High Pitched Whistling

[nathan.leber]

I've got a bad noise coming from my 94 4WD TBI, The best I can
describe is a real high pitched whistling/screaming sound. It fluctuates
acceleration. I pulled the air filter off because I thought it sounded like
some kind of air leak. It sounds like it's coming from right around the
throttle body when I'm looking under the hood. The pitch changes when
I hit the throttle, and it will stop if I put my hand up under the injector
to block the fuel. Anyone know what this is?

[spideyjected]

Bad Injector?

[lucy_blue_93]

^^^yea...what he said

[Big Mack Daddy]

it could also just be clogged and the whistling is coming from the fuel trying to pass. while it is running check to see if there is a nice pretty cone shape coming from the injectors. if there isnt either the injector is dirty or bad. before you replace an injector, run some lucas injector cleaner and see if that helps. my truck did the same thing and the injector was just dirty.

[994X4Blazer]

could be vaccum leak around tbi base. had a firebird with 350 tp inject that made the same nosie it was a cork seal between butterfly and plenum.

[quartermilerun]

IF IT IS A VACUME LEAK TAKE SOME CARB CLEANER AND LIGHTLY SPAY THE VACUME LINE AND AROUND THE OUTTER PART OF THE TB I F IT IS A VACUME LEAK NORMALLY THE CARB CLEANER WILL CAUSE A CHANGE IN IDLE SPEED AND THEN YOU HAVE FOUND YOU VACUME LEAK

[falcon52]

squirrel in motor? haha jj,

IF IT IS A VACUME LEAK TAKE SOME CARB CLEANER AND LIGHTLY SPAY THE VACUME LINE AND AROUND THE OUTTER PART OF THE TB I F IT IS A VACUME LEAK NORMALLY THE CARB CLEANER WILL CAUSE A CHANGE IN IDLE SPEED AND THEN YOU HAVE FOUND YOU VACUME LEAK
^ easy, cheap way to find a problem or at least rule it out:cool::rockwoot:. good luck