The winner of week 5 is….

                                      Mike Woodward!

Why Do I Have Such Poor Acceleration?

Corona Competitionentry, week 5

By Mike Woodward

Several years ago I sold my MGTD trailer queen and replaced it with my current 1980 MGBLE, which was and is a driver’s car as opposed to a concours car. Upon opening the bonnet (‘hood’ for you Colonials), I noticed that the distributor body was damaged and that one of the clips that is supposed to hold the distributor cap in place was missing. An enterprising previous owner had solved this problem with a bungee cord! Not wanting to have my driver’s car stranded on the side of the road with a failed bungee cord, I elected to replace the distributor with a complete brand new distributor from Pertronix.

I installed the new distributor and then set the timing at idle, per the book, with my conventional timing light; turned the key, and it started right up and idled perfectly. I then proceeded to drive the car all over Texas and it ran smoothly with no obvious problems.

Three years later, with the help of club member Dwight Dawson, I went to Weatherford, Texas to trailer home (dare I say) a 1979 Triumph Spitfire that was in need of some serious TLC. Several months after that, the Triumph was ready for the road and so I took it for a spin. I noticed immediately that this car accelerated far quicker than the MGBLE, despite only having a 1500cc engine instead of the 1800 cc in the MG. It appeared something may not be quite right with the MG.

A couple of weeks later I attended a tech session put on by club member Ron Redding. On the way to Ron’s shop I was following six other MGBs, all of whom left me in the dust. Something was definitely wrong with my MGB!!!

I started to check what could be the cause of the problem and noticed that when the engine speed increased, the ignition timing did not alter. I realized that for 3-1/2 years I had been driving a car with a non-functioning centrifugal advance mechanism in the distributor. By this time the warranty on the Pertronix was well out of date. I elected to buy a used 25D distributor on eBay and install an Accuspark electronic module in it, thereby having the reliability of modern electronics but for a total parts cost of $65 instead of the $200 I had paid for the Pertronix.

Next came the question as to whether the centrifugal advance on the replacement unit was working, and also what amount of advance I was getting at full engine speed. Enter the setback timing light, which is now in the arsenal of the HMGCC loaner tool program and is pictured here.

I am happy to report that the MG now out-accelerates my Spitfire, albeit only by 0.5 seconds in the run up from 0-60 mph!