I just put a motor in my car from the Salvage yard. It runs great. Thing is that it runs really fast (idle). I have adjust the screw on the throtle body (92 VX hatch D15Z1) and got it to run much slower. BUT when I press the clutch it runs at 2,000 to 3,000 rpm for much longer than I'd like it to, then it will eventually slow down. I'm going to go drive it some more. ANY HELP, IDEAS?

 

I just got back from a food run and wal-mart stop. The engine speed is really fast. It likes to be at 2500. I notice that when I start the motor, it idles just under 1000 but if I'm driving and I go to nutral, it idles high (2500 or so) and doesn't come down.

 

anyone?

 

have you checked for vaccum leaks?

 

I have the same problem. I don't know what it is.

 

sometimes there could be a catch or snag in the adjustable throttle body screw. make sure you clean up the throttle body, intake, etc... with some seafoam and then see how it runs

 

adjust your throttle idler screw. i had the same problem with my 94 ex motor. its a flat head screw.

 

I have adjusted the screw to the point that it is all the way in and that helped with the initial idle speed. When I stand over the engine and turn the throtle, the engine goes faster and then doesn't like to slow down. I'll take the air intake off and see what I can see. Do I need to remove the throtle body to clean it? What is involved in cleaning it?

 

Sounds like a vacuum leak. The idle screw won't rev your car to 3000 RPMs normally. If you bury the idle screw and it still does it, you definitely have a vacuum leak.

Check hoses and also make sure they're all going to the right places. Spray a fuel source like carb cleaner all around the throttle body gaskets and intake manifold flange and see if it affects the idle speed (adding a fuel source to the vacuum leak). Avoid painted surfaces with that stuff. If it does affect the idle, you need to fix whatever is leaking.

Also, your engine is from a VX, what's your ECU and the rest of the chassis? Is that all VX stuff, too?

 

Yes, Every thing is as original. All VX. I will try to find a leak, and I will try to clean the throtle just for kicks. I still have the old motor so I could take some junk off of it if I need.