Hello everyone,thank you for allowing me to join, I have a ford Ranger 2.5 diesel 4x4 xlt, it has been a brilliant truck for years, but recently it has developed a strange misfire when starting from cold, after a short while and it runs perfectly. I have replaced the glow plugs,air filter and fuel filter I have cleaned the egr valve, and run some injector cleaner through the fuel system, but non have improved it. It is also strange to note that whilst it is running rough if I depress the clutch pedal instantly the misfire disappears, then release the clutch and it returns, I am confused.
I have a obd11 code reader and I bought a converter to plug it into the diagnostic socket under the bonnet on the passenger side but I didn't have any display on the reader at all, I do not know why it didn't work but I plugged it into my VW and that worked ok.
I would be very grateful of any input from anyone here who has some info that could help me.
Thank you for reading.

 

Changed the spark plugs and leads?

 

No I haven't as its a diesel but did change the glow plugs, but thanks for your reply.