13B BANSHEE HOWL

[bldn10]

Side seals went a month ago; both rears were in pieces. I got the engine rebuilt and have it back in and have just gotten it to start. It seems like it will run OK at higher RPM but, of course, I don't want to run it there yet. It is extremely rough below 3000-3500 and will not idle. On the other hand, at about that level and above there is a scream from what sounds like under the intake. It comes on and goes off like a light switch at the magic level and lags behind a bit as the RPMs drop. I've never heard this sound before. Any ideas?

[Speed Raycer]

My first thought would be a vac. leak at the intake manifold

[xr4racer]

Make sure you have the injector seals in especially the seal that is under the injector.

[bldn10]

I'm looking for a vacuum leak but haven't found anything. I have new washers on the injectors but wouldn't I get some gas leakage if they were not sealing?

BTW I mis-spoke- it was not the side seals it was the green rubber oil seals.

[bldn10]

AND WE HAVE A WINNER?

xr4racer was correct - the washers (Mazda calls them isolators) I got from the place that cleaned the injectors were too big - they literally would slide off the injector. I got some genuine Mazda ones and it purrs like a kitten. They did not leak gas because there is a vacuum there - the sound was the air being sucked in and the washers acting like reeds.