7 replies to this topic

[mgfreak79]

ive had to start a new topic as i couldnt edit the other one sorry everybody!!!!!!


My next problem and bigger one is the timing, from what i can gather it should be running at around 8 deg tdc. When i set the timing to this it miss fires, however when i turn the distributor clockwise to about 20 deg before tdc it runs well but it's just flat in third and fourth at around 50 onwards.

Somebody said this can be down to low compression, so the timing very retarded


does anyone have any ideas, as i do not really want to take the head off again to skim it


thatnkyou very much. im amazed at how friendly and knowledgable people are on this forum.

[jaydee]

Are you setting static timing or using the strobo light?
Are you able to advance timing turning dizzy clockwise to a point where revs stall then go back a couple of degrees?
About compression, as i said in the other post, best measure chambers..

[Guess-Works.com]

All timings are BEFORE tdc so that's a good start, 8 - 12 degress btdc at idle will get most cars started, but ideally you need to find the correct figures for your engine... Also make sure the vac pipe is disconnected from the dizzy when tming.

Once you have it running, then you need to do a few test runs with the car under load ( 3rd uphill is good ) and listen for the pinking, advance the timing until you hear it pink, and then back it off a degree or two...

Then sort out the fueling, as now you've changed the timing, that will probably also need changing... and then it's an iterative process of changing one then the other until it's spot on..

The alternative is take it to a rolling road where it can be tuned while the engine is under load ( the ideal settings )

[mgfreak79]

Right im half way there now!!!

Thankyou again for the relpys its great to bounce ideas of people and see what they think ium doing wrong and everything

with the vac pipe disconnected, it was connected when i was trying it!!! (imbarresing really i have done all of the correctly in the past but sincre being on all the modern stuff plug in anf fit!!! no thinking involved!) my brains switched off!!!)im running at about 10 which is almost there for my engine its a little lumpy but now i assume its down to mixture what the basic setting so to speak wheres a good place to start how many flats of the mixture screws what should i be checking for! hunting pinking ect whats the diffrence?

The mini is going for a pro tune up at sleaford mini centre but i want to get it there and save a bit of money making sure everythings almost there and nothings ovb out! ive now bit the bullet and just bought a k+n panel filter purley to dump the standard air box and making adjustments easier!


Thankyou again!!

Edited by mgfreak79, 20 January 2010 - 07:01 PM.

[Guess-Works.com]

basic setting on all SU carbs is two turns on the screw ( whether it's an HS of HIF ) from the jet being flat level with the venturi in the carb.

[bmcecosse]

Just get the engine running - then do as suggested above -advance it till it pinks, then back it off very slightly. But if the vacuum advance is faulty - or the mechanical advance inside the dizzy isn't working properly - it won't run well. So - check them out! Most vacuum units over 10 years old will have failed - suck the pipe and watch to see if the dizzy base plate moves. If you can't suck a vacuum then the diaphragm is burst - and if the base plate doesn't move - then it's seized up! To test mechanical - twist the rotor arm - it should spring back.

[mgfreak79]

Just get the engine running - then do as suggested above -advance it till it pinks, then back it off very slightly. But if the vacuum advance is faulty - or the mechanical advance inside the dizzy isn't working properly - it won't run well. So - check them out! Most vacuum units over 10 years old will have failed - suck the pipe and watch to see if the dizzy base plate moves. If you can't suck a vacuum then the diaphragm is burst - and if the base plate doesn't move - then it's seized up! To test mechanical - twist the rotor arm - it should spring back.

The vac unit in the dizzle is fine it was broken about a year ago but was replaced for new just tested it agian and its not that thats fine

But thankyou i think its just down to fuel and fine tuning

Whats pinking and hunting ect ect ?

[bmcecosse]

Pinking = rattling/tinkling noise heard as the fuel detonates due to over advanced ignition! Very damaging - must NOT be allowed to continue. Only happens when engine working hard - hence test it uphill in 3rd gear - foot well down! Advance little by little till you hear it - then retard v slightly.