Okay, got the car back now...

[smitty_64]

All,

I had all the tuning and horsepower questions, but now I have the car back. Still doesn't seem to have the horsepower I should expect from a Stroker and the idle sticks at 1500 after pressing the clutch for about 10 seconds before it idles down to 1000. When I turn off the ignition, there is a hissing sound, kind of like a pressure relief valve (yes, I know there isn't such a thing in cars). The sound comes from down around the intake gasket or valve cover. My guess is this is a vacuum leak that is not only manifesting itself in the idle hanging but also stealing my horsepower. The tune is right now. Am I right, or is it normal to hear that sound with my combo?

Greg

 

[1TallMF]

I hear this hissing sound on my car on occasion after shut down. I figure its one of the pistons stopping at the top of the compression stroke, and air is slowly decompressing at the valves and/or piston rings. Could be air coming back out the intake from this. I'm not sure though

 

[The Green GT]

I hear a hissing on my stock 302.

 

[94gts]

i heard a HUGE hissing from a mercury sable that i had to move at work today when i shut it off. i never have been able to figure out what that noise is

 

[smitty_64]

Well, I don't know that I am that worried about either of these problems since I scared a Cobra today, but one thing I am noticing is that the idle will fall to 1000 as soon as the car comes to a complete stop. May still be the shift retard that others have mentioned. As far as the hissing, the builder wants the car back in Monday to change and check the oil and put it back on the dyno again now that most of the problems have been straightened out. I'll let him listen to it.

 

[stprorolla49]

the hissing is something in the air intake...it happens to me to, and its more evident with a cai...