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Hi guys, I'm from the RS Liberty club, I have a 1.8L '87 Brumby as a run around while I'm looking for another Liberty but it's running really bad. The guys from the RS club suggested I try here for some help. Keep in mind I don't know much about carbys as this is the first one I've worked on.

The Brumby uses heaps of fuel (over 15L/100kms in a 900kg car!) and pretty much won't drive without the choke on, which is probably part of the reason it uses so much fuel.

The only stuff I know about carbys has been learnt since I got this car but I have a friend that knows a bit, we put a gasket kit through it and a new plunger and cleaned the jets and all that sort of stuff but it didn't help. I've also done an oil change and replaced the fuel filter. The timing was advanced about ten degrees too much and we think this is because the vacuum advance isn't working so the last owner advanced the timing to make up for it (the previous owner was the dumbest lowlife piece of sh*t I've ever met).

The secondary butterfly (I think that's what it's called) doesn't seem to be opening when revving the car and there doesn't seem to be any vacuum getting to it. We think there's a vacuum fitting blocked inside the carby that both the vacuum advance and secondary butterfly are run off. If we hook them both up to a normal vacuum line we can see the butterfly open right up and the car instantly revs it's head off so we're guessing the vacuum fitting has some sort of valve to control the amount of vacuum. We tried blowing the vacuum fitting out with compressed air but that didn't work.

Can anyone help? Is this a normal problem and does it sound like a blockage? If so is it likely that we would be able to get to it to unblock it if we pulled the carby appart?

I got prices on some carbys from wreckers but they were $80-$95 which I don't want to spend if I don't have to especially considering they may have their own problems. Any help would be much appreciated.

The hitachi carby's are pretty straight forward to work on, as long as your using a clean work surface and are paying attention when you pull it apart you should have no issues putting it back together.

To me it sounds like the timing is too far retarded, 12 degrees advanced is good if you're running a 98 octane fuel or stick to 8 degrees if you're using normal unleaded.

Actually after some more thought, it sounds like a vacuum leak rather than a blockage, this is why you need the choke to keep it running, as it's getting too much air and running lean.

Before you take the carby off check all the vacuum hoses and T junctions, also if the vacuum advance isn't working as you say it could be a hole in the diaphragm.

To test the hoses start from the manifold and carby and remove the hoses one at a time, block the opening with a free digit, if the engine improves theres a good chance you've found your culprit but there could be more than one.

Jordan.

The timing is advanced 10 degrees at the moment and I've tried running on both 98ron and regular unleaded. I originally thought vacuum leak too as it makes the most sense but I couldn't find one and I've replaced a few of the older looking vacuum lines but will get around to replacing them all.

I still don't understand why it would be using so much fuel, the tailpipe is very sooty. Maybe it's just from running on choke but if the car is running lean without it then the choke shouldn't make it that rich. I'll have another look at the vacuum lines then pull the carby appart again.

spray WD40 type stuff around inlet manifold to head join, without choke on. spray oil burns like petrol in a way and makes up for the air leak, so engine revs would change if you found this spot to leak. Brakes ? good ? not suckn air from booster ?

Thanks, I'll give that a go. The brakes seem fine.