free hit
counters
Hesitation under load.... - Engine & Ancilliaries/Gearbox - The Lotus Forums #ForTheOwners Jump to content


Hesitation under load....


Recommended Posts

Right.

I suspect this may be a long one so I apologise in advance.

My car is being rather strange.

Half the time it drives beautifully with no issues. The other half of the time, she's a nightmare.

The main symptoms are.....

Uneven idle and cutting out.

Lack of power. Especially evident at motorway speeds when the accelerator pedal almost stops working. Just loads of hesitation and power loss.

She becomes just jerky and unwilling to rev.

But.......as with yesterday.....after doing that for 10 mins. A 5 min rest and then start again, she's back to normal!

No codes or warning lights present.

I've chased the usual suspects and replaced.....

MAF sensor.

Brake pedal sensor.

Clutch pedal sensor.

Full ECU reset.

Upstream o2 sensors.

Throttle body clean.

Spark plugs.

We do have a spanner on but that is for the electric heat pump that would usually operate after shut off.

Has anyone please got any other ideas?

I want to love her but at the minute can't trust her for any journeys at all really. 

Thanks all in advance.

Link to comment
Share on other sites


Upgrade today to remove Google ads and support TLF.

Its odd that it's not throwing a spanner or code? Coil pack is the only other thing I could think of. I'm not sure if you can read the afr from the ECU, that might show something. The O2 sensor caused some issues on mine and if you can get obd software that graphs the output then its sometimes easier to see and interpret rather than just a fluctuating reading.

What about fuel pressure?

Link to comment
Share on other sites

Throttle actuator / throttle body?

I know it is different because yours does not throw a code, but mine threw a CEL light and traction control failure light recently after a very wet short drive. It drove well on the road but threw the light when I restarted it to put it in the garage. Idle would go crazy (up to 3000 rpms then down) with very limited throttle response (ie. It would not follow my input). I let it dry, restarted a few times a week later but the CEL continued (traction control light disappeared). Connected the OBD reader: it had two stored codes that read throttle actuator performance/range / forced Idle. Cleaned the codes and now works fine.

Link to comment
Share on other sites

22 hours ago, 21gg said:

Its odd that it's not throwing a spanner or code? Coil pack is the only other thing I could think of. I'm not sure if you can read the afr from the ECU, that might show something. The O2 sensor caused some issues on mine and if you can get obd software that graphs the output then its sometimes easier to see and interpret rather than just a fluctuating reading.

What about fuel pressure?

Fuel pressure is one that interests me......fuel pump is reasonably loud when you press the immobiliser button...not sure if they all slightly loud?

Not found anyone else who has changed a fuel pump......

7 hours ago, EGTE said:

air filter?

Changed that as well!

17 hours ago, Arregueti said:

Throttle actuator / throttle body?

I know it is different because yours does not throw a code, but mine threw a CEL light and traction control failure light recently after a very wet short drive. It drove well on the road but threw the light when I restarted it to put it in the garage. Idle would go crazy (up to 3000 rpms then down) with very limited throttle response (ie. It would not follow my input). I let it dry, restarted a few times a week later but the CEL continued (traction control light disappeared). Connected the OBD reader: it had two stored codes that read throttle actuator performance/range / forced Idle. Cleaned the codes and now works fine.

I also keep thinking throttle body......but its a serious expense......so want to be more sure before buying one.

What I don't understand is how it's so sporadic.....surely if a part had failed, then really it shouldn't work anymore, but there's times when the car is absolutely perfect!

Thanks all so far. Its genuinely appreciated!

Link to comment
Share on other sites

What I don't understand is how it's so sporadic.....surely if a part had failed, then really it shouldn't work anymore, but there's times when the car is absolutely perfect!

Thanks all so far. Its genuinely appreciated!

 

It is why I suspect a sensor somewhere, or its connections.

 

 

 

 

Link to comment
Share on other sites

Funnily enough, before the codes popped up, mine was sometimes struggling a bit to get pushing from low speed or out of a crossroad in second gear with some coughing, etc.. After the codes were cleared, it pulls much better now. They seem to have a character of their own, these things.

I have had the brake pedal sensor greased, the MAF sensor cleaned and now this to fix similar issues, so they all seem to be "characterful" parts of the car and a likely source of annoyances.

I am sorry I cannot be of more help.

Link to comment
Share on other sites

🤣 I replaced the fuel pump on mine as the car stopped a couple of times before eventually refusing to start. It didn't throw any codes though. I would expect a knackered fuel pump to play up a bit but yours does sound if it's something else. You can pull the fuel pipe of the rail and put it into a container so see if it's pumping but if yours is running then I would say it is. Mine had corroded, presumably from when the GTEs were left to sat for a few years and it must have got condensation in the tank. Not sure how you can monitor fuel pressure though. If you do go down the fuel pump route drop me a DM before you spend £1200 or what ever it is on one from lotus. 😁

Just another thought, the fuel filter, it's on the pump in the tank, not external so could be this?

 

Link to comment
Share on other sites

Fuel pump and filter sound like the next logical steps!

I think mine sat for a period of time at some point in its life so could have had some in tank corrosion as well......

Will PM you.....

Link to comment
Share on other sites

  • 2 weeks later...

Yeah blimey! The fumes are intense!!!!

There was some swarf at the bottom of the tank (not sure where that's come from) so had my head in it for a little while sucking bits out.

I feel strange.

Thanks for your help mate 

Link to comment
Share on other sites

  • 2 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...