620s

[Paul van]

Just bought a new620s.  What a machine.    But at idle the engine hunts from 1000 rpm to 1600. Is this normal on a620 ?   Can anyone advise.   Never had the issue on my previous cars 

[Titanium7]

Not normal.

 

[Golf Juliet Tango]

I would not accept the engine hunting.

[Mark w]

Not normal , my 620(R ) sits rock solid at idle .

I would take it back to the supplying dealer .

Alternatively ,where are you based ? If your local i am happy to plug it into easymap and check that the TPS is set correctly . They are sensitive to being set up to flow the correct amount of air at idle whilst also being at load site 0 on the map . 

I would also check that the throttle cable has a tiny bit of slack at idle so its not stopping the throttle fully close , for instance when hot ..

 

 

[Paul van]

Many thanks for the advice I didn’t think it was correct.  The dealer told me it was normal on a 620. ! 

 

Ill get it checked out 

[7 wonders of the world]

I assume that was one of the Caterham dealer network...?

How can they do that.... a customer spends a not insignificant sum on a car a straight away they pass off an obvious fault as normal.... shocking      

[Titanium7]

My 620S from cold runs for a short while at a slightly higher rpm and then drops down once things start to get warm, i assume the map has been written this way.

[John Vine]

The dealer told me it was normal on a 620. ! 

I think that would qualify as the mis-diagnosis of the year!   Can you tell us who the dealer is?

JV

[NASHMAN600]

My 620s had the same symptoms as yours the TPS as Mark W Suggests is most likely way out.

Mine was at 60% throttle at idle..

My tps is on its 3rd adjustment.

Sadly IMHO.. Due to this and overfuelling my car with 3122 miles has 4 very badly scored Bores.

It has gradually got noisier on startup and sounds like a ring is broken when warm and cruising.

It is now parked up with 3122 miles, no track days.!

I may be just unlucky,

So it is not correct, get it sorted ASAP.

 

 

[Alan Reeves]

Nashman, how does  overfilling give scratched bores, I’m assuming overfilled with engine oil.

 

[John Vine]

Bore wash, perhaps?

JV

[Mark w]

over fuelling , not over filling 

[7 wonders of the world]

Why the hell cant CC sort a decent map for the cars they sell....?

There was a comment a while back on here from a CC tech that the 'map was very rich' couple this with the poor running in advice they insist on I'm surprised they arent replacing 620 engines every week.

Come on CC this isnt rocket science......

[Mark w]

Whats wrong with the map ?

My 620 was built in spring 2014 , never had an issue with the map .

[CtrMint]

Evening.

I'm going to be that guy, but I am trying to be helpful.  I picked my 620R two weeks ago.  I'm amazed at how steady the idle is when cold or hot, it doesn't hunt at all.  The car instantly fires too, like a normal modern car, totally different to my 420.  The car does idle at 1100, which slightly high, though might be inaccuracy from the tacho.

Assume both cars are of the same generation/era I'd say something is definitely different to mine.

 

[Mark w]

For those that are interested I have found that the best set up for my car is to set the TPS at 0.45v with the throttle fully close and then wind it open to 0.57v to give the correct air flow at idle and to correspond with load site 0 on the map 

It's been suggested that the factory settings are 0.40v and open to 0.54v but I've found that flows too much air for a 900-1000 rpm idle and it also sets the closed throttle position below the first load site on the map meaning that you have to open the throttle 0.03v on the TPS before the TPS map has any effect .