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J888PRB
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420R misfiring

Hi All

My 420r picked up a misfire this week. On inspection it is cylinder 1 (front).

I've popped in new plugs - no change

popped on new coils - no change

now left scratching my head. Has anyone any experience of similar. Any advice welcomed.

Car is a 2016 420r - 13000 miles.

Thanks 

R400svn
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Id go for the wiring loom to the coils. 

ChrisC
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Yes, Friends 420R stopped firing one cylinder at a Trackday at the beginning of the year.  Swapped coil packs and plugs with no change in symptoms.   Loom connections all checked out ok.  Eventually diagnosed as the ECU coil pack driver.  MBE provided first class support, replaced the coil pack driver for a very reasonable charge. 

J888PRB
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Thanks everyone 

Running diagnostics check on it tonight.

I see Caterham sell the wiring looms direct so me point shopping around. Hopefully easy install?

2016 420R

Geoff Brown
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Local Duratec owner had exactly the same problem - No 1 cylinder. After substituting the obvious it was the ECU at fault.

John Vine
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I had exactly your problem on my 2008 R400D.  The cause was a fractured (brown) wire in the #1 COP connector.  It was difficult to spot at first as the fracture was partly obscured by the connector itself.  The cure was to fit the sub-loom (3AL080A).  I had to splice this into my main loom, but your 2016 loom may already come with a plug 'n' play Econoseal.

ETA: Some pics here.  And a bit of history here.

JV

J888PRB
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Spot on JV

the wire had sheared off in the connector. Bit of faff to isolate but great result that it was only this.

ordered the new loom (£44) and will fix the old one as a spare

as clearly yet another week link

 

im new to C7 ownership and can see already it will be a love-hate relationship.

 

2016 420R

John Vine
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Pleased to hear you've confirmed the problem!  Do you already have the Econoseal connector in your main loom?

The upgraded coil loom has fatter, silicone-sheathed wires, and is much more resistant to engine vibration.  Re your old loom, I'd suggest that the best place for it is the bin.

While on the subject of Duratec engine vibration, another weak point is the TPS (Throttle Position Sensor) loom.  CC supply a "race" version, also fitted with silicone-sheathed wires.  You may already have this, of course.  If not (and if CC are out of stock), it's not difficult to make up your own.

JV

J888PRB
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Hi John

Old coil loom repaired - still misfires but all 4 cylinders are working so all a bit odd., no longer isolated to cylinder 1.

Rather frustrating.

will try new loom when it arrives Thursday before freaking out. 
 

will look at tps next but none in stock as you say and beyond me to make one.....supposed to be driving to Spa in 6 days

Better warm up the M3

 

2016 420R

Geoff Brown
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And the Elephant in the room is....the ECU !

Geoff Brown
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And the Elephant in the engine bay.........the ECU !