'81 rabbit N/A surging idle

[i_d_k]

i have only owned the car for a couple of months and just now getting it to the point where it is daily driven. i read through a few threads, followed their advice, and did some routine maintenance with no luck. i replaced the fuel line from the filter with clear line (not seeing any air bubbles) and replaced the fuel filter.

when the car has just been started it idles fine but once you get on the gas the idle will not rest. i raised the idle to match the rev and it was way too high. the car is capable of running at a lower rpm; if there is a load on the engine like when you are in gear and coming to a stop, the idle will get low and is plenty smooth. however, once the load is removed from the engine the surging or bouncing begins again.

without tearing into the pump are there any other adjustments that can be made to try and solve it? the car drives great otherwise.

thanks in advance

[theman53]

The main fuel screw could be in too far. Check the FAQ for "make your 'x' car faster" Na, aaz or 1.6td for the x. There will be pics when you find what you are looking for. Could be junk in the pump, could be lots of things. If you can get some diesel purge and run that it may help clean it up. This is possible especially if the car has sat for a while. Good Luck

[i_d_k]

thanks! 

1st diesel, so there is quite a bit of learning to do. i appreciate the advice.

[fatmobile]

 Surging is cause by a loose IP mounting bolt.
 Maybe even one of those holding the IP bracket to the block.

[i_d_k]

ended up turning the fuel screw out about 1.5 turns and lowering the idle quite a bit and its running great. took it for a spin and i couldnt notice any difference in acceleration; so if there was any it was minimal. thanks again

[fatmobile]

Turning the max fuel screw out,.. aaand lowering the idle?
 That doesn't sound right. Usually one out the other in.
So were the RPMs hanging or going and stopping type of surging?

 Glad it's running good again!

[i_d_k]

the idle was probably around 1300-1400 before turning the fuel screw out. it was probably raised to keep up with the rich mix. the PO was driving the car without an air filter or cover and installed a giant exhaust. that was probably enough justification to dump in more fuel.

turning the the fuel screw out lowered the idle but it was still high so i backed that screw out also.