duno1818

i just changed my pulsation damper. i broke some vac lines changeing it. so i ended up replacing all the vac lines. shes runnin good now except she idleing at 2000 rpm. before i changed the pulsation dampershe was idleing at about 800-850rpm. i can get it to come down to about 1000rpm but i have to be in gear and brake while driving to get it to come down. as soon as i give it any gas shes back up to 2000rpm again. any clues as to what might be causing this? Thanks in advance.

AGreen

iTrader: (11)

clog in coolant passage for thermowax? vacuum leak?

duno1818

I changed all the vac lines so it can't be that how could i check to see if coolant passage for the thermo wax is clogged?

satch

iTrader: (1)

When you believe the car is fully warmed up find the piston which protrudes outwardly from the Thermowax unit and you will see an upside down screw where the point of the screw presses against the piston. Now press down on the screw/linkage and if the idle rpm drops then the piston is not extending enough which could be caused by the coolant hose to the Thermowax being clogged.

RotaryRocket88

iTrader: (7)

I'd suspect a problem with the throttle linkage. Check for throttle cable for any binding/excessive tension. You could try disconnecting the throttle cable, then see how it idles. If it changes, you know where the problem is.

duno1818

i pushed on the yellowish piston looking thing and nothing happened. the throttle cable is actually alittle loose so its not pulling the linkage before i give it some gas. i did push the opposite way on the linkage and the idle dropped alittle. could the linkage itself be stuck or out of adjustment

satch

iTrader: (1)

The Thermowax piston is made out of metal so not sure of what yellowish thing you're referring to.

satch

iTrader: (1)

..

satch

iTrader: (1)

Check post #86 in the following link and press down as pictured. It might be easier to use a screwdriver to reach the necessary linkage to help in pushing down the linkage. Also disconnect the electrical plug to the BAC as your attempted adjustment by chance might perhaps be causing more air into the throttle body and thus a higher idle. Disconnect this plug first and go from there.

https://www.rx7club.com/showthread.p...dle+cam&page=4

RotaryRocket88

iTrader: (7)

I'm thinking the "yellowish piston looking thing" may be the thermovalve. It has 2 vaccum ports, a vent on the end, and it's threaded into the thermowax body.

satch

iTrader: (1)

I understand that but not what was pushed on for there is no exterior part of the Thermovalve that is moveable in any manner.

RotaryRocket88

iTrader: (7)

I guess you could push on the filter. Clearly not what you meant.

duno1818

so the yellow **** with the two vac lines that come off of it is part of the thermo wax? what i pushed on doesnt move what so ever. i'm not sure were im looking exactly and the picture from post #86 is hard to tell what part of the engine bay is in.

satch

iTrader: (1)

The Thermo valve is part of the Thermowax so the linkage w/the upside down screw is located below the piston which is located below the Thermo valve. You definitely don't want to push down on the plastic Thermovalve unless you're intent on breaking it. The linkage I speak of is fairly obstructed from view due to an item which can be unscrewed/removed to access the linkage containing the upside down screw.

RotaryRocket88

iTrader: (7)

Here, I found a picture showing the thermowax piston, the adjustment screw, and the cam that presses against the throttle linkage. When extended (like shown), idle will be high. When the coolant warms up, the piston will retract, the cam will rotate, and idle speed will drop.

http://media.photobucket.com/image/r...012_172104.jpg

duno1818

ok so i found the piston with the upside down screw. i can push the srew/linkage down(seperated from piston) and nothing changes. i've tried to push the piston up but it doesn't move. also theres no change when tryin to move the piston. does this mean its not working? do i need to replace this? or are the hoses clogged which would maybe not allow that piston to move at all?

duno1818

i wanted to add that my rad. cap at the thermostat is leaking. i already ordered another one but was wondering if this might have anything to do with the problem.

satch

iTrader: (1)

The piston should extend as the car warms up but it takes a decent amount of time to occur so check the position of the piston before startup and after the car has been idling for twenty minutes or so check the position of the piston to see if it has moved any.

duno1818

when i first found it the car wasn't running and as it was running/warming up i keep messing with it trying to push up and pull down on it. it never moved. i let it run for at least 40 min before finally cutting it off. does it mean the the hoses are clogged or what?

satch

iTrader: (1)

It would appear that way but if the car were idling and the screw/linkage were pressed downwards then the idle should drop. Even if the coolant hose to the Thermowax was clear doesn't necessarily mean the unit will work properly as they can malfunction when properly fed hot coolant. When the car has been running for a while you can place your hand on the hose to check if it is hot or not as perhaps the hose is cool when it should be hot which would lead one to think the water pump/thermostat could be responsible. In this case the coolant hose to the Thermowax should slowly heat up as the car is running.

