New 420R won't idle cold

[mike150]

Problem...........................

My 400 mile 420R won't idle until it has at least 45 deg on the gauge and I live no where near a Caterham dealer. I have turned up the idle a little to sit a 1200rpm when hot but the car needs a constant light throttle until it gets up to 45deg and it's a pain.

I have tried to get talking to someone in Caterham about it several times but either I can't get them or the relevant person is to get back to me and they never do. Williams automobiles that I bought it from is telling me all the 420's do this and it's normal. I don't think it can be normal, I've never seen any modern 4 stroke engine that won't idle cold least of all a near 40grand Caterham.

Can anyone off advice in the way of what to try or who to speak to in Caterham?

Thanks.

[Jonathan Kay]

Previous similar experiences and hints.

Jonathan

[John Vine]

I think the first thing to say is that it's not normal.

As for the cause, it could be one of several things, or a combination, and very tricky to diagnose at a distance:

1. Map -- not providing sufficient cold enrichment
2. TPS -- not set correctly
3. Lambda sensor -- normally operates at 60C+, but might be faulty
4. Wiring -- poor earths, dodgy connectors
5. Throttle butterfly -- could be set too low (but already you've tried opening it up a bit)

I think you may well have problems resolving this without the use of diagnostic tools (Easimap and an MBE lead).  In other words, it's one for CC or Williams, especially as the car is under warranty (which too much poking about might invalidate!).

Personally, I would insist that Williams or CC collect the car for investigation and fix.

JV 

 

[mike150]

I live in N.Ireland so I can never see Caterham or Williams agreeing to collect the car!

Williams tell me Caterham are telling them its normal on a 420, sounds a lot like BS to me.

I have read there are a few others with a 420 having the same issue.................

[John Vine]

I live in N.Ireland...

Yes, I can see that might pose a problem.  What dealer/agent support is available in NI?

Just a thought...

When you first start the car, do you press the accelerator pedal at all?  If you do, it's quite easy to confuse the TPS.  The solution is to reset it by switching the ignition on and off several times.  And if you adjust the throttle stop, you need to then reset the TPS the same way,

JV

 

[mike150]

There is no dealer agent in Ireland never mind N.Ireland.

I'll try the reset as I do press the accelerator to start the car as I have to otherwise is fires and stalls within a second.

Thanks,

Mike

[Jim 123]

I think the Handbook advises that you should not touch the throttle until after the engine fires up.

[mike150]

That's a good idea but if I don't touch the throttle it won't fire up.

I am hoping Caterham come up with a few suggestions or parts, there are a few other 420 owners are experiencing the same thing and I believe they live a lot closer to a dealer or Caterham themselves than me so if a solution can be found for them the same solution might solve mine not idling.

[John Vine]

but if I don't touch the throttle it won't fire up.

That's definitely not right. It should start with no throttle input at all, and then settle down to a steady idle at 900-1000.

JV

[ScottR400D]

My 2015 R400 would never idle at 900/1000 until I had RBTBs fitted. In original form it hunted between 1100/1400 and was easily stalled, moving off. 

When the RBTBs were fitted I was told that the barometric pressure/air temp sensor hadn't been working but whether that was the cause or not I don't know. I also had a better TPS installed at the upgrade. 

Idles steady at 950 now and pulls away very nicely, you can even move off at tick over. F

[Mucus72]

I can't really help with your problem resolution, but I assembled my 2016 420R and it fires fine from cold. I don't touch the throttle when starting and it settles to fast idle immediately. CC or Williams is 100%  incorrect here! It's a Mondeo engine from a bunch of years back. 

[griffchris]

Ditto, definitely not normal on a 420R.  FWIW, the ECU supplied with my kit (self build) was faulty and had to be replaced at PBC so they have form on this......

[John Vine]

I also had a better TPS installed at the upgrade. 

Do you mean the race TPS sub-loom, or is there an alternative TPS to the standard Ford item?

JV

[ScottR400D]

Not exactly sure, but I think the race sub loom. 

[John Vine]

That makes sense. Thanks.

JV

[ScottR400D]

Why's that John? I must admit, with this one I just left it to Luke Stevens who did the work and the car was set up on his rolling road by one of the two Steves. 

Very pleased with the results though. You wouldn't think it was only 10bhp more the car is so much more responsive, plus easier to drive, idles better and sounds much better!

[John Vine]

Well, the obvious (and recommended) Duratec TPS upgrade is to fit the race sub-loom, as it's a very effective cure for the problem of fractured TPS wiring. 

So, when you said "I also had a better TPS installed at the upgrade", I simply wondered whether you'd had an alternative TPS fitted.

And I'd agree that the RB upgrade produces some very attractive results.  CC fitted mine back in late 2014, and I was very pleased with the combination of performance, faultless starting, smooth idling, and excellent road manners when making progress.  One thing I haven't considered is to get the Two Steves to tweak the map, as the one CC installed seems to work just fine.  Mind you, they did a great job with my plenum-induction version a few years back.

JV

[ScottR400D]

Ahh, I see. I never questioned the TPS upgrade, Luke seemed to take it for granted that I'd want it, so I just left it to him! What you say makes sense.

 

 

[Manstein]

Is the sub loom a Caterham or Ford part?

Thanks

[John Vine]

It's a CC part (30L117A).  It includes the standard Ford TPS, into which are potted three silicone-sheathed wires (black, white, red), with a 3-way male Econoseal connector at the other end.

It's a tad pricey, but it's possible to make your own.

JV

[Martin J]

https://www.youtube.com/watch?v=Eq21xDJq7Ac

This one doesn't want to idle cold either.

[mike150]

I had seen that video, there are some that are fine and some that won't run until warm so Williams telling me its normal is incorrect.

[mike150]

I've waited a while to respond again but firstly may I say thanks for the PM's and the information on the thread.

After this thread that was picked up by nice chap that helped me out with Caterham, they asked that my ECU be returned for analysis, that was nearly 3 weeks ago and I am still waiting on an answer as to what the issue is never mind getting it back.

Currently............... an unhappy Caterham owner..................but hopefully that will change this week.

[ChrisC]

A little gem I discovered this weekend about my R spec Tacho.   I have a 360R which I put on easymap to discover the Tacho was over reading. Easymap said 950 to 1000, but the Tacho reads 1150-1200.  If I dropped the revs based on the Tacho I would expect to have problems with the cold idle.

[mike150]

Interesting however the hot idle on my car seems fine, in my uneducated opinion my car has no cold map in the ECU or its not being called on by the lamda sensor.