Hi all!
I’m new here and I came for a little help. Maybe someone experienced the same simptoms.
Recently my T5 wagon developed unusual things. First off, when I start the car for the first time, it gets warm easily in a few minutes and runs absolutely great without any problems. I can drive it to the moon and back if I don’t have to restart it. The torque is great, and runs like a dream on higher rpms as well. But when I restart it, it starts acting up, little cuts and breaks when accelerating hard, without any warning lights. ( didn’t notice any change in boost pressure) If I drive it smoothly there are no simptoms at all. Only when accelerating hard, maybe sometimes a verry little rough idle but nothing too serious. First time I had around half a tank maybe a little bit less when it happened. It started acting up after the first start of the day. So I went to a gas station (fuel: OMW maxxmotion 100octane) and filled it full. After I filled it fully, i started the car, got in tested if it lags,cuts, or does anything wrong when accelerating and it didn’t! I thought okay, probably a fuel related problem, but since then it always does the same after starting the car when it’s already warm.(even with max fuel) If i let it fully cool, and I start it, goes great without any problems. Until I don’t have to turn off the engine again, and start it up warm. Any ideas? Any help will be appreciated!
Thanks!

 

have you tested the ECT sensor? You may want to replace the thermostat, sensor and overflow cap just for maintenance if they are over 5 years old. Have you measured fuel pressure with both a cold and warm start? should be about 39-40 PSI. you'll see a shrader valve on the end of the rail, just rent a guage from Autozone and watch RobertDIY's vid.

 

Thanks for the tips! The ECT sensor, thermostat, and the overflow cap are brand new! In fact all water/vacum lines are brand new. I have not tested the fuel pressure yet, but I will and I’ll report back.