Hi all, but of a head scratcher I’m after some help with… changed out the heater matrix on my jetta mk2 ( pierburg 2e2 ). Car was running fine prior but now has a lumpy cold start issue, sounds like it’s firing on 3. If you slightly keep you foot on the accelerator, after a minute the engine will settle and idle. Also the idle revs have now increased. Nothing has been touched except the matrix. Anyone had any random cold start issues like this?… any paths to look down would be appreciated.
Air lock in the water passage? Run the engine with the coolant cap off. I dont know much about carb cars but perhaps a water sensor is not picking up the true water temperature? But I may be completely wrong!
