Help!..RX-7 Fast Idle Cam Siezed

I finally figured out why my '88 RX-7 base model idles at ~1750 rpm. When I pulled off the upper intake manfiold & throttle body assembly I found that the fast idle cam assembly was siezed...and I think I know why. The water thermo valve that permits the vacuum operation of the #2 secondary plates no longer functions. Also whatever the actuator is that sits below the water thermo valve is...well it dosen't appear to work either because the spring loaded plunger that is supposed to push on the fast idle cam and disengage it from the main throttle shaft cam assembly is siezed. So I think that the fast idle cam just siezed in place over time because the water thermo valve and the actuator/plunger siezed. Now what do I do???

After cleaning the fast idle cam/spring/shaft assembly with CRC TB cleaner and 4 days of spraying the fast idle cam assembly with PB Blaster I can now "rotate" the fast idle cam by hitting it with a mallet via a screw driver. I can not rotate the fast idle cam with my fingers alone and the return spring will not overcome the friction. At this point I think I may have three options. I need some input on them.

1) Do I understand the way the fast idle cam is supposed to work correctly? I think it is only engaged when the coolant temp is less than 140 degrees F. If this is true maybe I can just tap the cam to where it is disengaged with my precision "mallet and screwdriver" and leave it like that permenently. One thing that has me confused is that there is a "finger" that is apparently attached to the fast idle cam / shaft assembly. When I tap the fast idle cam with the mallet and screwdriver the "finger" does not move with it. And although the roller on the main throttle cam is no longer in contact with the fast idle cam it does not seem to close the primary throttle plate any further because the main throttle cam is hitting the "finger". Is the "finger" supposed to move with the fast idle cam? If so, I guess I could wail on it with a mallet or bend it out of the way so that the main throttle cam bottoms out against the screw stop on the other side. Would this work? In addtion I would cap the vacuum port for the thermo wax valve on the upper intake manifold and the vacuum port on the diaphragm actuator for the #2 secondary butterflies.

My thought is that both the fast idle cam and the #2 secondaries are only in play when the engine is cold. So I would just manually speed up the idle by giving the car a little throttle until it warmed up. Once warm the engine should operate as intended and idle correctly and PASS EMISSIONS...I need the car to pass. Am I on the right track here?

2) Somehow completely free-up the fast idle cam assembly. Any ideas? And then I would have to see if I could buy a new water thermo valve and the fast idle cam actuator somewhwere. By the way, does anyone know what the actuator for the fast idle cam that pushes on the plunger is actually called?

3) Try to find a used throttle body somewhere. I have had no luck so far. I am scared to know what a re-manufactured one what cost...but I can not even find such a thing (no luck at Mazdatrix, Rockauto and NAPA).

Sorry for the long post. Your technical wizardry and advice is greatly appreciated.

-Ray

I'm having a similar issue with my FC, though I think in my case it's a vacuum leak:

http://grassrootsmotorsports.com/forum/grm/idle-oscillation-at-1700-1900rpm/12134/page1/

There's a link to a (very large) rx7club thread on this issue, as well as to a treasure trove of FC info called Global Vicinity. I wish I could be of more help, but I'm as stumped as you are and the kid who was supposed to help me remove the throttle body and UIM this Saturday flaked out on me. Hell, I'm having trouble getting a hold of anyone who can help me.

In reply to RexSeven:

I just posted some tips from my UIM removal in your idle thread.

www.car-part.com for all your replacement throttlebody needs!

In reply to Armitage:

Thanks! That site is awesome. I checked the site...saw the price range and then decided to call Mazdatrizx even though they did not have a TB on their website. They sold me a used one for $50 (matching the low price on the site you sent) from one of their core engine exchanges, and gave me some technical tips on cleaning the water thermo valve. My fingers are crossed.

I'm gonna phone Mazdatrix and ask them to sell me a cam for a rotary. "But you sold one to racer_ace!" How long can I maintain the misunderstanding?

DON'T DO IT AT WORK! at least not at work with everyone standing around watching and snickering, you'll loose it for sure if someone in the background is snickering like crazy. Otherwise, how long can you play dumb?

racer_ace wrote: ...and gave me some technical tips on cleaning the water thermo valve.

What, pray-tell, were those tips? I might as well clean the thermo valve when I have the TB/UIM apart.

In reply to Keith:

Fantastic idea!

I almost titled my original post "HELP" RX-7 Cam Siezed" by I wussed out. I figured I would get more help being serious

In reply to RexSeven:

Apparently the themo valve gets plugged with crud. The secret trick is to use a paper clip or toothpick to clean it out. Run hot water (above 140 F) through yours first and do the blow through check before going through the trouble of rmoving yours and cleaning it out.

Spinout007 wrote: Otherwise, how long can you play dumb?

For years, it would seem.