HAILERS2

About the screw that sits on top of the thermowaxs piston...........IF you screw the screw clockwise the throttle plates will close sooner as the water temp rises in the manifold.

If one screws it completely clockwise............the throttle plates will be fully close all the time and sort of defeat the purpose of the thermowax design............but if you do screw it all the way in and the next time the engine fully heats up and NOW the idle is much lower, that proves the water thermowax either was rigged off a bit or the thermowax isn't extending as much as it should when hot. That make sense?

As the water gets hot............the piston extends outward pushing on the screw which in turn makes what they call the fast idle cam come off the roll pin and in turn that makes the plates go fully closed. Yeah

Easier to work on on a Turbo car than a non turbo (throttle body flipped 180* so the thermowax is on the top instead of the bottom). I never could really get to that screw on my non turbo very easy. It was easier for me to just unbolt the throttle body/cable and work on it off the car. Personal preference thing.

I've had the throttle body off the car and poured boiling water over the exterior of the thermowax to see if it would extend. They always do/did......proving more or less the thing is functional.

duno1818

well the hoses were hot so i'm gonna try to pour boiling hot water on it like hailers said to see if the piston moves. i'm gonna try that tomorrow. also the idle did't drop when i pushed that screw/linkage down(away from the piston). what might that mean?

HAILERS2

idle did't drop when i pushed that screw/linkage down(away from the piston). what might that mean?
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Means to me the thermowax isn't the item that is causing the high idle. Sorry 'bout that.

Maybe you reconnected the vacuum lines you broke on the engine to the wrong places? Or forgot to repair a broke vacuum line. Where are those vac lines you broke located?

Did you accidently cross up the two of the three smaller vac lines located on the front of the throttle body???? There's three vac lines. One above the other. Is it possible you crossed up the two smaller ones?????? That might make a difference in idle. I KNOW it will in fact. But I remember it as more of a crummy idle than a just high idle.

On a stk non turbo there is a black item called a Spider located under the dynamic chamber. It has four small vac lines and one large one. The large one goes to the larger of the three nipples on the front of the throttle body. The smaller four go to the oil injectors top nipple. Now inbetween the two oil injectors on the intake manifold sits a nipple. This nipple takes a small vac line and that line goes to one of the two small nipples on the front of the throttle body.

The other of the two small nipples on the front of the throttle body goes to feed some of the solenoids on the left side of the engine. IF you cross these two small vac lines on the front of the throtttle body, then the idle will be effected. Unforturnatley I don't remember which of the two go to which spot. It makes a difference though. I can look tomorrow if its needed.

satch

iTrader: (1)

Since your idle was fine before removing the UIM/throttle body it would make sense, as HAILERS suggested, that there was a mix up reconnecting the vacuum lines. But getting back to the linkage below the Thermowax, the linkage will not budge if it is lightly pressed down as there is much force needing to be exerted to press it downward. Are you certain it is moving downward? Pressing down on the linkage in front of the throttle body is very easy to do as there is little effort required but the linkage on the back is a different animal.

Also, the round shaped component that prevents one from getting a good view of the rear linkage is the Dashpot, which if screwed in incorrectly might cause the primary throttle plate from closing properly. You can remove the black plastic intake tube connected to the throttle body off and check the single primary throttle plate and see if it appears to be very very close to being closed as it should "or" if there is a sizeable gap. The larger the gap the more air enters the Dynamic Chamber thus causing a higher idle speed.

duno1818

the first set of throttle plates are wide open(just two at top) the second set are almost completly closed(three plates, two on top one on bottom). i also tried switching the vac hoses and nothing change except when i actually took them off. also i did push the screw/linkage down with a srew driver as far as i could push it and there isn't any change. the only time the idle changes is if ipush the opposite way on the throttle. the rpms drop but then go back to about 2000rpm. right now its sitting at 2300 rpm but that seems to flucuate