The Lotus Grand Tourers

Finally on 30th Dec the puddles in the roads disappear and it's time for a test run.
I was all excited, and got my son Nick out to guide me out of the garage. Then found the clutch was seized and I couldn't get it in gear !
Unfortunately Nick then had to go back to Cardiff while I puzzled over my next step ....
After about an hour I had a little brain wave, and tried starting it in reverse with my foot on the clutch - a bit hazardous with the car in the garage, but eventually there was a big clunk after a few attempts - all good - phew !
Double checked the tyre pressures and warmed the engine up while pumping the fronts up to 30psi. Rears were 35psi, which seems a bit high, but I left them alone.

I did 4.5 miles in the end. Brakes were a bit scary at first, but definitely improved through the run.
I eventually got enough confidence to hit 60 a few times, used all the gears, and ran it up to about 5,000rpm.


Nice and hot when I got back - probably the first time the oil has got vaguely warm for a very long time. The pressure was starting to reduce a bit when I stopped at the end.

Temperature seems to be settling at just over 100 according to the gauge, but I suspect it's over-reading. There's certainly no evidence it's running that hot when you open the bonnet to check. And it doesn't appear to have used any water.
I'd be interested to hear thoughts on the temperature ?

Finally I tucked the car away back in the garage.
Next steps - take it off SoRN and get it ready for an MOT.
I'll hopefully be able to register it as a classic car, but I'm thinking the MOT is still a good idea to be on the safe side.

Happy New Year All,

Tyre pressures for the original 215/50/15 Goodyears was 24 psi all round. Pressures for the 205/60/14 Goodyears on the Elite was 22 psi all round. If you want a compliant ride, don't over inflate.

I currently use 26 psi all round for 215/45/15 Toyos for a compliant ride. The Excel has 50:50 weight distribution so pressures are same front and rear. 30 psi is unnecessary and 35 psi potentially will wear the centre of the tread/afford less contact area across the entire tread.

You will know if you have under inflated for the car weight/tyre type if you see a dark band around the centre of the sidewall after a 70 mph run up the motorway. The dark band indicates over heating due to overflexing of the sidewall. Take some air out, it'll feel nicer to drive.

The ride felt pretty compliant, but almost anything does compared to a Focus RS tbf.
My Excel has Nangkang 205/50 x 15 tyres - they look like a Goodyear NCT copy in terms of tread pattern. Not sure why a previous owner went for these, but they've still got the stickers on, so won't be getting changed any time soon.
I'll take your advice before I take it out again thanks Pete.

Time for an update ....
Not masses of progress since last time, but here goes.

1. Brakes :
Another run and some checks showed that the drivers side brakes were both sticking.
Rear proved straightforward to solve by pumping the piston in and out a few times.
Inspection of the front showed a damaged main dust seal which was hiding lots of debris inside. Thorough clean and new seal kit fitted - this is all now moving freely as it should.
Passenger side handbrake not working, but fortunately only needed adjusting.
All brakes now seem to work consistently and ready for MOT to confirm.

Wipers and washers :
Wiper parts all present in the boot and it seems to work well now they're fitted - a rare easy one
Washer non return valve blocked and leaking. In my efforts to get the hose off the pump I managed to snap the outlet pipe off the pump . After much searching I managed to find a straight swap for the pump, so no major issue in the end.

New hose and jets adjusted - all now working as it should.
I've put a post in the parts alternatives section in case someone else has the same issue.

Exhaust :
Repaired minor leak at rear of centre box with a bit of innovative fabrication using the cover from a central heating diverter valve, an exhaust clamp, and gungum paste.


All now sealed and sounding nice - should last a good while I reckon.


Also, 3 of the 4 rear exhaust hangers were missing, so replaced those. Exhaust exit pipes now fit a bit more snugly in the recesses under the rear bumper, and less stress on the hangers at the front of the rear boxes that were previously taking all the load.

Diff :
Minor oil leak - I was worried that this was from the main gasket, but it appears to be from the filler plug, which was a bit of a relief.
Oil topped up and new sealing washer fitted. Luckily the filler plug is accessible by socket and it came straight out without even the need for an extension bar !
I may change gearbox and diff oil later when I've got the car properly on the road, but for now at least I know all is well protected.

