Talk to Lewis Hamilton, he had the same problem in Mexico and said `The track was much higher up than we expected, we thought it was at sea level but it wasn`t and it made the motor misfire`.. *silly*.....Sorry!
Is yours a variable or fixed cam engine?
Is the air filter clean?
Any manifold air leaks ?
cold and wet needs more fuel so if it`s lean to start with it will get leaner.....chug...chug!
The car went back to Caterham Gatwick under warranty last week. Apparently the problem is due to the catalytic converter breaking up. The car has only done 3.5k miles so I am slightly surprised. It will be interesting to see how it runs after the cat is replaced.
Usually a cat break-up is due to running too rich of a mixture for too long. I would ensure that the cause of the break-up is identified, as it is very uncommon at such a low mileage unless the converter has suffered a very significant mechanical shock.
Did CC offer any comment or explanation about what may have caused the cat damage? Cats aren't cheap, so I'd hope that they didn't simply replace it without a lot of investigation. For example, did they say anything about the lambda sensor?
Do you happen to know whether the cat was fitted continuously throughout the car's Academy life, and does the 3.5K miles include all the track usage? Indeed, was the cat the same age as the car, I wonder? I'm even wondering whether the lambda sensor has been faulty throughout your ownership, leading to continuous over-fuelling.
You are right, cats aren't cheap looking at the price on the Caterham parts site. I'm glad they have agreed to cover this under warranty. The car did the Academy followed by a few track days so I think the mileage is about right. I don't know whether the cat is the original. I will ask CC the relevant questions when they confirm the availability or otherwise of a replacement.
CC have no cats or decat pipes in stock and don't know when they will receive any. Apparently it is not totally unheard of for a cat to fail in a race/ex-race car due to 'hard use'. They will look for any underlying cause when the car has a properly functioning exhaust system.
To update this thread, Caterham replaced the cat and air filter and I collected the car. It seemed the same on the road but I had a track day booked at Goodwood so took it there for more thorough testing. It was possibly slightly better but still rough at light to moderate throttle around 3 - 4000 rpm. I was a bit disillusioned with it and Caterham at this point and contemplated selling the car. It would have to go to a dealer as I couldn't sell the car privately in this state with a clear conscience.
Then I spoke to Steve Greenald of Two Steves fame. He seemed interested in the problem and after I had purchased the MBE can adapter and installed easimap on my laptop provided me with an ec2 setup file that was appropriate for the 959 ecu fitted to my car. He looked at the log files and made a few suggestions. It was at this stage when I was operating the throttle pedal by hand, crouched over the side of the car peering at my laptop, that I realised the throttle was quite stiff and "sticky". I disconnected the cable and operated the mechanism at the throttle body, which was very stiff. I loosened the tps and the action of the throttle suddenly felt free and normal. Clearly the tps had been overtightened or misaligned. The cover plate had been bent by the screw heads.
I fitted a new tps, being very careful to get correct alignment and not overtighten. New spark plugs went in, I sealed the leak at the 4:1 collector with Permatex Ultra Copper sensor safe sealant and replaced the lambda sensor. I checked for vacuum leaks on the induction side but couldn't find any. I then spent ages setting up the throttle stop and tps position.
On the road the car has been transformed. It now works as I would expect. There is no hint of the rough running, the kangaroo effect has gone, idle is steady and overall I am really pleased with it. It is a shame it didn't run like this when I bought it. I said at the time that I couldn't believe they all ran this badly but I was assured that they do. It's not true. I am glad I persevered.
****
Notes
Caterham were out of stock of the tps, plugs and lambda sensor so I purchased from alternative sources for around half the price.
Plugs NGK TR5B-13 from Euro car parts £12.36 for the set.
TPS came in a bag labelled Jenvey TP1. It is a Colvern CP17 and appears identical to the original.
The lambda sensor was a problem. The Bosch catalogue doesn't include 0258006600 which is the type no on the original sensor. I fitted a Bosch 0258006155 This has a similar body to the 600 but slightly fewer larger holes at the business end. The strain relief is slightly different, the lead is about 2cm longer but the wiring and connector are the same. It was about 1/3 of the cost of the Caterham specified part and seems to work.
#10:
Thanks, James.
For us MBE folks, does an OBD scanner offer anything that Easimap doesn't?
JV
Hi John, I don't think an OBD scanner will give anything from the MBE 9A4 or 992 ECUs that Easimap can't display.
