Pierburg problems

[Dougie88]

Hi can anyone help? I have a 1988 bus , the problem I have is when I start the engine it runs fine but if you open it up to full throttle, it's sounds like it is not getting enough fuel but if you look down the second choke the fuel is spraying in from the lower jet and top jet, may be little to much. I hope someone can shine some light on this cheers.

[kevtherev]

Which hole are you looking down



round or square

[itchyfeet]

Is this just a sound when stationary and reved or do you have problems driving?

Assuming when driving, check the second choke (round) is opening properly?
it opens by vacuum after the throttle is open sufficiently, you can prop the throttle open with a brick, then pull the pipe from the rear of the carb that goes to the vac unit, suck on rhat pipe and check the throttle opens.

Fuel starvation can also be a blocked jet or blocked filters or vacuum leak may stop the second barrel opening, lack of power can also be ignition.

so need to understand the problem better to help with a solution.

[Dougie88]

It's the round one.

[Dougie88]

This problem is when stationary, as it has no mot at the moment. You can see the second choke open when on full throttle.

[kevtherev]

Hi can anyone help? I have a 1988 bus , the problem I have is when I start the engine it runs fine but if you open it up to full throttle, it's sounds like it is not getting enough fuel

As itchy suggests this could be a timing advance fault.
use a timing gun to eliminate this, it should climb to 30 deg BTDC when full throttle is selected

be sure there are no induction leaks as suggested, the amount of fuel sounds about right, these old ladies drink the stuff at full chat

[itchyfeet]

Well I wouldn't worry until you drive it, revving hard when stationary isn't a good test
if it sounds odd could be ignition related and not fuel.

http://syncrosport.com/sthwark/syncro/m ... E3-2E4.pdf" onclick="window.open(this.href);return false;

[kevtherev]

Hang on... do you have the rotor arm rev limiter fitted?

[itchyfeet]

opening it up long enough stationary to hit the rev limit is just pointless and likely to cause engine damage, wait till you drive it and open it under load.

[Dougie88]

Cheers I will check the timing and take it for a run. Thanks for your help. I will let you all know how I got on tomorrow.

[Dougie88]

I had a run in the bus today,and it seems to run fine but it does puzzle me why it will not run on full revs when stationary.

[kevtherev]

did you check the rotor arm?
is it the restricted type?

[Dougie88]

It's has a standard rotor arm. I'm going to repair the exhaust and then check the timing,and then check it again.

[itchyfeet]

Check tge dizzy vac advance unit works, it should be seen moving the rotor arm when you suck on the pipe, you do have to suck hard.
then stop revving the nuts off it stationary

[Dougie88]

Check tge dizzy vac advance unit works, it should be seen moving the rotor arm when you suck on the pipe, you do have to suck hard.
then stop revving the nuts off it stationary

Thanks I will try that.