My Holley makes a high pitch whistle from time to time, especially when idling. Sometimes it stops if I floor the car and sometimes it starts after I floor the car. The sound seems to come from the front of the carb. I just opened it up cleaned everything up installed new gaskets O-rings, pump membranes... but it still whistles. I did however not install the new power-valve I got with the kit, because the old one seemed OK. The carb is a Holley 4165 650cfm spread bore double pumper (yeah I know it's a Chevy carb ) I'm also not getting it to idle properly (to fast). What am I doing wrong here, and where does the whistle come from.
It sounds to me like you have a vacum leak since you can't get it to idle down. Look very close at the base gasket(s). Use propane to find this leak.
I agree, vacuum leak... But, propane never worked for me. I expected it to rev up, but it never did. Actually, I used those little tanks for the camping stoves with a torch head on it...
I agree with the vacuum leaks. I spray carb cleaner around a little at a time. when engine speeds up you'vefound the leak.
Throttle shaft bushings are worn. Buy a new base plate to correct it. There was a seller on ebay a couple years back that sold new ones for around $100. Don't recall their name though. I bought two from them.
Vacuum leaks. If it whistles a tune you like you might save money by not intstalling a high dollar sound system. Dan
never assume a holley power valve is ok. couple of backfires and they are usually toast.unless its a later model blowproof. are the floats set correctly?, to high, it will never idle down. i agree about the vacuum leak, but before i tore it all back off/down,id check a coupla things. is the accelerator pump adjusted properly? are you usin the choke?,or is it just there? are the idle jets adjusted properly?(see float statement) ive actually seen one side to lean and create a whistling sound. im sure you used a new gasket and diagonaly tightened the base. got all your vacuums hooked up/plugged off? all these things make weird things happen. noises too. id opt for a lil(very small amount) of w-d 40 around the base or throttle plate. if it slows down you have a issue. best of luck
Hate to get off topic, sort of...but you said "slows down" when WD-40 is sprayed on it. I have tried a number of chemical sprays to determine if I had a vacuum leak, and none worked...Do I need to look for something that riches my leak out, or leans it out? (ie. bogs it down or revs it up? )
wd-40 will choke it out, as it has a high flash point, and does not burn well. kinda like usin spray on deoderant to find that pesky leak you been chasin,but cant seem to narrow down. just works.
The reason that it disappears when you rev it up is the vacuum is dropping. Listen to these guys. Vacuum leak somewhere.
i would never use propane.. 1 small problem turns into a very bad day haha.. none for me... thanks but wd40 worked for me a long time ago... lucky for me, i havent had a vacuum leak in years
Sounds Like a vacuum leak to me too......SOme newer model Electric sensor carbs, or IAC motor on Fuel injection cars can whistle when when they stick open. Use Carb Cleaner or Brake cleaner with supplied tube to spray around the carb area first. It will idle up when you hit the spot. It won't bog as the Vacuum leak is creating a lean air/fuel mixture. If nothing happens spray the vacuum lines down one at a time. I would also caution you to have a fire extinguisher close at hand. A few weeks back I had GM 3.1L lumina that I suspected had a vacuum leak at one of the intake manifold ports. It also had an Ignition wire that was grounding out in that area(ran fine so I didn't expect any surprises ) and whoof big ball of flame almost burnt my eyebrows off. I put the fire out within seconds but still had to put a set of wires on. The other guys got a laugh at my expense........point is it can happen. The company I work for lost a car(totalled) to a simliar situation. Guy cleaned off some spilled oil on the valve cover on an audi(Customer complained of burning smell). Shut the hood tch walked away and customer followed him inside to speak to the manager. Customer came back outto a ball of fire in less than 5 minutes. Accidents can happen. Be safe
Don't get me started on the morons that use propane as an alternative R12 refrigerent. Less likey to do but was messy back in the 90's
propane as a r12 alternative??? what the (fill in expletive here) am i missing something...or is propane highly volatile and extermely dangerous to have near a combustion engine?
