A Thank You and a Question!
 

I was a complete auto-newbie when I first bought my FD, and especially so with the FD itself, but I do have to admit feeling a certain amount of pride in how much I have unexpectedly accomplished on my own thus far. Before my FD, a simple change of spark plugs was the most I had ever done on my own. Now, thanks to the invaluable knowledge imparted upon me through regular perusal of these forums, I have managed to change the air filter, O2 sensor (first time splicing a wire and everything!), replace the rubber intercooler hoses and stock elbow with the Greddy hard pipes, install the PFC, and put on a new exhaust. As meager a feat as that may seem to some of you, it is huge for me, and I thank all of you that made it possible. I am no longer afraid of my car, and I know I can do nearly anything with the right information and tools.

Having said that, I have what I believe to be a pretty simple question. I want to at least make some attempt at fixing the issue myself, and I could use a nudge in the right direction. Also, I did try searching for the answer I am looking for, but the very nature of the problem makes it difficult to encompass in a search. I'm sure some of you must know what I mean.

Anyhow, my question is, what system(s) on the car kick in about 60-90 seconds after the car is started that could possibly cause the engine to run "rough" in the 1k-1.5k RPM range only? It seems like a pretty trivial problem really, and I only ever notice it while I am waiting for the engine to warm up. I swear, I have started the car at times where the engine was just the right temperature to have the idle start at 1.3k-1.5k RPM, and for the first minute or so, it idles in that range perfectly fine. Then, something soon activates that raises the RPM by 100-200 when it happens, and from that point on, the engine is rough when between 1k-1.5k. Once the engine is fully warmed, the only way to really reproduce it is by carefully revving it and letting off within the 1k-1.5k range. I can feel it get all stumbly-feeling as the RPMs come down, and I get small pops from the exhaust at times.

It seems harmless really, but if I learned anything from all of you, it is to be too careful rather than not enough. Anyone have any basic suggestions as far as a starting point goes?

Thanks!

- Jim

I was a newbie just like you a long time ago. Glad to see you are coming along well.

As for your idle question, thats still beyond me. I had idle problems with the stock ecu but fixed them with my PFC by tweaking the maps. Mine started rough, then was steady when warm. Every now and then it would be rough even with good temps on the engine. Who knows...still voodoo to me.

Good luck and someone post on this so I know for the future.

its normal, just sounds like the car is warming up, when i first start my car, the idle is a touch rough but after a small acceleration and a few secs it runs fine. With that said, the engine idle will react to headlights or Aircon.

The stumbling and revving are not normal. The soft pops are normal.

I suggest you adjust your TPS per the instructions in the FAQ. This takes care of many issues, and you should at least verify it's correct before going much further. You have a PFC which makes the task a little easier.

Have you had your PFC tuned yet?

Dave

Did you follow the "idle learning" process as specified in the PFC manual?

If so, follow Dgeesman's instructions and verify the TPS sensor ranges. Easy to do with the PFC on the Sensor screen.

It is also a good idea to check the mechanical settings on the throttle body. If the mechanical settings are off, that can throw off the TPS settings. Do that after you figure out if your current TPS settings are out of range.

No, the PFC has not been tuned yet. Yes, I did follow the idle learning instructions exactly as specified in the PFC instructions.

I will try adjusting the TPS and see how it goes.

Thank you all!

- Jim