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.
How the auto-choke feel during startup? It should get very hot quickly. If theres airlock in the coolant system (common issue as air gets trapped behind the thermostat) then you might not be getting a good coolant flow to the autoc-hoke and therefore not initiating the correct coldstart procedure for the Pierburg. Id also take off the airbox and have a look at what the choke is doing during startup. Not sure how the temp is where you are, but here in Norway is fucking Baltic atm so the choke start completely closed and then as the ignition is turned the auto-choke heater gets power and slowly opens the choke (alongside the pulldown unit). Coolant flow then hits the bimetallic spring and opens the choke further so you dont get too much lumpy bumpy. Id definitely have a read through the FAQs on the pierburg and the troubleshooting guide ive just written, lots of good info there.....it sucks but it really is best to go through it all methodically otherwise you get tied up in knots. Let me know how the cold start procedure looks!
