my 89 lwb did the same thing and I couldn't get it to work right so I just bought some nozzle jets and put those one, they each have three little jets so there's 6 streams of fluid being sprayed, works great.
http://rides.webshots.com/photo/2271842990049304464tNBTwe
that's the only pic I have that shows them, you can see the two black things on the hood.

1989 Montero 4dr V6 3.0l