EFI relay unplugged

[rcb280z]

Blue, I will have to wait for it to cool down around here again. It has warmed up here so I know the cold start probably won't work anyway. Maybe I will be able to run the test tonight. Will keep you posted.

[240260280z]

No worries....btw I just diagnosed a bad AAR on a friend's car today.

[rcb280z]

I can't wait to check this one. I hope in a way it is not bad because it's fairly new... 2 years old. But then again if it is bad this could fix the problem. What were the symptoms on your friends faulty AAR?

[240260280z]

Well the AAR is just a "leak around the throttle valve to increase rpms when the engine is cold".

In my friend's case, his idle was very high. When I pinched off the hose with my fingers during a test drive, the rpm's dropped immediately.

In your case, the AAR may be working, or it could be stuck closed or it may be simply sticking.

[rcb280z]

So if the AAR is opening to much on an engine that is possibly on the lean side to begin with and it is not that cold outside for the cold start to work, but the AAR is open, then it could be considered a vacuum leak correct? And would cause an engine to idle poorly until it started to warm up like my Z. It is supposed to cool down tonight so I think I will push the Z out of the garage and let it sit outside for a few hours and then perform those tests. Will keep you posted.

[240260280z]

Sort of,

The AAR does not cause a lean condition because it is down steam from the AFM. So any air that it flows around the throttle valve through the AAR would have been drawn through the AFM and correspondingly more fuel added by the AFM detecting this.

The AAR is basically just to keep the rpm's up on a cold winter morning so that your car can idle faster and not chug chug chug and die. On cars without AAR devices, you would have to sit in the car with foot on the gas and nurse it along until the engine came up to temp. Now with the AAR you can start the car then get out and scrape the windows without having to worry about it dying .

[black gold man]

Is your car auto trans.

[rcb280z]

No it's a five speed. I wont be running the tests tonight. I thought about it and want to run these tests when I can take my time and not be rushed. That may not happen until this weekend unless something happens before then. I will keep you posted. Thanks Blue.

[rcb280z]

UPDATE

Ran the AAR test and here is the result. Pulled hoses and the AAR was open ( about 1/4). Put hoses back on and started the car. Pinched the supply hose and it stalled right away. Restarted and allowed it to warm up (10 min). Pinched same hose and nothing happened. Steady idle. Pulled hose's and AAR was closed. I'm ready for the next test.

[240260280z]

Perfect. AAR is ok. Let me think about it.

BTW: What are your RPM's when it starts cold and after it warms up?

[rcb280z]

Start cold....about 950-1000 rpms with unstable idle. After I raise the throttle (I shouldn't have to) for about 15-20 seconds and let go, I get a stable idle around 1300 rpms until the engine starts to warm up and then the throttle slowly drops to about 850. Takes about 5 minutes.

[rcb280z]

I also pulled the AFM to throttle body boot to look inside the throttle body. It is still clean and is adjusted correctly as per FSM. Butterfly is closed completely with engine off.