I finally got a round to trying out the Gunson Colortune I got last October. It wasn’t as difficult as I thought it was going to be with the instructions in clear English and to the point. The most difficult part was putting in the spark inspection plug in, without burning my fingers on the exhaust manifolds.
On the instructions it said you only needed to use one cylinder on a single carburettor and one inlet manifold design as per my V4. It was a simple task of removing a spark plug from any one of the four cylinders and replacing it with the Gunson spark inspection plug. It advised on having a clear view as possible of the plug which would become evident later. As mentioned earlier, the awkward part was fitting the inspection plug with its copper washer as it was quite a lot shorter and stubbier than a spark plug and difficult to get a decent grip with finger tips especially with a warm/hot manifold nearby. A deep 14 mm socket would have been best to tighten the plug but finger tight with a normal socket was good enough. After that, a long thin rod from the set was screwed in place so the HT lead could be connected.
When I got the Corsair back on the Friday (26th July) my main goal was to get it to the local classic and bike show at the Barton Hill Recreation ground, on Sunday. There was an existing problem that I had forgotten about which was the ignition light staying on and glowing brighter with more revs. I spent an hour or so on the Saturday diagnosing it to be a failed alternator. The Barton Hill show wasn’t far, and I sensed the Corsair had enough battery life to at least make it to the show which I had missed for the last 3 years. The show was a peaceful informal affair, with a few people taking an interest in the car.
Earlier, back in May, I got the Corsair to John Midwood’s for some long over due engine work to be carried out, as the oil leaks were getting worse and the nearside cylinder head, rear core plug needed replacing. In readiness, I had got new core plugs and crankshaft seals (front and rear) on eBay, but then needed a bottom end gasket set available from Burton Power which also came with crankshaft seals and ‘O’ rings. Also, John advised I got a gearbox front oil seal which I purchased from Bearing Kits UK but ended up getting a gearbox oil seal set just in case.
The Corsair had been a bit tricky to start since it’s last outing to Blandford before Christmas. Unfortunately, it let me down on New Years Day as I had planned to go to a classic meet at Sturminster Newton but it failed to start and I drained the battery in the process. A couple of weeks later, with the battery on trickle charge, I tried it again and after several turn overs I just caught it enough for it to cough in to life on minimal choke and after several pumps of the accelerator (gas) pedal.
Friday evening (10th Aug), I had just eaten my dinner and I get a phone call from John saying he was at the side of the road on the B3081 just before Zig Zag Hill and was I available this evening? The washing up could wait until I got home. And no, he hadn’t broken down – there was plenty of that the day before, but John said the Corsair was running well and he had been out to Six-Penny Handley and back without a hitch or hiccup and could come over to pick me up in it. After collecting me and with John driving it back to his workshop, I could feel the car was running so much smoother, even as the passenger and it seemed responsive on the throttle.
Once back at John’s, the Corsair was switched off with no over run even if the temperature gauge was, probably incorrectly, reading hot. John then went on to explain the shenanigans he had on the Thursday with it breaking down on him most times he took it out. It was as if the fuel system was being starved every so often and he thought it was the fuel tank not having a breather pipe (it does, as I fitted a new pipe with the recent tank re-install). He drilled two tiny vent holes in the filler can to help alleviate this, but still the problem occurred intermittently. He then noticed the over flow return pipe running back to the fuel tank had a leak, so he cut out the bad section and replaced with a section of pipe. From there the Corsair would continue to be starved of fuel but seemed worse on the next test drive, so he disconnected the return pipe from the carburettor running back to the fuel tank, and then the Corsair ran/drove normally.
An overflow pipe had since been connected and re-routed to over flow away from the engine bay, but not to the fuel tank, for now. At least all seemed well with the Corsair. John said he had tuned it with about 10° Advance and with the new carburettor, the mixture screw now allowed for more finer tuning. Test drives over the weekend beckoned but I had to have a quick cruise through the town’s high street before I took it home to put away in it’s garage.
A few little jobs to do over the coming months will be to replace the flexible brake pipes as the bores of them maybe too small and possibly causing a temporary lock up of the brakes, as John experienced when the car was parked up. I’ve also to put the drivers window back in, now that John has also repaired the window glass runner utilising a window runner from a MGB.
Since the tale of two fuel tanks and one breakdown, I did manage to get the Corsair to John’s (AJ Restoration) just and I mean only just. For the last half mile and going up a gentle hill, the car was reduced to chugging along at 5-10 miles an hour in first gear while I was waving on the stream of traffic that built up behind me. It was only so I could have a clear run up to John’s gates for it to stall and then roll the last bit to be left unceremoniously in the middle of his yard. That was early July and the arrangement was as before, to fit it in with his other bigger paid jobs. Around this time I decided to buy an new old stock (NOS) Zenith Carburettor 36 IV (3046) with a 28 choke from the Carburettor Hospital, based in Essex. The photos below don’t do it justice – the camera on my phone was struggling to digitally process the clean flat grey colour.
Since the Corsair spluttered to a halt on the on the driveway back on Christmas Eve, I’ve been tinkering away trying to solve the fault. Testing the fuel pump, checking the points and condenser, rebuilding the carburettor and fiddling with all manner of idle mixture settings, had not made any difference. The Corsair would start, fire on the first turn over then cut out.
Went to see John today as the Corsair is now up and running very nicely, especially now that it can be tuned properly and has many new ignition components. It has been booked for an MOT on Thursday – just to see if anything more needs doing. Fingers crossed, eh?
John and Peter at AJ Restorations had finally got the distributor out. They eventually used an aluminium drift from beneath and persuaded it out, after drilling the alloy body to release it from it’s infernal grip on the cast iron block.
It didn’t look too good but I was assured in a phone call to H&H Ignition in Dudley, Birmingham that they could refurbish anything so long as the internal main shaft was OK along with the cog drive. John also had a contact that may have a couple of spare distributors for future reference, just in case mine was unserviceable.
So that’s it for now. I’ll be taking this little lot up to H&H Ignition on Tuesday (15th Aug) and see what they have to say.
The distributor has been causing all manner of problems for John and Peter at AJ Restorations. It had battery acid soaked into it for a week and it still wouldn’t budge. Heat and brute force with massive grips could not move it, either.
Upon visiting John last Friday (28th July) it has been decided to dismantle the distributor to leave the aluminium shell and then cut the bugger off and then drill out the seized in remains. I have been assured from an ignition specialist that they can rebuild the distributor from the bits I supply.
In all this time, I’ve been trawling Ebay for a replacement but they are all Dizzy’s from V4 Transits or quite pricey only to be rebuilt anyway. The distributor I had (Bosch) is for a Pinto and manufactured in 1976 and will be on Ebay soon.
It will get done, though it’s costing a lot more than first thought.