Ok everyone

Here is one for you, and no it has nothing to do with F1. Ha ha. My 73 1.7 fuel inject is idling high. around 1800 rpms. When I purchased the car about two years ago it idled around 500-800 rpms. then one day without notice it changed.

I changed all the vac house as many on this site suggested, no change. But here is the thing after the car has been running, say about 45 minutes the idles comes down and everything is fine.

Does this has something to do with the fact that the engine is now running at a much higher (its regular operating) temp? That seems to me the only thing that would be different from when I start it up cold.

Any thoughts?

PS and check the sandbox for my latest posts. ;-)

At a guess, the AAR is no longer plugged in, or the electrical part of it has failed. Does it close after ~5 minutes with the engine on?

--DD

I just went through this with my 1.7 also. The AAR would be the first thing to check. Remove it from the car, and using a DC bench power supply, give 12 VDC to the wire and attach ground to the body of the AAR. If it heats up but doesn't completely close in a few minutes, it'll need an overnight soak in WD40 to free it up.

If the AAR is good, there's lots of seals to check: injector seals, manifold gaskets, throttle body gasket, cold start valve gasket, etc

You might also want to check your deceleration valve. Tightening down the adjustment screw on mine trimmed a few rpms off my idle, and got rid of some occasional backfiring issues I was having.

No, it definitely take over 30-40 minutes to come down...

LOL what the hell is a AAR? Im very good mechanically speaking but don't know my way around the nine one four like most of you. just tell me what it is and what it looks like and I will figure it out.

-jp-

AAR is to the right of the yellow arrow in picture. AAR stands for auxiliary air regulator. In a perfect world the 914 idle should go down with in five minutes.

The idle may take that long to come down--but is there air going through the AAR during that time?

Pull the hose from the AAR to the air cleaner off the air cleaner. See if air gets sucked in. It should when the engine is cold, and there should be none after the engine has been running about five minutes.

--DD