2020 310R 1.6 Sigma --- Fluttering/power loss at full throttle in any gear

[Deman USA]

Good day fellow members and hope all is well. 

I recently purchased a 2020 310R with 1300 miles and in very good condition from Rick & Greg at Time Machine Motorsports, very polite, professional &  awesome guys to deal with. 

 

Everything looked/looks great on it but I haven't been able to drive it since it was delivered and finally got a chance to last night,,,,,but returned it back to the garage 2 miles later.  

 

At full throttle (does not matter which gear) it starts cutting off power as if your hitting the rev limiter and sputters/flutters like a turbo setup when an intercooler pipe comes loose.

 

Being this is my actual first Caterham I wanted to see if any of you have had or heard of this issue.

 

I was searching in the middle of the night last night and came across that an immobilizer or TPS can be the issue here.

 

Was told to disconnect the battery and touch the leads together to clear any faults.

 

We only have 91 octane here in Arizona so was thinking of adding 100 octane to it to clean it possibly

 

Any info would be appreciated so I can experience the joy in this beauty

 

Any local Phoenix area members feel free to chime in with a good service center in the area

 

Cheers,

Dino 

Edited May 9, 2023 by Deman USA

[Croc]

To help think through the problem, some questions to better understand:

 

1) Where in the rev range are you when you experience the "fluttering"?  Low down, mid way, or upper end closing red line?  Or maybe its across the full range?

 

2) Does it only happen at full throttle when foot is on the floor?  Does it happen mildly at say 75% throttle and get worse as you push closer to 100% full throttle?

 

3) Is it a flutter or some form of stutter as if fueling is being cut or ignition is being cut?

 

I am trying to discern whether it is TPS or ECU or some other fueling issue.  

 

Not convinced on immobilizer as that is normally a hard cut when it kicks in by accident.  Never heard of soft cutting engine from one of those.  

 

What does the Caterham dealer say?

[11Budlite]

Good info from Croc, and I would pursue his suggestions further. I would also check to see if you have a MAP sensor as documented in your other thread on the unused connectors.

 

I'll add my experience with my 2019 310S. The only running issue I've had was a stalling problem when letting off the gas and coming to a stop. Once driving and accelerating there were no issues. I ended up getting the MBE cable/interface from SBD so I could monitor the ECU and adjust the TPS. Once the TPS sensor was adjusted to the proper voltage, the stalling issue has improved. I think this is the one here: https://sbdmotorsport.co.uk/product/mbe-map-kit-3-can-basic-can-mapping-kit-for-mbe-can-based-ecus/

 

You can also download the software for free from the same site: https://sbdmotorsport.co.uk/product/easimap-6-pc-software-easimap-6-pc-software-download-for-free/

 

I removed my immobilizer because I didn't need it and wanted to remove all that extra wiring and hardware. It wasn't causing any running issues on my car. If you want to remove yours, here's a thread on the removal on my car: 

I can send you more info on how to do it if you're interested. 

[JohnCh]

21 hours ago, Deman USA said:

but returned it back to the garage 2 miles later. 

 

Is the above accurate or was the car already at operating temperature when you tried full throttle?  If you had only driven it 2 miles at night, it's unlikely the engine was up to temperature.  It could be that at full throttle, the coolant enrichment map was making a big fueling correction contributing to or causing the issue.  Have you tried full throttle when the car is up to temperature?  

 

-John

[Deman USA]

6 hours ago, Croc said:

To help think through the problem, some questions to better understand:

 

1) Where in the rev range are you when you experience the "fluttering"?  Low down, mid way, or upper end closing red line?  Or maybe its across the full range?

 

2) Does it only happen at full throttle when foot is on the floor?  Does it happen mildly at say 75% throttle and get worse as you push closer to 100% full throttle?

 

3) Is it a flutter or some form of stutter as if fueling is being cut or ignition is being cut?

 

I am trying to discern whether it is TPS or ECU or some other fueling issue.  

 

Not convinced on immobilizer as that is normally a hard cut when it kicks in by accident.  Never heard of soft cutting engine from one of those.  

 

What does the Caterham dealer say?

Hi Croc,

1---looks like anything above 3k rpms

 

2---75-100% throttle

 

3---stutter is more accurate and thinking more of a fuel issue

 

I did fill it with 100 octane last night so will take it out later today if weather permits to see if it makes a difference 

[Deman USA]

6 hours ago, 11Budlite said:

Good info from Croc, and I would pursue his suggestions further. I would also check to see if you have a MAP sensor as documented in your other thread on the unused connectors.

