6 replies to this topic

[83sprite]

Hey everyone ive jst recently swapped my 998cc engine out my 1983 mini sprite with a 1275cc engine from a 1991 cooper. The engine is using electronic igniton and has a stage one kit. At the moment the engine is running rough, it seems to be running on 2 cylinders and it is idling way to high around 1500-2000rpm. I think the idle issue is due to either the idle screw being too mch adjusted or the choke cable which seems to be loose. How ever the mis firing i do not understand, there is spark at the ends of every ht lead and the spark plugs are working, does anyone have some suggestions, they would be much appreciated.

Regards
Steve

[minimender]

Hey everyone ive jst recently swapped my 998cc engine out my 1983 mini sprite with a 1275cc engine from a 1991 cooper. The engine is using electronic igniton and has a stage one kit. At the moment the engine is running rough, it seems to be running on 2 cylinders and it is idling way to high around 1500-2000rpm. I think the idle issue is due to either the idle screw being too mch adjusted or the choke cable which seems to be loose. How ever the mis firing i do not understand, there is spark at the ends of every ht lead and the spark plugs are working, does anyone have some suggestions, they would be much appreciated.

Regards
Steve

First check that the plug leads are on the right way. 1 3 4 2 anti clock on dizzy.

[olds_kool_lews]

are all the sparks relatively the same strength? i put a 1275 engine in my mini the other day, and it seemed to be running on only 2 cylinders! so i changed the dizzy cap, ht leads and rotor arm, and its perfect now! had me scratchin my head until i checked the sparks, had sparks to all cylinders, but as the cap was corroded, and the rotor arm was worn, it didnt always make contact, so caused misfire!

hope this helps

[minisilverbullet]

my bad thought it was an spi!

Edited by minisilverbullet, 10 February 2010 - 11:36 AM.

[83sprite]

are all the sparks relatively the same strength? i put a 1275 engine in my mini the other day, and it seemed to be running on only 2 cylinders! so i changed the dizzy cap, ht leads and rotor arm, and its perfect now! had me scratchin my head until i checked the sparks, had sparks to all cylinders, but as the cap was corroded, and the rotor arm was worn, it didnt always make contact, so caused misfire!

yes ive checked the spark strenghts and them seem to be the same but week. The symptoms you describe seem to be spot on, i work at an audi dealership and have had 2 fellow technicians helping me today and we are struggling to solve it. My dizzy cap and rotor arm were corroded so i cleaned them as best i could, i am interested to know if your engine was just seeming to be mis firing on two cylinders on idle because mine does that but seems to drive fine, it revs and pulls well which is why im stuck.

Regards
Steve

[Big_Adam]

My dizzy cap and rotor arm were corroded so i cleaned them as best i could

Dude, spend £20 and service your engine.

[lawnmowercrap]

Obviously check that you have got your firing order correct for a start and that you are running the correct coil. I.E ballast or non ballast.
Make sure that your wiring matches up with that engines coil etc.


Seeing as you work at an Audi dealer I assume you have a timing light and an emissions machine.

Change your dizzy cap, rotor arm, HT leads and plugs. Put NGK's in from halfords.

Get it running and use the timing light to adust the timing to 12 degrees BTDC at 1500 rpm. (Vac advance on)

When you've done that adjust your idle to 1100rpm (hoping your running a HIF44 as these are better to set up than a HS4)

When thats done, hook the emissions machine up and ram the probe up and set it to between 3.5% and 4.5% CO. I always do it to 4%

When thats done, adjust your idle again if you need to. Check your mixture again. Then road test it.

Edited by lawnmowercrap, 09 February 2010 - 11:49 PM.