7 replies to this topic

[PaddyShepherd]

Lately my mini has started getting serious judders/loss of power around the 2k mark, then smoothening out...

More so when the engine is cold, so I think it could have something to do with the fuelling/carb...

It's not all the time, very temperamental. It'll accelerate up to between 1.5 to 2k revs, then it'll kinda judder about, lose power, gain power, lose it, gain it a few times then fly off and will be fine for the rest of the rev range! I've been told it could be something to do with the slow running jet on the carb? or something along those lines. I'm gonna get the carb off for a good clean up whenever I get time anyways, but that's not going to be at least the weekend now. It really shakes the car about when it does it, and I've checked the engine mounts and they seem fine, I can't move the engine by much if I get hold of it and try to rock it, so the steadies seem fine. It starts fine even on the coldest of mornings (with the choke of course) and has no problem through the rev range, only under load, does that mean that it could be the coil?

Apologies if this has been asked before, I did try a search but couldn't find much I'm afraid.

[PaddyShepherd]

anyone?

[jaydee]

Check the vacuum pipe from carb to dizzy is connected and theres no air leak at the manifold.
Also, do you have a timing gun?

[PaddyShepherd]

I don't I'm afraid, have you got a pic showing the location of that pipe? I've just checked my dashpot oil as well and that was quite low so I've topped that back up to see if it improves.

[PaddyShepherd]

I wouldn't have thought it would be the timing, as it came on quite suddenly to be honest, and i've never had problems with the timing before. I'll see how the dashpot oil affects it as it's been mentioned to me. I'll report back tomorrow.

[jaydee]

The should be a little plastic pipe connecting these two parts:

Little mushroom on the carb:


Vacuum take off on the dizzy:



If these two parts are not connected you wont have the correct amount of advance when passing from under load conditions to cruising speed and vice versa, casuing a judder due to incorrect fuel combustion.

Thats my first tought as 2000rpm is a critical point in most advance curves.

[jaydee]

No oil in the dashpot cause a similar issue at pick up but from any revs..

[PaddyShepherd]

It did seem to do it when I first put the throttle on to pick up, when i was out driving but it was very rare, but more common in the lower revs. I forgot to mention that in my above post. So maybe it is just the dashpot oil. I've filled it back up now, just put about 1/3rd to a 1/2 of a cap full of oil into it and it felt much better putting the cap back on. Barely any resistance at all before. Thanks for the photos, I will check that when I've got time if the dashpot oil does not help.