 

I'll add my experience with my 2019 310S. The only running issue I've had was a stalling problem when letting off the gas and coming to a stop. Once driving and accelerating there were no issues. I ended up getting the MBE cable/interface from SBD so I could monitor the ECU and adjust the TPS. Once the TPS sensor was adjusted to the proper voltage, the stalling issue has improved. I think this is the one here: https://sbdmotorsport.co.uk/product/mbe-map-kit-3-can-basic-can-mapping-kit-for-mbe-can-based-ecus/

 

You can also download the software for free from the same site: https://sbdmotorsport.co.uk/product/easimap-6-pc-software-easimap-6-pc-software-download-for-free/

 

I removed my immobilizer because I didn't need it and wanted to remove all that extra wiring and hardware. It wasn't causing any running issues on my car. If you want to remove yours, here's a thread on the removal on my car: 

I can send you more info on how to do it if you're interested. 

Hi  11Biudlite,

 

much appreciated on these links.  I will definitely

pick it up to have

[Deman USA]

2 hours ago, JohnCh said:

 

Is the above accurate or was the car already at operating temperature when you tried full throttle?  If you had only driven it 2 miles at night, it's unlikely the engine was up to temperature.  It could be that at full throttle, the coolant enrichment map was making a big fueling correction contributing to or causing the issue.  Have you tried full throttle when the car is up to temperature?  

 

-John

Hi John,

I let the car sit for at least 10 mins that night

It was also around 92* outside that night.  

I will be taking out tonight to drive at low speeds for a while before giving it full throttle to see if that helps.

 

[JohnCh]

Thanks for clarifying.  I cringed when I read that as full throttle and high revs with the engine still cold  

 

I just took a look at the factory map for the Duratec and there is very little coolant temp correction, but there is fairly significant air temp fueling correction.  Based on your other thread, and assuming the Sigma map is similar, and like the Duratec, the Sigma also uses the MAP sensor as an air temperature sensor, I wonder if that is the issue?  Check to see if the MAP sensor (should be in the back of the intake?) is plugged in.  If it is, unplug it and make sure all the pins on the connector are fully seated.  I've seen a bad connection on a new Caterham before caused by a poorly installed pin at the factory.

 

-John

[Deman USA]

1 hour ago, JohnCh said:

Thanks for clarifying.  I cringed when I read that as full throttle and high revs with the engine still cold  

 

I just took a look at the factory map for the Duratec and there is very little coolant temp correction, but there is fairly significant air temp fueling correction.  Based on your other thread, and assuming the Sigma map is similar, and like the Duratec, the Sigma also uses the MAP sensor as an air temperature sensor, I wonder if that is the issue?  Check to see if the MAP sensor (should be in the back of the intake?) is plugged in.  If it is, unplug it and make sure all the pins on the connector are fully seated.  I've seen a bad connection on a new Caterham before caused by a poorly installed pin at the factory.

 

-John

I don't see any MAP sensor anywhere so I don't think there is a MAP sensor on this sigma and its a dead plug they leave on the harness.

found this info on another forum 

 

"The Focus MK2/MK2.5 with 1.4 and 1.6 Duratec (Sigma) engine do not have an Idle Air Control (IAC) valve or Mass Air Flow (MAF) sensor.

The amount of air going into the engine is calculated by the PCM using a Manifold Absolute Pressure (MAP) sensor which is mounted at the intake manifold. This MAP sensor measures the air density. Combined with outside air temperature and engine RPM the PCM calculates the amount of air going into the engine.

The idle control of this engine type is fully controlled by the PCM. The throtlle plate of the electronic throttle body can not fully close because it touches a springloaded adjustment screw. When idling the throttle plate is continuesly corrected by the electric throttle motor to obtain the correct RPM"

[JohnCh]

There are a lot of unused connections on current harnesses so that part is not a surprise.  Reading the thread linked from your other thread about the unused connector, it appears Caterham only uses the MAP sensor for barometric pressure in the Sigma (not air temp like in the Duratec), so its absence should not be an issue at your elevation.

 

-John

 

 

 

 

 

 

[wemtd]

Intermittent spark/wire fault? I had similar issue once with a frayed/worn wire going into ignition coil

 

[Deman USA]

thanks for this info.  ill take a look into it since the two harness attachment points are just sitting on top of the trans rubbing against the coolant sensor

[Deman USA]

incase anyone was curious I filled 3/4 of tank with 100 octane and 1/4 with 91 since that's the highest rubbish we get here in Arizona and it must of cleaned out the system or something because it now runs like a champ even on straight 91.

 

 

[Croc]

3 hours ago, Deman USA said:

incase anyone was curious I filled 3/4 of tank with 100 octane and 1/4 with 91 since that's the highest rubbish we get here in Arizona and it must of cleaned out the system or something because it now runs like a champ even on straight 91.

 

 

 

 

Sometimes these cars just have times of the month and you have no idea why things happen.  Glad it resolved itself for you.