Engine cutting out and pinking

[gulf 1]

My 2.0L duratec supersport R has started sometimes stalling while coming off the throttle and coming to a stop with the clutch in and out of gear, also I am noticing a slight pinking when the engine is under load.I don't think the 2 things are related but would be grateful for any ideas.If a remap is required am I right in assuming the ecu is locked.

[DJ.]

If it used to run well and has just started doing this then I wouldn't be looking at a remap. There are several possible causes, but I have had similar symptoms (from a different car) when the coil pack started to fail.

[SM25T]

Thought it was a coil pack on my k-series ... but it was the lambda sensor on the exhaust. Try unplugging the connector to it ... if it solves it, remove it and get the etched number off it ... order on line from motor factors quite cheaply.

[aerobod - near CYYC]

If it is pinking under load beyond about 2/3 throttle and 2/3 maximum revs, it isn’t likely to be the lambda sensor, as it should be operating open loop at that point.

It may be the TPS or wiring to it (I’ve just put in the 4th TPS sensor in my R400D, last one was unstable in output voltage and causing misfires in the first 10% or so of throttle, likely killed by vibration again).

Coil packs are definitely a possibility, along with the well documented wiring breaks if the upgraded harness is not used. Use an infrared thermometer when the engine is idling and check to see if the manifold / header from any given cylinder is colder than the other three, indicating a lack of ignition or fuel.

Could also be an injector or wiring to it, check with the thermometer to isolate a failing cylinder, then swap the coil pack to a different cylinder to see if the problem moves with the coil pack or stays with the injector.

Could also be a failing air or coolant temperature sensor, resistance values are generally available online to check the given sensor.

An MBE cable and a laptop will make diagnosis a lot easier if you can borrow or buy one, showing all the sensor, ignition, lambda and fuelling values to look for problems. The stock ECU (probably MBE 992) is locked, so needs a specialist with the ability to write to the ECU to remap, operating values and data logging can be done, though.

 

[Jim 123]

Are there any clues if you look at the spark plugs ?  What is the tick over engine speed on hot idle. I personally find the Caterham Rev counter not accurate below 1300 rpm.