Hi,

First post from a new member in the UK.

I recently fitted a Racechip RS to my 2017 JCW hardtop and I am impressed with the way it makes the car feel and it goes really well. The unit is set at the default setting of 4 and was purchased from eBay and was on another car that has now been sold since January 2019.

I noticed that sometimes during the coldstart phase the car ran lumpy and over the weekend it actually stalled which is something that it has never done in the past. I put this down to the fact that I run 99RON fuel so I changed the setting on the Racechip to 5 and the car went even better and I was really impressed. The problem is I still have the lumpy idle at some, but not all cold starts which is starting to annoy me. I checked all the cabling last weekend and all connections are fine and the unit is not getting water ingress as it is on top of the battery compartment and is dry.

This doesn't happen at every coldstart as sometimes the car is left overnight and is fine and I can't get to a definitive set of circumstances that the problem happens every time, for example each time it rains etc.

I can take the unit off and install the cap to revert to stock and see how that goes as it will point to a cabling issue and I can try to go normal spec fuel.

Does anyone have any ideas?

Many thanks

 

i would try the OE recommended fuel and see how that works.

Also a point of note, reach out to racechip directly with the serial number and verify that the software on your chip is in fact for the JCW. the cooper, cooper s, and JCW all have different software so since the chip was sold used, the previous owner may have been incorrect in saying it would work on your JCW. I have the GTS version on my 16 JCW and have had zero issues with it for the past year and 45,000km that i have had it installed. I run 91 Octane in the car with the occasional tank of 94 for on the track.

 

Hi,

Thanks for the reply.

I removed the RaceChip over the weekend by installing the blanking plug and still had the issue. I then when back to normal fuel and it seemed to get better as the ECU would have been re-learning what the car was up to fuel wise but there were still issues - I didn't give it that many miles TBH. I then removed the wiring harness and on the first start it was bad but I have now done a few hundred miles and the car is fine with no bad running on coldstart.

The unit is for the JCW as it says it on the invoice and the instructions in the box are for the JCW so I am sure it is the right one.

Its weird as it is something to do with fueling at coldstart as it was not consistent as sometimes it would start fine with no issues so I guess the ECU had learnt some new settings that were not suitable as now it is fine.

I will reach out to RaceChip and see what they say.

Many Thanks