7 replies to this topic

[Tommyboy12]

Hey guys. As title says ive basically its got a misfire at high RPM and the car feels down on power. It was rolling roaded in the august and was running perfectly. Then when it snowed it killed my dizzy so i had a whole new one put in. It ran fine again although i think the timing may have been slightly out. It then broke down again with what i believe to be a wet dizzy. I let it dry out naturally and its had a misfire since. Im convinced its an ignition fault of some sort. Ive replaced the cap, HT leads and plugs since but to no avail. Apart from the coil is there anything else it could be? All i can think is that ive damaged the points or condensor but i dont know the symptons of this.
Any help on this would be appreciated before i go out and buy new points, condensor and coil when i may not need them.

Also my old plugs were quite black but not what id call oily. Is this a sign of uncombusted fuel from my misfire or something worse? Im not sure on the age of the engine but ive been told by a garage that its in good health although its burning a bit of oil as it has a light blue haze to the exhaust fumes.

Engine is a 1275cc from a metro running a 45D dizzy and a ballast coil.

[Tommyboy12]

Heres the plugs incase that helps anyone...

Attached Files

•  SDC11577.JPG   4.11MB   14 downloads

[bardan]

Are the points pitted or shinny at the contact surface? If pitted, use a small file to clean. The wire that goes from the movable point to the condenser may be chaffed or cracked. Also you said high RPM, could it be point float? If the points are set too wide or the spring is old, high RPM can can cause the points to "skip" accross the cam.

[Bungle]

i had a similar problem as few years ago i couldn't trace

went on a club rolling road meet and the operator traced it to the coil, i replace it later and he was right miss fire disappeared

[Tommyboy12]

I dont have a tacho but by high RPM id say over around 3k. Ill check the points and condensor tomorrow. If they look ok ill try replacing the coil before i go any further with them. Is a standard ballast coil good enough? I want a decent spark but i dont think my engine is tuned enough (81bhp) for a 'racing' coil.

[bardan]

All a "racing " coil means is higher voltage. Two problems can occur with them; 1. high voltage will find it's way to ground through small or poorly insulated plug and coil wires, minor cracks in the dizzy cap or accross dirty spark plug insulators. 2. Static to your radio. If you put one on, watch the engine run on a dark night and look for arcing.

Edited by bardan, 12 January 2011 - 07:26 PM.

[Tommyboy12]

Ill stick to a boggo coil then. Nottingham Mini Bits do a Wipac unit for less than a tenner!

[bmcecosse]

Rotor arm - points not set correctly - timing not optimised - vacuum advance not working ??? Plugs look rich if taken out after a hard run ?