93civEJ1

iTrader: (7)

Just wondering the above question. I know a full out standalone like the AEM will, but are their any ohter choices of managment like UTEC of XEDE that will control idle/closed loop fuel operations???

rebelzx

iTrader: (4)

Closed Loop is full throttle right? Most piggybacks and reflashes control closed loop. I thought that open loop was partial throttle. If you meant open-loop tuning, the new firmware for the UTEC is supposed to be able to do it.

MalibuJack

iTrader: (5)

Closed loop fueling is the typical part throttle fueling that the ECU performs.. open loop fueling is when you use a lookup table (maps).. The UTEC's (upcoming) open loop fueling supercedes the ECU and directly controls the injectors. But this isn't what you were asking.

I haven't seen any ECU that will do completely closed loop fueling at WOT except some of the more exotic setups..

I don't know about the AEM's part throttle cruise or if its capable of feedback (closed loop) fueling.

YOu need to be more clear what exactly is it that your looking for..

Closed loop fueling on the factory ECU uses a target fuel ratio of 14.7:1 when driving at low throttle and cruising or idling.. Obviously the only adjustable parameters is the timing, the fuel trims (so the ECU doesn't hunt as much) and the target AFR.. All piggybacks will let the factory ECU do its job because it does it fairly well. The only time you'd have trouble is with very large fuel injectors or cold start (cold start is also open loop and can be controlled with a piggyback) Obviously for the ultimate control a full standalone is going to give you that, but I'm not sure how each of them handles part-throttle cruise, or whether they even utilize closed loop fuel control for it. (I assume that the AEM does)

Oh well, a little rambling, but I hope I got some of the info out there..

93civEJ1

iTrader: (7)

what it is I am looking for would be the idle closed loop operation. The ECU tends to hunt very much for the stoich mixture with cams. Adjusting the cam gears helped for a little while, but now it seems to have came back. I would also be looking for something that would be able to help or move up/take away fuel cut besides a reflash of the ECU.

93civEJ1

iTrader: (7)

Thoughts on the UTEC and XEDE??

MalibuJack

iTrader: (5)

In closed loop anything will hunt a bit.. Usually it happens due to climate change or change in engines output (air density, load, a/c, etc..) and it will hunt until it relearns. Without adjusting trims it'll happen every time the ECU is reset.

On cold start, you can use the 0% Column in the UTEC to adjust your fueling at idle, but upgraded injectors are a bigger contributor of hunting than cams.. Cams affect airflow and the "pulses" in the airflow can cause the MAF sensor to read up and down causing the idle to surge up and down, or just be choppy (lopey).. Plus with the bigger injectors, that same 1% injector duty you see at idle is dumping a little more fuel, since its the minimum, it will generally swing between rich and lean (and hunt for the mixture and never hit it) reducing cam overlap will smooth out the idle which will in turn give the MAF stable airflow readings so it won't hunt as much, but you also will need to raise your idle speed so the airflow is a little higher and the minimum injector duty will be enough to keep the ECU happy..

I think anything capable of closed loop operation may have this problem since the issue may be fueling related and unless you can allow it to run a little rich and be happy, it'll always hunt.

MalibuJack

iTrader: (5)

BTW, with an adjustable (blowthrough) Maf you can solve this issue because the output Karmann frequency is more stable, plus you have some adjustment so you can raise or lower the reading slightly on the unit alone. You can also do this with a calibrated MAF translator and a GM Hot-Wire sensor (3")..

vividracing3

read the cam timing test & tune sticky if your having problems w/hunting @ idle it sounds like a valve timing issue. The stock ECU should have very little problem maintaining a pretty smooth idle (almost no hunting) with those cam gears