Cold start stalling

[Sentinel]

This issue is battery voltage related. If the battery voltage drops below about 12.5V, it will start happening. Put your car on a trickle charger and you’ll see the issue goes away.

I think the ECM that controls the fuel pump is sensitive to voltage and is not priming when the battery voltage is low.

 

[danmessy]

While ECU / software is the underlying problem I am now pretty sure that the type of fuel used does make a difference. I have generally used Good quality E5 Fuel (Shell / similar) and had cold starting issues but having switched to lower octane E10 is has started fine every time (once the higher octane stuff was fully cleared through).

Wait, if someone could chime in and confirm as our fuel ratings read different in Australia to UK:

E5 = 98?

E10 = 95 ?

And if so, you are stating that the lower octane E10 (i.e. 95) has reduced your cold start issue? I thought 98 was recommended minimum?

This issue is battery voltage related. If the battery voltage drops below about 12.5V, it will start happening. Put your car on a trickle charger and you’ll see the issue goes away.

I think the ECM that controls the fuel pump is sensitive to voltage and is not priming when the battery voltage is low.

What are you using to check battery voltage? I let my Scorpion Tracker subscription lapse after the free period, that was the only way I was reading my battery really.

For visibility, as I have previously posted, my cold start issue entirely resolved several months ago (i think post-summer for my location), and I attributed it to changing to CALTEX/AMPOL 98 only. The issue has now came back and is 100% cold start on first attempt every new day at the moment, which is really frustrating. Second start is perfect.

Recently I emailed the dealer to when for a fix and the dealer stated in an email (quote): "the issue appears to be related to atmospheric conditions. As the warmer weather has started the issues seems to get worse. I am being told lotus is still working on the issue". I'll follow up in the new year.

Cheers all, stay safe over the Christmas / New years!

 

[Andrew P]

And yet the one of the 1st questions asked was 'you are using premium fuel'. The Ecu, engine wiring loom, various sensors, solenoids and coil packs have been replaced in the quest for a solution. Hopefully, I can pick the car up on Friday as it is being tested tomorrow after all work was finished today.

Premium means branded non supermarket fuel so it has better additives whether 95 or 97-99 octane rating. I have been told by someone with good knowledge of the facts on this at Hethel that the lower octane rating actually helps this issue.

 

[danmessy]

Premium means branded non supermarket fuel so it has better additives whether 95 or 97-99 octane rating. I have been told by someone with good knowledge of the facts on this at Hethel that the lower octane rating actually helps this issue.

I will give 95 a tank or two, will report back if positive results or in 4-8 weeks

 

[Man.v.Cars]

Premium means branded non supermarket fuel so it has better additives whether 95 or 97-99 octane rating. I have been told by someone with good knowledge of the facts on this at Hethel that the lower octane rating actually helps this issue.

Yet my car will have been at the dealers for 9 weeks on Friday, they had no idea and so contacted Lorus to have them walk through what they wanted doing. Data collection from everywhere possible led Lotus to approve a new ECU and wiring harness.

The problem started when we got the first cold snap in October, 1st start the rpm were all over the place, turn off and restart was fine.

Lotus state you can use a lower octane but performance will be affected and over time seals may corrode quicker.

 

[Andrew P]

Yet my car will have been at the dealers for 9 weeks on Friday, they had no idea and so contacted Lorus to have them walk through what they wanted doing. Data collection from everywhere possible led Lotus to approve a new ECU and wiring harness.

The problem started when we got the first cold snap in October, 1st start the rpm were all over the place, turn off and restart was fine.

Your issue sounds different to the one that a lot of us have been experiencing. There will be multiple different issues across thousands of cars I am sure. The fuel change is worth a try for many people - judge it after 2nd fill. Mine went from bad start every time to absolutely perfect every time. It is not related to battery health or anything else. I don’t use a trickle charger & it starts fine after a week unused

 

[Man.v.Cars]

Your issue sounds different to the one that a lot of us have been experiencing. There will be multiple different issues across thousands of cars I am sure. The fuel change is worth a try for many people - judge it after 2nd fill. Mine went from bad start every time to absolutely perfect every time. It is not related to battery health or anything else. I don’t use a trickle charger & it starts fine after a week unused

If the problem is still there oll give it a go, fingers crossed my problem has been solved.

As a slight aside the service manager told me the wiring harness is booked in by Lotus to be a 5 hour job, it took them 15 hours. Every repair has been way over Lotus booked time for a job.

 

[Sentinel]

Wait, if someone could chime in and confirm as our fuel ratings read different in Australia to UK:

E5 = 98?

E10 = 95 ?

And if so, you are stating that the lower octane E10 (i.e. 95) has reduced your cold start issue? I thought 98 was recommended minimum?


What are you using to check battery voltage? I let my Scorpion Tracker subscription lapse after the free period, that was the only way I was reading my battery really.

For visibility, as I have previously posted, my cold start issue entirely resolved several months ago (i think post-summer for my location), and I attributed it to changing to CALTEX/AMPOL 98 only. The issue has now came back and is 100% cold start on first attempt every new day at the moment, which is really frustrating. Second start is perfect.

Recently I emailed the dealer to when for a fix and the dealer stated in an email (quote): "the issue appears to be related to atmospheric conditions. As the warmer weather has started the issues seems to get worse. I am being told lotus is still working on the issue". I'll follow up in the new year.

Cheers all, stay safe over the Christmas / New years!

Testing voltage using a multimeter across the battery terminals.

When it drops below 12.5V, cold start issues start. Above that it’s fine. Same with Ampol/BP/Shell 98 here in Aus.