Sagaris engine problem - Can't seem to find the cause

Sagaris engine problem - Can't seem to find the cause

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Tom74TVR

Original Poster:

169 posts

157 months

Wednesday 23rd April 2014
quotequote all
Hello,

to get straight to the point, when I put my foot down in any gear except first my engine starts stumbling and shuttering like it is drowning in too much fuel. It takes a few seconds before the engine finds his breath again and starts accelerating.

I have had the car looked at and what we can see is that there is a big difference between the data from the lambda sensors and trottle possition sensors on the two banks. But we cannot find the reason for this.

Also in the adaptives file of the ECU you can see that one bank fluctuates a lot more than the other bank.
Same thing with the throttle position sensors... the one at the front fluctuates all the time while th eother is stable. Same for the lambda readouts... one stable, another not.

I do not get any sensor errors and we have tried to change the lambda sensors but nothing worked. I am not sure if this is correct but for me a sensor works or it doesn't work.
I also had the mass checked out and put in some other extra cables but this is not the issue either.

Does anybody have an idea how I can best tackle this issue?
Thanks a lot.
Tom

Tom74TVR

Original Poster:

169 posts

157 months

Saturday 26th April 2014
quotequote all
Hi,

It seems my issues are caused by the lambda sensors. We could see when we measured the exhaust gas that the CO2 levels were much to high. At some point the lambda sensors would work and CO2 levels would drop but only for a few minutes.

We had a look at the sensors and it seems they were very badly installed. We had to use a lot of heat to get them out but as they were positioned incorrectly in the factory we could not get any new ones in....

We also put in a etra mass cable from the lambdas to the engine block.

We hope to have the car back together later today to see if it fixed.

Thanks for all the suggestions.
Tom.

Tom74TVR

Original Poster:

169 posts

157 months

Saturday 26th April 2014
quotequote all
With both lambda sensors replaced it drivers again as it should.
Thanks again for the tips
Tom.