1.8 L-Jet AAR No power ? Options

[pete000]

I am experiencing some idle issues with my 74 1.8 L-Jet. The idle is high for about 20 minutes and then comes down to around 800 rpm once the engine is good and hot. Up until then it will idle around 1400 rpms. I assumed there was a vacuum leak so I went through everything and even did a pressurized smoke leak test. No leaks.

Next up was the AAR. I have collected three and bench tested all of them. They all close up in around 3 minutes which seems about right. All work. I tried one afeter the other and same results.

I thought about it for a bit and it seems once the engine is hot enough it closes the AAR from the heat. This lead me to test the voltage to the AAR and yup NO POWER !

Harness looks fine. Any suggestions where to start tracing this? (IMG:style_emoticons/default/idea.gif)

I am currently driving the car with out the AAR and it has idle trouble for about 3 to 5 minutes, after that seems pretty stable.

[timothy_nd28]

(IMG:style_emoticons/default/agree.gif) all good things to check. I also had erratic idle due to the throttle plate not seating correctly because of a weak spring.

You have identified a problem though, the aux air valve has two wires that supply 12vdc only when the engine is running. Did you test for voltage at the aux air valve connector in this condition? If so, we need to know what voltage leg is missing. With the engine running, grab a voltmeter and ground one meter lead probe on the negative battery post. With the other meter lead, probe one of the two aux air valve pins. One of those pins should yield 12vdc. If so, carry on with the next test. Put one meter lead on the positive battery post. Then put the other meter lead on either pin of the aux air valve. You should see 12vdc. Depending which voltage you are missing will tell us which way to trace this fault.