Welcome to our resource for MG Car Information.
MG Midget and Sprite Technical - 1500 Misfire Fixed
|Pretty much since I got the midget running, it has been suffering from a slight misfire, most obvious at low RPM.|
Whenever the misfire occurred the tachometer needle would flicker (suggesting a LT problem).
It has been getting progressively worse, and over the weekend the car occasionally wouldn't idle.
Finally found the cause, really a testament to the quality of parts these days.
The contact on the moving side of the points is just floating within its mount, no idea how it managed to run quite as well as it was!
Check out a video of it here:
|I don't think many on here will be surprised about the poor quality|
again shows there problems are often very basic
I know some like to mess around with points but personally I got my classics on to electronic heads (or dissy now) as soon as possible
when you replace remember to lub the cam and a drop of oil in the dissy if not done at regular services
I do intend on fitting an electronic ignition, but wanted to sort this out before!
|Hi Josh, well done on finding it and letting others know|
easy for me to say not working on the car and with hindsight but it did confirm the check the basics on these tricky problems, although things like this are not easy to see, it also covered the check new (well newr or not original) parts
if you can afford it I can recommend going fully electronic and replacing a possibly worn dissy by installing the 123 dissy
if you do this just after a full service where you've adjusted the tappets then you can set the timing and carbs and sarting, idle and running will be better and more constant
if you could then or later get it up to Peter Burgess for a RR set up the car will be a lot nearer to its full potential
|Good sleuthing, Josh! Nice to hear you got it sorted. I'll chime in with a recommendation to ditch the points and condenser. I have a Mallory diz, originally dual-point but now fitted with a pertronix. Hasn't missed a beat in years!|
cheap as chips and it works!
ditch those points and condenser.
123 is nice but has some down sides too (besides the price)
All the conversions with external boxes are obsolete to difficult and way to expensive!
|Thank you for the electronic conversion recommendations.|
The only thing from stopping me from doing this is my coil.
It is a new coil, recently purchased for a ballasted ignition, it should be 1.5ohms (just high enough impedance for the electronic ignition), but is actually 1ohm.
Hopefully the supplier can swap it for me!
This thread was discussed on 01/08/2011
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.