The car is still making a sound at low throttles which I thought was pinking, but it can't be because retarding the engine makes no difference (I just lose power).
[*] I think I'll have to reuse the colourtune as the only way to pull up the piston seems to be pulling out the dashpot plunger....

ps

[*]Had to replace the choke cable as the other one was frayed. This proved awkward to get access to, and took a few hours. Lowlights included having to rewire the headlight/sidelight by trial and error.
[*]Turns out the panel switch has been rewired as an anti-theft device on the ignition. At some point I will rewire it out just in case.

[panky]

If the engine is running very weak this could cause pinking too. Turn the mixture nut anti-clockwise a turn and see if it makes any difference, if not try another turn - you can always screw it back if it doesn't.

[nwxh]

Thanks for the suggestion. However, pulling the choke out must have the same affect as at least three turns, right? This made no difference, and I've tried it a few times.

Also hills make no difference to this issue and running up hills at high throttle makes so difference. I can rules out the vacc advance now.

So all I can think of is, engine trouble (but this would show in low compression right?), the loose throttle due to said washer issue (but the sound seems to be coming from further right) or that this is just a sound that the A series always makes which sounds like pinking but isn't.

[panky]

Give the mixture alteration a try, when setting up my new carb I was surprised how many turns I needed to turn the nut out. It was hunting horribly and back-firing until I got drastic with the mixture.

[dalebrignall]

i would say the compression figures are ok , bmc is the man to ask

[bmcecosse]

Yes - they are fine. You can lift the piston with a thin blade screwdriver. Keep advancing till you DO get pinking on a hill - and then turn it back v slightly so it's 'not quite' pinking. It's perfect then! Take the car for a good run - switch off and drift to a halt (obviously take care where....a layby would be best) and pop the plugs out to see what colour they are. You're looking for 'beige'...

[nwxh]

Thanks!

The flat blade screwdriver goes up by the jet then?

Should I ignore the thing which seems to be "pinking" but isn't? The engine performs better when it's more advanced up to the point it's clearly pinking under load as you suggest.

[bmcecosse]

You simply insert the screwdriver at the inlet - obviously the air cleaner has to be temporarily removed... But no matter - the important thing is the running mixture - as shown by the plug colour..

[nwxh]

Thanks. Got a 120 mile round trip coming up, so that'll help.

So should I ignore the "fake pinking" sound that occurs no matter how retarded the dizzy is?

[bmcecosse]

I guess so ! It's pinking under load that causes harm (and therefore has to be avoided) - you sure you're not just hearing timing chain rattle ?? Check the crank pulley - they have been known to 'crack up' and cause odd noises before they finally disintegrate....