Rear Window :
Significant leak along top edge - now resealed and tested, so ready for fitment of new headlining and interior trim pieces.

Engine Temperature Issue :
First I realised that the fan relay was sticking, so the fan being on was misleading me in terms of the engine being up to temperature - new relay fitted.
I managed to find some temperature recording stickers and ran a test to see what the temperature really is.

This proved that the fans come on at 90degC as they should and hold the temperature there, but the gauge in the car reads about 117degC when the engine is really at 90. Understandably, this test required a bit of courage as I watched the temperature gauge continue to climb past 110degC ! Not sure whether this is a gauge or sender issue, but at least I now know what's really happening and the temperatures are all good. Also, the oil cooler appears to be switching in as it should, so overall temperature management is all working properly.

Lights work intermittently :
Centre dash removed to enable the top row of switches to be inspected and cleaned - all now working reliably.

Road Test :
Just a road test to check all is now ready to book an MOT, and then get on with enjoying the car while I chip away at the remaining jobs - or so I thought .....

Car now insured so I dropped the tyre pressures and took my daughter out for a bit of a longer road test.
It ran really well for about 10miles, then started getting very lumpy at idle .
I started messing with the mixture, trying both leaner and richer, but the rough running just started getting worse and worse with each run up and down the road.
I did a bit of head scratching and finally thought this might be down to putting a couple of gallons of normal unleaded in, so I duly went out and bought 21litres of Tesco Momentum.
Further adjustments and more short road tests revealed no improvement - in fact it carried on getting worse, to the extent that it would barely get up to 20mph after a mile or so ... This led to me nearly getting rear-ended so more serious intervention is obviously needed before going back on the main road.
Plugs checked and and one found to be 0.45mm gap, but otherwise all ok.

I re-gapped No2, and re-fitted them, but perhaps unsurprisingly there was no improvement.
It's difficult to describe the symptoms effectively, but as best I can :
"lumpy thudding with no power - ticks over, but will not pull at all" (although it's always made it up to a mile home when running like this, albeit very slow and lumpy).

Fortunately I had planned to go to the Classic Car Show on 23rd March, so took the opportunity to seek some advice from the team on the Grand Tourers Stand. Thanks to Tony, Alan and Richard for your advice. It was good to see you again Tony, and I also enjoyed our long discussion Alan - quite a few things for me to try - some especially simple ones from Alan that I had not thought of before. It's great to put faces to names, and I hope to see you again soon, preferrably with me in a Lotus !

We are now in the last week of March, and the car should have been MOT'd by now, or at least have a to-do list from the test.

Time to get on with some more testing, starting with the simple stuff suggested by Alan :
First I checked the timing. It was around 13 at idle going up to about 29deg BTDC above 3,000rpm. This is now adjusted to 9deg and 25deg respectively, as per spec. Doing this also enabled me to check whether the ignition advances as it should, which was one of the simple tests Alan suggested. All seems good in terms of the mechanical advance, unless it is potentially sticking on a proper run, however I'm thinking this is unlikely as I've tested it with the engine fully hot. No perceptible change in running following the timing adjustment, but I didn't really expect that to change much based on the symptoms.

Disconnecting the rev limiter didn't seem to make any difference, although I will confirm this on a longer run if I don't manage to solve things elsewhere.

Back to suspected fuel issues - I checked the carb inlet fittings, expecting the little filters to possibly be blocked - this was my most promising option so far based on the symptoms. There are no filters in these fittings, so that's another thing ruled out. Also, I tried to order new ones from SJ, but it seems they are no longer available from anywhere ?

Time to start stripping the carbs, and soon started to find some issues - I think the pictures tell most of the story :
Check the idle jet o-ring


Not sure what's going on with these jets, but more importantly, check the old fuel varnish in the bottom of the float chamber


Time to bite the bullet and take the carbs off for a proper inspection and service.
Then saw the condition of the spacer o-rings - definitely not helping, but probably not the only problem.


