BlackIce comes to the aid of TR owners, helping to solve a ‘known’ issue:

After mods to the induction system and exhaust system in my TR, I noticed that a few of the minor niggling habits of the engine and gearbox had gotten worse. These included:

• Over rich mixture smell from exhaust
• Rough idling
• Stalling often especially when hot
• Failed A/C motor (wouldn’t idle properly with A/C turned on , after hard braking or with steering on locked )
• Shuddering from front when accelerating out of corners
• Sluggish performance down in the rev range
• Annoying flat spots between 700 & 1000 RPM and 2700 & 2900RPM

Running Premium Unleaded in the car was a stop gate measure that stopped the stalling and rough idle problems, but not the others. I had come to blame a failed A/C motor and need of auto-gearbox service for the other problems, and engine timing for the flatspots. When I took the car in to have the timing checked the cause of all these problems was found (three kilometers out of town when the engine gave up the ghost on a demo run). The problem? A corroded distributor plug!

If you look down at the distributor (the black thing with the spark plug leads coming out of it) on top is cables going into a black plug. The plug also has a silver spring clip so its easy to identify. On the back of the plug is a rubber seal covering it and the cables running into it. This rubber seal is there to prevent water or dirt getting into the plug and fouling the connectors. Problem is 10 years of engine heat, water, oil and all sorts of corrosives had eaten the rubber away, letting water, dirt and engine bay muck get into the plug. The terminals then corroded and caused breaks in contact stopping the electricity flow. This explained why in certain situations (such as cornering) the engine would shudder. The Mitsubishi mechanic told me that the four wires going in controlled ignition and information feeds for the engine computer. The connection for ignition triggering was intermittent (causing the shudders, rough idle, etc), while the connection for the A/C cable was broken (hence it failed). The timing problems, I was told, were also most likely caused by the bad connection.

To test if the plug is playing up, with the engine idling grab the cables going into the plug close to it and jiggle them around. If the engine splutters, stalls or the idle speed changes, you probably have a problem with a corroded plug. If the rubber protector is perished or has holes in it, you should also clean the plug.

Cleaning the plug:

What you’ll need:

• Mentholated spirits
• Old toothbrush
• Small flat jeweller’s screwdriver
• Fine grit emery board (or sand paper)

What to do:

1. Push the spring clip towards the plug
2. Pull the plug off the distributor
3. Dip the toothbrush in metho and scrub the inside of the plug and the distributor side
4. With the emery board, GENTLY scrub the sides of the tounges in the distributor side plug. You only want to knock off any left over muck that the toothbrush missed so don’t go overboard
5. With the small flat jeweller’s screwdriver, gently scrape the inside edges of the grooves.
6. You should also use the small screwdriver to bend the sides of the grooves close together, so that they firmly contact the tongues when re-attached to the distributor.
7. Make sure all the metho has dried out completely (electricity + metho = fire, so be double sure), then clip the plug back onto the distributor. It will make a clicking noise when in place.

Now kick the car over and check the plug again. If it still plays up there are some possible reasons:

• The tongue/groove connection isn’t secure (pop the plug off and make sure the gap is closed)
• The corrosion has eaten away too much metal and the plug needs replacing
• The cables need replacing

Please be careful doing this. If you are too rough with the connectors in the plug or on the distributor you can break them, resulting in costly repairs (the plug is $60 ! $40 trade price). And ensure the metho is dry before plugging back in or starting the engine (remember, fire bad). Please see a qualified mechanic if problems persist.

I do not accept responsibility for any damage you to do yourself or your car after reading these tips. Please use your common sense when tinkering with your vehicle. If in doubt, consult a certified mechanic.