Bosch pump setting advice

[simonh]

Just looking to double check that I'm doing the right thing here.

I have a Bosch (9mm) pump fitted now and the car is running pretty smoothly but way slower than with the Lucas setup which I'd spent ages playing about with. I'm happy that everything's working ok so want to make it faster again.

I've adjusted everything I can to get the throttle to open as far as possible and have fitted a ground LDA pin and turned the spring seat up by one full turn to increase the pressure slightly. Is it now just a case of turning up the max fuelling until it starts to smoke? I've seen a couple of mentions of turning the screw at the very top of the pump (the one with the locknut above the lda pin) but I'm not sure what this does.

Thanks for any help!

[Tom]

The screw on the top needs to be all the way out, so the lda pin can move up as much as possible, if you've took the top of the pump off its easy to see when its flush with the "top hat". Got a boost gauge? Winf the max fuel up until it starts to smoke when your flat out in say 4th gear. Then back it off a bit, should only be a wisp of smoke.

[simonh]

Thanks Tom. I have a boost gauge fitted. It was holding a steady 1.7 bar with the Lucas. With the Bosch bolted on as supplied/ standard it was peaking at 1.25 bar and felt healthy but pretty 'flat' (and really clean!)

Looking forward to the drive home tonight. Can tell it's going to be pretty cold so the top mount wont be holding it back as much as usual.

It's only running a standard K14 but it might be worth doing the governor mod anyway. One step at a time though.

[Tom]

Once you put some more fuel in it'll make all the difference!

[simonh]

I now understand! "turning the lda out" part quite far down on the setup guide is what this was referring to. Knew it had to be there somewhere but hadn't made the connection. So simple. :-)

[simonh]

It's made a massive difference. Ran the idle stop screw nearly all the way out and turned up the main fuelling until the idle speed was just under 1000rpm. I've ground the arm so it has much more travel so I can move it round a spline if necessary to lower the idle. It's faster than before and doesn't need delicate throttle control any more to keep the smoke at bay when pulling away. Brakes now feel terrible though. Need to get the GTi calipers cleaned up and fitted.

Is it possible for it to travel too far at full throttle as the arm is currently on the standard spline but can travel way beyond the normal full throttle position.

[Mattcheese31]

It's made a massive difference. Ran the idle stop screw nearly all the way out and turned up the main fuelling until the idle speed was just under 1000rpm. I've ground the arm so it has much more travel so I can move it round a spline if necessary to lower the idle. It's faster than before and doesn't need delicate throttle control any more to keep the smoke at bay when pulling away. Brakes now feel terrible though. Need to get the GTi calipers cleaned up and fitted.

Is it possible for it to travel too far at full throttle as the arm is currently on the standard spline but can travel way beyond the normal full throttle position.

yes it is, if you press too hard with your right foot you could fcuk the govener inside the pump . . .

[simonh]

Good to know, thanks. I'll slide the cable along the arm a bit so it can't move so far round.

[Mattcheese31]

Good to know, thanks. I'll slide the cable along the arm a bit so it can't move so far round.

find where full throttle is and and use the stop screw if you can, be shit if you snapped the gov cradle . .

[Matt]

Snapped gov is shit had it happen to me, ended up being a new pump as the gov went missing inside!

[simonh]

Maybe a silly question but how do you find out where full throttle is?

[Mattcheese31]

Maybe a silly question but how do you find out where full throttle is?

just pull the throttle arm round as far as it will go, you'll feel a little resistance towards the end as you hit the governor . .

[simonh]

It's all so simple when you know how! Thanks again.