The Lotus Grand Tourers

Hi all,
Once mine (1985 Excel non-SE) is warmed up, other than a slight stumble at 2300/2800 depending on the mood my car runs pretty well. Starts instantly cold or hot.
Normal warm up for me is Choke on, start with no throttle (or the merest whiff) then about 20 seconds with the choke on, take choke off, and a couple of minutes waiting until I can confidently blip the throttle without a massive stumble or killing the engine. Then drive off.
If I set off straight away I have to be very careful on the throttle, seems like at tickover or 50% plus it's OK, but if I'm accelerating away from a junction or similar at about 20%, I can barely keep it running, in fact I'm sure I could stall it if I wanted to.
Carbs were rebuilt about 3000 miles ago.
Coil and leads are original as far as I know, but I'll be putting some new ones on soon.

It's not a problem if the answer is "they all do that sir" but if it's not behaving as it should I want to rectify it.

Cheers, Dan

Based on my S1 Elite, which behaves perfectly acceptably well in such conditions, I'd say something is wrong. I'd expect the later cars to be better not worse than mine.

Andy

Not sure that I’ve mastered the cold start, but I was told that you don’t need to use the “choke” and it certainly doesn’t seem to make the process any easier on my non-SE.
Once I have got it started and idling (lumpily), I find that I need to coax it gently until it revs to about 2000 without stumbling, at which point I can pull away without any further trouble.
I thought it was just one of the quirks of a “performance“ engine with carburettors and a manual choke.

My Excel is an 84 LC model, 43k miles on the clock and had a full professional rebuild of the carbs in the last 1000 miles. It's a bit pampered, so doesn't get used a lot in the winter. However, general cold starting procedure is:
- Ignition on and wait until fuel pump stops ticking (ie float chambers are full)
- Two pumps on the throttle
- If it's cold weather, pull the choke out. The colder the weather, the more choke to use
- Turn engine over with throttle closed, then push down throttle a bit when it fires up. If it's cold weather and a bit reticent to start, give it another pump or two on the throttle.
- Generally it's a little lumpy initially, so use a gentle throttle to keep it running (first minute or so)
- Cold weather - choke can ususally be dispensed with after a minute or two.
At this stage the engine is not up to full running temperature and maybe running a little lumpy with a lowish tickover speed but still pulls pretty cleanly. Within a couple of mins the temp gauge will be moving up the temp gauge, the idle speed comes up and it's running smooth with no probs. I never drive it hard until the water temp is up (ie about half way on the gauge).

Warm starting is easy - don't touch the throttle, just turn it over and then ease open the throttle when once it fires up.

Have you still got the original airbox on, I only ask cos some remove them so don't get a warm air feed. The reason I ask that is, depending how cold it was when you tried it, you can get carb icing in the intake. I used to live at the bottom of a small valley that held cold air on a still day and it could be a pain, to the extent that it would cut out but restart after the ice had melted.

Bash

Your car's not set up right Dan.
I never use the choke.
Wait til pump stops ticking. Two pumps on accelerator in summer, 4 or 5 in winter, turn key and were running. If I wanted, I could drive off pretty much immediately with minimal hesitation.
Sounds like it's running a bit lean. What's plug colour, both after tick over and cutting off mid run?
Have you cross checked jets against the correct spec for your model? There's quite some differences between early and late calls - 10 different specs IIRC. My car had the wrong jets (fitted by a known Lotus specialist with the older cars - not Lotusbits- an attempt to compensate for another fault). Once I'd changed the dizzy pick up and put the jets back to std it transformed the car.

Starts okay even freezing but have to wait 2/3 minutes for it to warm up...

Excel lc 1984 switch on wait for fuel pump tap throttle once full choke start tick over 3,to 400 revs low wait for oil pressure choke off warms up to approx 40 before i drive normally ticks over at 1000 rpm. Dave