James
Talk to Lewis Hamilton, he had the same problem in Mexico and said `The track was much higher up than we expected, we thought it was at sea level but it wasn`t and it made the motor misfire`.. *silly*.....Sorry!
Is yours a variable or fixed cam engine?
Is the air filter clean?
Any manifold air leaks ?
cold and wet needs more fuel so if it`s lean to start with it will get leaner.....chug...chug!
3500 is where it starts to `get on the cam`
Thanks, James.
JV
The car went back to Caterham Gatwick under warranty last week. Apparently the problem is due to the catalytic converter breaking up. The car has only done 3.5k miles so I am slightly surprised. It will be interesting to see how it runs after the cat is replaced.
Usually a cat break-up is due to running too rich of a mixture for too long. I would ensure that the cause of the break-up is identified, as it is very uncommon at such a low mileage unless the converter has suffered a very significant mechanical shock.
James
I agree with James.
Did CC offer any comment or explanation about what may have caused the cat damage? Cats aren't cheap, so I'd hope that they didn't simply replace it without a lot of investigation. For example, did they say anything about the lambda sensor?
Do you happen to know whether the cat was fitted continuously throughout the car's Academy life, and does the 3.5K miles include all the track usage? Indeed, was the cat the same age as the car, I wonder? I'm even wondering whether the lambda sensor has been faulty throughout your ownership, leading to continuous over-fuelling.
JV
You are right, cats aren't cheap looking at the price on the Caterham parts site. I'm glad they have agreed to cover this under warranty. The car did the Academy followed by a few track days so I think the mileage is about right. I don't know whether the cat is the original. I will ask CC the relevant questions when they confirm the availability or otherwise of a replacement.
CC have no cats or decat pipes in stock and don't know when they will receive any. Apparently it is not totally unheard of for a cat to fail in a race/ex-race car due to 'hard use'. They will look for any underlying cause when the car has a properly functioning exhaust system.
All a bit frustrating.
To update this thread, Caterham replaced the cat and air filter and I collected the car. It seemed the same on the road but I had a track day booked at Goodwood so took it there for more thorough testing. It was possibly slightly better but still rough at light to moderate throttle around 3 - 4000 rpm. I was a bit disillusioned with it and Caterham at this point and contemplated selling the car. It would have to go to a dealer as I couldn't sell the car privately in this state with a clear conscience.
Then I spoke to Steve Greenald of Two Steves fame. He seemed interested in the problem and after I had purchased the MBE can adapter and installed easimap on my laptop provided me with an ec2 setup file that was appropriate for the 959 ecu fitted to my car. He looked at the log files and made a few suggestions. It was at this stage when I was operating the throttle pedal by hand, crouched over the side of the car peering at my laptop, that I realised the throttle was quite stiff and "sticky". I disconnected the cable and operated the mechanism at the throttle body, which was very stiff. I loosened the tps and the action of the throttle suddenly felt free and normal. Clearly the tps had been overtightened or misaligned. The cover plate had been bent by the screw heads.
I fitted a new tps, being very careful to get correct alignment and not overtighten. New spark plugs went in, I sealed the leak at the 4:1 collector with Permatex Ultra Copper sensor safe sealant and replaced the lambda sensor. I checked for vacuum leaks on the induction side but couldn't find any. I then spent ages setting up the throttle stop and tps position.
On the road the car has been transformed. It now works as I would expect. There is no hint of the rough running, the kangaroo effect has gone, idle is steady and overall I am really pleased with it. It is a shame it didn't run like this when I bought it. I said at the time that I couldn't believe they all ran this badly but I was assured that they do. It's not true. I am glad I persevered.
****
Notes
Caterham were out of stock of the tps, plugs and lambda sensor so I purchased from alternative sources for around half the price.
Plugs NGK TR5B-13 from Euro car parts £12.36 for the set.
TPS came in a bag labelled Jenvey TP1. It is a Colvern CP17 and appears identical to the original.
The lambda sensor was a problem. The Bosch catalogue doesn't include 0258006600 which is the type no on the original sensor. I fitted a Bosch 0258006155 This has a similar body to the 600 but slightly fewer larger holes at the business end. The strain relief is slightly different, the lead is about 2cm longer but the wiring and connector are the same. It was about 1/3 of the cost of the Caterham specified part and seems to work.