Hello, I am new to this forum and hoping to get some advice. I have been an auto tech for more then 30 years. I mainly worked for GM, so VW’s are a whole new world for me to work on. My daughter just got a 99” Beetle 2.0L 5speed. The car runs real bad cold and after it worms up it hesitates on acceleration. So far we have replaced the spark plugs, the coil pack, fuel filter, fuel pump and fuel pressure regulator. I have read a lot of post and most of all of you have the same issues. If I put a pair of vice-grips on the fuel return line just after the regulator, all my problem go away. Cold start, rough running and hesitation all disappear. Now I know that I can’t continue to run the car like this, even though I would like to, it’s not healthy for the plastic fuel rail. To give you a little history, we have had codes for misfires, injectors and O2 sensors. I have cleared the code and they haven’t returned, even with the engine running the way it is. I just cat put my finger on it. With the vice-grips on the return line, that little beetle runs like a scalded dog! So I know mechanically the engine and drive train are ok. I am going to clean the MAF sensor and the throttle body today and put an inline fuel pressure gauge to see the pressures as it runs down the road. Any suggestions or comments are welcome; I am at whit’s end with this little car!