we have supplied and fitted a low mileage second hand 8 valve engine to this car, after the camshaft seized into the head of the original engine.
Runs superbly but P0300,random multiple engine misfire, comes on after a similar distance of about 1/4 mile.Clears but comes on again after same distance.
Engine came bare so swapped over camshaft and crank sensors etc. no fault code on original engine.
Have checked compressions, run and flushed engine.
Customer has had car back and run for 1 week and car hasnt missed a beat, but code still clears and comes on after about 1/4 mile.
We have checked speed sensor connections etc.
Any ideas appreciated
Andy