pinkrx7

iTrader: (2)

Im trying to unplug the coolant line from the rear plate (on the block) to the coolant line on the throttle body.

The nipple is currently plugged with black RTV what can I do?

catch-22

iTrader: (2)

wow......i would try to get a small very sharp pick and get between the metal and the rtv and pull up on it being careful cause you dont want it to fall down in there. then if you get it out you can punch the guy who did it in the face. why do want the TB coolant anyway? doesnt get that cold in cali.

pinkrx7

iTrader: (2)

i feel like cars idle funny cold in morning starts with the fast idle off

catch-22

iTrader: (2)

rotaries do that anyway they dont like the cold. TB coolant isnt gonna do nothing for you unless your sucking in neg degree air.

mono4lamar

iTrader: (32)

Slit up it with a razor blade and peel it all away. If it's really good RVT it's not going to come off without a good fight. Goodluck...

catch-22

iTrader: (2)

haha i thought the coolant was inside the hole. wow thats a 2am post for ya.

arghx

iTrader: (3)

Do you think these cars stall/idle rough in the cold from the factory? The fast idle cam is there for a reason: to open the butterflies during a cold start. That type of system has been around since carburetors. The coolant supply is what rotates the cam down so the idle will drop to whatever you have it set to:

93 Service Highlights document page F-19



There is no reason to remove the fast idle cam unless you simply cannot handle installing that one inconvenient cooling hose. I know it's annoying, but Mazda put it there for a reason, although it is now unnecessary on the drive-by-wire system of the Rx-8's.

joff

iTrader: (1)

Although for some unknown reason Mazda chose to continue to route coolant through the throttle body anyway on the RX8.

pinkrx7

iTrader: (2)

No I like the fast idle cam, but are you our new workshop manual sage? You seem to know that thing inside and out !

its inside the nipple/pipe going into the block.. I think I will try to drill it then find a way to pull it out..

arghx

iTrader: (3)

The reason why I know the FSM's and service highlights documents so well is because I had to self-tune Power FC's on both 2nd and 3rd gen cars, and getting the idle stable requires detailed knowledge of how the emissions systems work. In the process, you get an appreciation for many of Mazda's designs--or at least an understanding of why they did what they did given the technology they had and all the emissions and driveability constraints.

I suspect it is for more consistent operation of the drive-by-wire motor (stable temperature), although the people who remove it don't seem to notice any effects. I say that because in similar fashion the 2nd gen ISC valve has a coolant hose going through it but removing that hose does not have a big effect on its operation. Here is Mazda's explanation for that design ('86 service training manual page 4-53):



if they don't have coolant hoses going through those old ISC valves (or the Rx-8 TB), there is at least a minor chance of premature failure or inconsistent operation. That could be due to an unstable temperature of the ISC/TB electronics for long periods of time. How premature of a failure would occur? who knows? There's also a chance that, without a coolant hose, somebody in some odd climate will have a driveability problem due to a stuck ISC/TB butterfly valve. In either case, from Mazda's perspective the coolant hose would be insurance against a TSB or warranty work.

I just wish Mazda had thought about those climate concerns when they designed the original OMP calibrations of the Rx-8, which did not inject enough oil for desert climates, thus leading to premature engine failures.