I have a 94 accord with the 4 cyl.non vtech engine. It sounds like I have a vacuum leak between the intake and the fire wall. I felt all the vacuum lines I could see to see if moving them changed the sound but found nothing. The engine seems to be running normal. Its pretty loud so seems like it would be effecting something.

 

Did you do ye old, Carb/MAF cleaner spray trick around the manifold to see if the problem went away?

Try unhooking the booster vacuum line, plugging it, and see if the sound goes away.

Automatic? Locate the vacuum hose feeding the rear mount, IIRC that circuit normally has an air bleed and if open it will not affect idle but may cause some noise if the diaphragm is blown.

 

Yes,it is an automatic. Will try these tomorrow. You know something weird is my brakes seem to have gotten better. I seem to have more pedal than before. Not sore if that has anything to do with the hissing though.

 

If by more you mean stiffer, then it is your booster leaking vacuum and you have less assist making the pedal firmer.

 

Its not a vacuum leak if only the intake hose is leaking.

 

Brake booster hose for sure. Pedal is a lot stiffer.