Does anybody know anything about the injection pump on a jetta non turbo. I want to give it a little more fuel but I am unfamiliar with the pump. Is the extra fuel and heat going to effect the head. I have heard about cracked head problems.

 

Ja,the heads will crack. But this is pretty normal for them. Even VW allows cracks up to 0.6mm wide. So it is very common. Of course your head will crack easier if you hit the pedal without proper warm up.

But let me tell you these engines will run forever ( my non turbo Jetta had 300.000 miles on before I gave it away- because I was bored of it...
The extra heat will afflict the head. Turning in the screw won't give you more ommph, because air supply is still limited.
These cars are very cheap and reliable if you want to turn it up, you need the turbo version- and I say turbo version because adding a turbo will not last because you miss the oil jets cooling down the hypereuretic pistons( also missing) and the stronger rods and bolts
You can get 120hp from a 70hp turbo with intercooling and turning up the engine but you also need an oil cooler and and expect to change the head gasket every three months.
I know because I had a boosted turbo golf too.

The fuel screw is the single extra locked one. If you turn this screw- mark it and memorize how often you turned it in. Start with half turns. You won't recognize a lot power. Don't forget you raise also EGT's with turning up. Hotter EGT's means also prone to cracks...
Hey, this engine provides 54hp more than enough to hit the speed limit.

 

Thank You very much for the reply. I turned the only locked screw in before posting this thread and when I started the car it wanted to idle waaaaay too high as if the car was at half throttle so I backed it back out to where it originally was. This is my first non-american diesel and a whole different world than any truck.

 

Let me seek a picture to show you which screw must be turned.