I know the pump chamber non return valve is critical on these carbs and can be prone to sticking, especially with old fuel, so stripped off the bottom end and found lots of debris in the pump cover assemblies. One carb was much worse than the other for some reason, which is maybe why I don't get a total failure with the rough running ?
Also, I'm thinking the detergents in the new fuels have gradually started to break up the old varnish and that might be why it's getting worse ?
Internals now all cleaned out and waiting for o-rings from SJ (idle jets, pump jets, and spacers). Interestingly, Eurocarb say the normal 45DHLA spacer o-rings won't fit a Lotus due to the spacer grooves being too deep - they recommended going to SJ or Lotusbits for this part. Having taken some measurements I'm not entirely convinced, but I ordered from SJ in any case to be on the safe side. They also sell the internal carb parts I needed, so that saved a bit of postage.
Carbs now awaiting o-rings before re-assembly and test.


While the carbs are off I also took the opportunity of looking in the distributor for any evidence of loose/damaged wires :

All looks ok I think, but I'm not sure I can see the bit that other people have reported problems with ?
I was half tempted to take the distributor off and strip it down while the carbs are out of the way, but I'm not so keen despite Tony's re-assurance on the simplicity. Hopefully I've found enough other contributing factors to fix the issue.

With a bit of luck I will have the car re-assembled next week - I'll report progress (or lack of) after taking it out.
In the meantime, if anyone has any other thoughts, advice or suggestions based on the pictures and description of symptoms then they would be gratefully received.

Cheers all and thanks again to Tony, Alan, and Richard for the advice

Try these for parts

https://www.dellorto.co.uk/

An easy check for the distributor pick up is to check the resistance at the AB14. It should be around 2.5K ohm.
when I checked mine on the car, I got anything between an open circuit and a reasonable resistance. The reading is VERY sensitive to the quality of the contact you make to the red and Blue wire.

After removing, I set it up in a vice, which enabled me to "wiggle" all areas to see where I had a bad contact


Despite having a new magnetic pick, so I knew the cable was good to the plug, I eventually found that the 2 Pin Bullet connector wasn't reliable. You can see in the above picture that it now has a Splint taped along side the plug to maintain good contact ( hangs down bottom left along side the larger vice). Things finally settled down at a consistent 3.138K ohm

If you don't want to remove the dizzy, you could try just removing the pick up.

Have you access to the full Lucas test sheet - You can find it in the attached link towards the foot of Page 3.
viewtopic.php?t=12374&start=30

Thanks Tony - I will try that before I put the carbs back on

Hawaiis0 wrote: Thu Apr 03, 2025 19:06 Try these for parts

https://www.dellorto.co.uk/

They would normally be my first stop for carb parts Stu, but it was these guys who pointed me to SJ or Lotusbits. They also don't list the carb inlet filter unless you have a banjo fitting.
I'm thiinking I will have to break into the fuel line somewhere and fit a filter sooner rather than later in case the debris has come from the tank.

Just checked the resistance of the magnetic pick-up "at the AB14".
I'm getting a consistent 3.5k ohms with the wire routed and pulled a few different ways, so all good there I think ?

malrig wrote: Sat Apr 05, 2025 14:29 Just checked the resistance of the magnetic pick-up "at the AB14".
I'm getting a consistent 3.5k ohms with the wire routed and pulled a few different ways, so all good there I think ?

I have a Lucas AB14 tester if you are ever over west oxford way. Happy to loan it

I have a Lucas AB14 tester if you are ever over west oxford way.

Are you going to Castle Combe and it portable we enough to bring with you? I have spare which I'm sure is good, but like to test.

I'm getting a consistent 3.5k ohms with the wire routed and pulled a few different ways, so all good there

That's a good test to have confidence dizzy pick up is good. Allows you yo focus on the carbs.

Tony

MetBlue wrote: Sun Apr 06, 2025 11:35

I have a Lucas AB14 tester if you are ever over west oxford way.

Are you going to Castle Combe and it portable we enough to bring with you? I have spare which I'm sure is good, but like to test.


Tony

Snap - would be good to test my spare.

Yep think that might be doable

Yep think that might be doable