whistWhistle at idle, stalls out at speed help needed

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Aug 15, 2005
Lemoore, CA (south of Fresno) / Cortes Island, B.C
Whistle at idle, stalls out at speed help needed

8/ 1973 fj40 with the F engine

I have a little problem. I have plenty of power at idle and can rev really high in neutral, but going down the freeway at about 2600 RPMS, the rig starts to stall out. I have to pump the gas and it lugs for a minute then picks back up and drives fine for a hundred yards then starts all over. I hear a whistle coming form the carb (I believe that is where it is from) I might have gotten a hold of some bad gas and it might have clogged my filter. But I am thinking it is time to drain out the tank, replace the filter, and do a carb rebuild with eh whistle. Anyone have any better suggestions of what the problem might be? Before I tear into the carb, any suggestions about why I would have plenty of power in neutral, but on the freeway it stalls out higher RPMS.
Last edited:
sounds like the clogged filter prob that I had.

thanks. I was going to try that first
BTDT; Mine's done that many times. I have a cheapo inline fuel filter that I replace about once a year. That's the first place to look.

Do the easy stuff first and recheck it. If it happens again check the sight glass if its empty or below than it should be. Start thinking about doinh the following: cleaning out your gas tank, blowing the gas line, or replacing the fuel pump could be going out on you. Mine was doing something similar but was not whistling it ended up being a flakie fuel pump.
Last edited:
chech your choke my f with asian carb was doing this type of thing my choke was stuck...runns good now

spray a little carb cleaner around the outside of the carb and base and along the rest of the intake manifold at idle and you should hear or feel a difference in running where an intake problem exists. also chaging to a clear fuel filter will allow you to visually inspect. Rust in my tank requires me to change mine pretty regular. let us know how you resolved your problem! eh?

( Oh! yeah! try not to do the cleaner trick on an already hot engine as it can provide an awfully flamable atmosphere!)
FJ40Jim said:
Two different symptoms, 2 different problems.

the whistle is a vacuum leak, usually the manifold gasket.

The soggy throttle response sounds like it's running out of fuel, as others suggested.

I am pretty sure the leak is at the manifold as you suggested. Easy enough fix.

Pulled the fuel filter last night and it was black inside. Not good. I will pull the tank this weekend and flush it out. Should only take a few hours. I'll put in a new filter (probably use a clear cheapy so I can watch the color of the gas for a while until I know it is running clean) then switch it out with an OEM unit. and liberally spray carb cleaner in the carb to flush that.

Thanks for all the help everyone. If this doesn't work, I think I have a rebuild date with the carb.


Users who are viewing this thread

Top Bottom