Red Comet Racer

I recently had motor rebuilt and have been driving smooth for about 650 miles. The only problem is that the car idles at 1500 rpm. My question is, does the idler pulley have an impact on idle speed. This is a simple (and maybe easy answer) question but I ask because my a/c & idler pulley is not attached.

HAILERS

No. It has no effect at all.

Your problem *sounds* like the water thermowax not functioning right and keeping the throttle plates open a touch. Check out your water thermowax by the FSM and or do a Search on this forum for Water Thermowax.

Red Comet Racer

thank you for the reply, i have checked the usual, throttle sensor, idle screw, vaccume lines, and so on.

HAILERS

When the engine is fully hot, the items #2 and #3 are seperated. Seen this with your own two eyes?

On a non turbo it's hard to see because the throttle body is upside down compared to a Turbo throttle body. IF the cam #2 does not seperate from the roll pin #3, then the throttle plates stay cracked open a touch.

Red Comet Racer

Thanks, I found out that the thermowax rod is not extending when at normal engine temp. Would replacing this lower the idle? Also does the idle cam have to touch the roller? It says in the manual that there is a gap between these two, I am not sure since isnt the roller supposed to rub against the cam with the two tick marks.

HAILERS

The cam rides on the roller til the piston fully extends. When it fully extends, the cam seperates from the roller.

You know that screw with the spring that rides on the bottom of the piston??? I think if you fully turn it clockwise til it can't be turned anymore, the cam will come off the roller. I'd count how many time I turned that screw as you do that.

That's not the way the thing is adjusted, but the cam will come off the roller and the throttle plates SHOULD close all the way if you do that. Do that and see if the idle drops.

Make sure the water hoses are attached to the throttle body that heat up the water thermowax. That could be the problem.

That is one primary reason the engine has to be HOT when adjusting the TPS. The TPS adjustment has to be done with the throttle plates fully closed. If the cam/roller are still in contact, then the plates will not be fully closed.

For me to do my 86na water thermowax adjustment, I had to remove the throttle body. It was a lot easier than working below the car looking up and fishing around. I've done it both ways. Removing the throttle body was a lot easier. Talking a NON TURBO.

Red Comet Racer

ok then if i adjust the screw as you said, then is this a temporary fix or can i leave it that way? Dont I need the water thermal wax for when it warms up?

HAILERS

Yeah, you could leave it like that.