yeoldepirate

I'm not sure what's going on. Here's the deal..... My thermostat went bad, so I took it out for about two weeks while I waited for the Mazda dealer to get my new one in. After I replaced it, my car started acting real funny. At cold start, I rev up to about 1800 rpm, and it seems like something just starts cutting out. It won't go past 2000. Sometimes it stalls, and when it does, if I leave the key on, I can hear a hissing and clicking sound under the upper intake. It only does it if it stalls WITH THE KEY ON, AND LEFT ON. If I turn the key off, no sound. I've come to the conclusion that it's still pumping fuel, cause if I leave the key on for a little while, it floods. I don't see any fuel leaking from the pulsation damper, so I'm lost on what it might be. Any help would be appreciated. By the way, my car is an 88 se with basic mods.

go_speed_go

The clicking sound is probably the BAC valve. It's valve is constantly moving back and forth when the key is in the ON position.

cirkitbrd

ok, i'm not a expert, but your really gonna hate me after this post ..... ok, check your fuel system...., pulsation damper, pressure regulator, fuel lines....,, but i have had this hissing sound on my car, but mine did not run at all., my problem was either injectors or the orings on the injectors, i'll know in a week

yeoldepirate

bump

user 84205

Hey dog,
I got an 97' FD in mint condition and all tricked out. I have the hissing and clicking all the time but I do have a GTR fuel pump. Did you only the thermostat? Sounds like something is not connected back to where its suppose to be. Fuel sounds fine too me though, but when you rev it to 2000, does it pop? or just cut off?

70boss302

Sounds like an air leak to me and the high rpm is from a lean condition. I would spray WD-40 around the hissing noise and see if it affects idle speed. If it does, then you need to fix the leak. Lean conditions can ruin your motor, so don't wait too long. Bill

yeoldepirate

Thanks for the input so far. I tried spraying carb cleaner around the intake with it running. No change. So I guess it's not a negative leak. I just hope it's not a positive one. Any other ideas?

yeoldepirate

BUMP