Outer Limits 4x4 Board

As well as the GQ I also have a L28 SWB Patrol. Recently a sound has occured. It is a high pitched whistle almost like a turbo (i wish). It seems to be constant except when opening the throttle and the motor also idles rough and hesitates without the choke semi-closed. To me it sounds like it is sucking on the intake side. I have had the air-cleaner off and it soounds to be coming from the backside ie. closest side to the engine) of the carburettor. My guess is either the gasket between the carby and manifold has a leak or between the manifold and the head. Hopefully i do not neeed to repair the carby?? What do u guys think??

Thanks

Sounds like a vacuum leak, when opening the throttle vacuum drops, therefore no noise.
Did it just happen suddenly? or slowly get worse?
Before checking intake manifold gaskets and carby i'd look at all of the vacuum lines running off of the intake manifold - e.g. brake booster lines e.t.c., could remove them from the manifold one at a time with the motor idling, then stick your finger over the fitting on the manifold, if you get no noise on one then that may be the problem.

The noise is slowly getting worse and accordingly the motor is progressively running worse.

vaccum leak for sure. i've got one on the intake manifold just can't be stuffed fixing it

Simple test for Vacuum leaks.......

1:
Remove aircleaner......
Start motor and get it to idle as best as possiable....

2:
spray "Areo Start" around suspect area ......
( a piece of tube placed over the carby will stop any excess from entering the motor through normal induction )
If the engine increases its RPM and/or idles smoothly, you have a leak.

The Areo start is sucked in through the leaking area and then into the motor, its this added fuel which compensates for the leak.
LPG from a BBQ bottle does a similar thing ( use regulator and a hose),
In sheer desperation I have used accetelene but wouldnt recemend it.

Kingy

JUST put some oil along the intake manifold that way you wont blow your self up

my new patrol has a similar problem, i just sprayed some carbi cleaner on and around the carbi and found the leak, where is all was dryed up almost before it hit the surface of the carbi, but was wet everywhere else.
I just have to replace the bottom crabi gasket where it connects to the inlet manifold

i had a similar problem on a standard carby they have a ceramic spacer between the carby and the inlet manifold these crack very very easily no matter how much you try you cannot seal this leak without replacing the spacer and they are rare as a flower shit as are complete factory carbies for the l28 i hunted for months b4 buying a complete motor with factory carby then i was happy lmao