Hi all.
I’ve a customer with a Peugeot 206 1.4 multi point kfx engine code with a magnetic marelli management system.
When the vehicle first came into us about a week ago it would not idle and misfired very badly. We carried out various test on the vehicle and replaced the spark plugs which where very black. The vehicle was fitted with an old boucoilie ignition coil which scoped ok. But we know all about the problems with these and decided to change it anyway.
The vehicle did not run a lot better.
There where and has never been any fault codes on the vehicle the whole time we have been working on it.
We then scoped the coolant temp sensor and it was miss ready from cold. The outside temp was 10 degrees and the sensor was reading 20 and the engine was stone cold. So it was replaced and the vehicle was still the same. Stalling and misfiring but now mainly from cold.
We carried out a compression test and checked the valve timing on the vehicle all was ok. Checked the inlet manifold vacuum which is 16 from cold and going upto 20 when warm. Tested the map sensor which is 339 mb at idle.
The injection duration was 4ms on idle.

So we decided to take the plunge and get a new ecu. The vehicle now does not stall but has bad misfire when cold which dissipates as the vehicle warms up.

We have rechecked every sensor on the engine and all the readings seem good.
Coil charge time 1.8 ms
Injection duration 4 – 4.3 ms on idle.
Injector resistance are all on 15 ohms.
Crank sensor good signal
Throttle position senor 0.7 volts to 4.7 volts with good smooth pattern.
Vacuum 16”hg cold 20”hg wam.
Knock senor working.
Idle control valve is get signal on all four wires.
The map senor is reading 309 mb at idle.
We have also checked all the earths and powers to he ecu and all seams good.
We have also checked all the earth that we can see in the engine bay and all are good.

The emission where high until the cat warmed up and then where all perfect.

So the vehicle has a new ecu, coil pack, spark plugs and coolant temp sensor and still misfires from cold!!

Any help on this vehicle would greatly be appreciated

Mike Field