So, I have been having what I thought was the problem of a stuck-open AAR.

1. Start car cold
2. Car idles at 1800 RPM during warm-up
3. Car gets warmed up and now starts idling at 3,000 RPM
4. Pull input to AAR and you can feel it is still sucking air in (a ton).
5. Plug the input to AAR and idle drops to 950 RPM.

Today, I replaced the AAR (thanks fellow 914world member) with another one. However, the problem/symptom persists just as above.

So now I suspect I am not getting power to the AAR so that its little bimetallic strip can be heated up. Where does the power wire for the AAR trace back to in the car (74 2.0L)? How can I test that wire?

White wire, engine harness, switched power. Power is constant with key in on/run position. Terminal 12 on relay board.

Traces to Terminal 13 on 14 pin main harness connector on relay board. Terminal 13 is Black w/ Red Trace and also used for fuel pump power.

With key on, you should have 12 VDC at the AAR connector.

Well, given that the fuel pump works, I suspect yet another bad AAR then?

The AAR I sent you was tested.
I am positive it is working.
Testing is simple.

I applied 12 Volts and the it fully closes in about 5 minutes.

I won't get time to work on it until this weekend. Where did you apply the 12 volts? It didn't have a spade connector on it and the sheath was not trimmed back on the wire.

I am currently having this same problem. Hopefully once my AAR valve is fixed (or replaced if can't be fixed), my car will run properly. Also idling at 3000 rpm. When the car gets hot, it struggles to start, if at all due to AAR making the car run lean.

The wire goes to positive 12 colt and you have use another wire to ground if from the metal shell. you can attach it to the holes for the screws.

I would start by checking timing on yours.

Hard to start, not a bad AAR symptom.

So you trimmed the wire at some point to connect to the 12 volt source? Or it had a spade connector on it? I'm not doubting you. Just trying to figure out how you hooked it up to 12 volt without any exposed wire.

I got it like that. you can easily ad a spade connector.

Yes, I did add a spade connector for the install. Easy peasy.

Still scratching my head on how you hooked it up to 12V power with no spade connector or removing any sheathing.

Initially I thought it was the timing and had the timing adjusted. It was checked again last week and timing is fine. The not starting part was because the AAR was causing a vacuum leak, causing he engine to run very lean, which in turn made it difficult to start the car after it got hot.

On a 2.0L, the ground is through the mounting screws. All that is needed is to provide switched 12 VDC to the wire.

Since neither of you live where it gets really cold, I plug them off (I live in SoCal). A ball bearing in the hose works just fine. It may stumble a bit from a cold start, but once you get a bit of heat in the engine, it will run just fine.

The AAR does not affect the mixture. On L-jet systems, the air that it lets into the manifold is metered air--it has already been measured by the air flow meter. On D-jet systems, the MPS detects the extra air coming in and adds fuel to compensate. The mixture stays correct.

In fact, most vacuum leaks on a D-jet system simply result in a higher idle, not in a mixture change.


You have not found the cause for your hard starting; keep looking.

--DD

Certainly yes these would be used, but did you remove the sheathing (ie strip the wire) on the wire coming from the AAR or did the sheathing magically conduct electricity to the alligator clips?

The text I highlited in red is a totally wrong assumption.
Read what Dave Darling wrote.

I've read half a dozen threads lately that are blaming the aar on the car not running or running poorly. Its not you guys problem. Its only there to enhance warm up. It will not cause the car to run rich or lean. Like Ron said, they're not even needed in a semi warm climate.

from sitting on your computer, that is an assumption.
Try testing YOUR wiring harness to make sure you actually have power for the AAR...

It is powered by the same pin on the relay board, but there are two different wires going to two different places.

Rich

Well, I was able to get my AAR working properly today. First, I was not getting 12V to the AAR. Looking at the relay box in the engine, I took out all the relays and one of the m (fuel injection power one) had the "blue-ish" powder-like/gooey-like substance all over it like you see on a battery cable. Cleaned that out as good as I could today but still no luck.

But then...I remember that I had recently put in a VDO oil temp gauge and had stolen the ground wire from the clock in the center console. My clock had been working sporadically after I had jerry-rigged a quick ground wire (well, what I thought was ground "enough"). I ended up daisy chaining the original ground that went to the clock with the VDO oil temp gauge and presto!!

Thanks for all your help.