I posted earlier about idle problems. Since then I had some wiring issues that I cleaned up. The idle has been improved, yet not where it should be. When I first start the car, it seems like it is idling fine. After driving it for awhile, the idle gets progressively worse. It seems like the idle gets richer as it goes into closed loop. It's hard to tell though, b/c when I first start the car in the morning it runs rich b/c it is cold. When it warms up and goes into closed loop it starts to surge. I see this most as I pull up to a stop light. The RPM's will surge so low that the car sometimes stalls. I believe that the target A:F ratio is 14.2 or 14.3 at idle. When tuning the car from the beginning, I watched the numbers on the VE chart and made adjustments there. I watched the boxes that the idle was jumping around to and basically set all of those numbers close to the same amount. I figured this might help with the surging idle. I'm not sure if that is what you are supposed to do, but it seemed to work. When the surging idle gets really bad the car gets really bogged down. When I give it gas, it sputters and pops. Unfortunately I didn't have the computer hooked up at the time to watch what was going on. It was obviously running very rich. I don't get it though b/c I have the A:f ratio set low and the VE values are set somewhat low. Why is the car running so rich and why does it surge? I have to pull over and rev the car to clean the gas out of the pipes. I'm really confussed on what else I can do to fix this problem. If someone is familiar with this system and has an idea please let me know. Thanks
PS I just checked the Global Cal file and the Target A:F is 14.2 and VE numbers range from .240 to .250 in the boxes where the idle jumps around in.

 

Check your Warmup Enrichment graph, it allows you to adjust VE vs. Engine Coolant Temperature. You should adjust this table in tandem with your VE so that the warmup enrichment table has a value of around 1.0 at a warm engine, and greater than 1.0 as needed to provide the necessary fuel to run a colder engine.

Also, have you set up your IAC correctly, so that it hangs around 5-7 counts at a warm idle? You may have to adjust your throttle blades to make that happen if you haven't already done so.

 

I have it between 5-9 right now. It seems to jump around a bit, but for the most part says in that general area. From what you said before, the numbers in my VE should be 1.0? Isn't that really rich?

 

Tune your VEs as needed, I doubt they will be around 1.0 at idle.

DON"T use your VE table to add/subtract fuel due to the engine being cold or warm. Tune the VEs on a warm engine and use the warmup enrichment table to correct fueling vs. temperature.

 

Ok cool. Do you have any idea what could be causing the surging idle?

 

that post from about is me. I was signed in under my roommate's cp.

 

You did the right thing by making the VE numbers similar in your idle area, just make sure they are correct so that you are actually seeing your targeted A:F number(s). Check your timing map to make sure that the idle is not wandering through differing values as that can also contribute to the rolling/surging.