Tuesday 22 March 2022

Lambda Sensor (Again)


During the GBS trip I decided to do an instrumented run to check the lambda sensor.   I noticed straight away she didn't go into closed loop so after a few miles, while at some traffic lights, I stopped the engine, counted to 10 and restarted her (good thing we don't suffer from the hot starts any more).   She quickly went into closed loop and stayed there for the rest of the trip there.  

Here's the trace. 
As we can see she was scruffy as old boots until the restart and then absolutely fine.  

On the way back the same thing happened, except this time the first attempt at restarting didn't help.  It was a second, later, attempt, again at some traffic lights, that made the difference.,

So what can we deduce from that ?   Although the sensor could be going soft, my first thought is that the heater is not working properly.  As we know my wiring is not the best in the world 😁 I guess while I have the soldering iron out I can redo all the lambda heater joints.   I'll see how that goes.    But there's no mad rush as I don't need it working till the emissions test in August.

Monday 21 March 2022

Cooling OK ?


During the trip to GBS I had a chance to check the cooling


And there was good news.    Here we have her on the way there.  She sat at 85C for the first 2/3rds of the trip.  The blip was when I hit a traffic hold up at the junction of the A17 and A1.  It wasn't enough to trigger the fan and as you can see it rapidly came back to normal when I hit the open road.

And here she is on the way back.  Again a solid 85C.   Although this is a bit deceptive.   At the point where the intake temperature blips I had pulled into Grantham to get some fuel.  As an experiment I switched on the fan as I was in the 30mph zone and that was the result.  

When I got back there was no water in the overflow bottle and the water level was unchanged (and I was bit concerned to find I had forgotten to bolt the nosecone in, it was simply held in position by the bonnet resting on it).  So that is a relief, it means I don't have a leak or a blown head gasket (doesn't mean I shouldn't check it before every trip though😁).   I'm still not convinced that the seal between the pressure cap and the expansion bottle isn't a bit dodgy.  I added an extra rubber seal yesterday to see if that helped.  It may have done.   I also might start getting into the habit of switching the fan on if I can see an obvious trouble spot coming up, or traffic lights or a 30mph speed limit.   It is obvious now that once she gets too hot she starts dumping water and that makes her get even hotter.   Better to prevent her getting hot in the first place.    Or maybe revert back to a 92C fan thermostatic switch from the present 95C one ?

A couple of minor glitches, the carpet on the passenger side won't stay up any more, needs redesigning (not what you would call critical 😁), I think the clutch cable needs adjusting a bit, had a couple of occasions when I couldn't get into second, and someone pointed out that my offside DRLs weren't lighting up.   I have been thinking I would rewire them properly anyway so the soldering iron comes out tomorrow.

Saturday 19 March 2022

GBS Coffee & Cake

 Every few months Great British Sports Cars (GBS)  host a kit car meet at their factory.  GBS took over the Robin Hood fircoolm when it folded and still support the cars so I often attend the meets.   The weather today was fantastic, and I needed to check the cooling system so I decided to go. 

What a cracking drive, 75 miles in total.  Weather fantastic although cross wind on the A1 a bit rough (Only did 7 miles on the A1 though).   Also the sun is now high enough so I don't get blinded on the way back South (which is a good thing as my sunscreen blew off yesterday and was destroyed by the car behind 😁).

Never seen it so busy, there were a huge number of cars, the forecourt was full and cars were parked both sides of the approach roads for 100 yards.    Predominately Zeros, but lots of other kit cars of all shapes and sizes.  Free coffee and the best selection of cakes and biscuits I have seen for some time. 

I must admit that much as I love the Superspec I have a sneaking regard for the Ariel Atom:

Perhaps I could imitate it by taking all the side panels off 😁




I had to park on the road.   Turned out to be a good thing as I could leave when I wanted as most people on the forecourt where stuck there for the duration.   She was probably the oldest car there, all the others looked brand new in showroom condition, she still attracted a few people though so I was kept busy 

Friday 18 March 2022


After the MOT failed with 2 of the front suspension bushes we decided to replace all the rest.   While she was in I asked the mechanic to fit some new shock absorbers I had been given, fit a new speedo cable I had found on EBay, and fit a new rear exhaust mounting that had sheared on the way to deliver the car.

 So picked her up today and we had about a 60% success rate 😁 Front end now completely re-bushed but he said there was no point in doing the tracking until I had driven a few miles to let the suspension settle.   But he did say that one of the wishbones was a bit loose with the old bushes so that may have contributed.   On the drive back she still pulls to the left a bit but nowhere near as bad as before.   He recommended a garage he uses to get all his car tracking checked, so I might do that in a few weeks.   He hadn't fitted the shock absorbers, initially he was worried that springs were a different colour (green rather than blue) which means the strength was different but then on close examination the bottom mounting was slightly wider than the existing ones so wouldn't fit.  

He also hadn't managed to fit the new speedo cable.   Again, at first it looked identical and I had checked that the instrument end as that looked different.  Turned out it was the correct version and fitted perfectly and the original one was the wrong fitting so it could only be pushed in half way.    That explained why it kept coming out.  What we didn't realise was the gearbox end, while looking identical and supposedly for an MT75, was very slightly thicker so when It was pushed in there wasn't enough clearance to fit the circlip.   So he just fitted a blanking plate to the hole, something I have been thinking of doing.   I'm in 2 minds now, I have lived without the speedo for almost 3 years now without any problem.   Or I could go to a firm that build cables and get a bespoke one made up with the gearbox end of the old one and the instrument end of the new one.    But that would be quite expensive.    We'll see.

Finally he had put a temporary solution on the exhaust mount. Unfortunately he has done such a good job I think it might be another case of a short-term fix becoming a long-term solution 😁

Wednesday 16 March 2022

Coolant Problems (again)

Weather was good so it was a good time to have a picnic, so we went to Burghley House on Tuesday.   

Nice day but on the way back I happened to notice the temperature gauge firmly in the red.    Pulled of the road and shut her down.   It sounded like a kettle boiling in the engine.  Sure enough, when I took the bonnet off the system was boiling like mad and coolant was pouring out of the overflow.   After the original problems I have always carried a 2 ltr bottle of water in the passenger footwell.   My only concern was how long I had to wait before I could take off the pressure cap.   I was a bit surprised when I felt the cap and it wasn't hot.   So I risked taking it off, and after a few seconds of releasing the pressure it came off.    So put the 2 ltrs in and started again.   It seemed to be OK but 6 miles from home it shot up into the red again.   Luckily I had stopped in a small village and a friendly house owner filled my bottle up for me and that was enough to get me home.   So I have kept up my record of never arriving home on the back of a rescue truck 😁

So filled her up, using the top of the radiator outlet to make sure I got rid of all the air.   Drove her today, 11 miles each way and the needle didn't even get to the 'N'.    Once she has cooled off I will check the water level and make sure I don't have a new leak.   I hadn't checked the water level for months, so I think it just gradually gone down until it was suddenly below the water pump and the sensor and then it just shot up to the red as the circulation stopped.   That would explain why the pressure cap was cold and also the engine definitely did not feel it was excessively hot.