Is there a way to force Idle only to be open loop?

I am fighting my header glowing problems,It seems headers do not glow untill closed loop is enabled.

Im still fighting it and don't know why,WB reads 14.7 and timing is at 22-25 with a light.


Thanks for any help.

 

As provided I do not believe you can force an open loop idle on $8D. Can you match up the O2 reading during closed loop to what it is right before closed loop?

Is there a difference? If so, then there is a separate idle desired O2 window. May be able to use that.

RBob.

 

I have not found where in the $8D this occurs (and I've tried a few things), but the idle goes open loop after a number of minutes of just idling. I found this out when trying to go through emissions when I lived in an area subject to testing.

There is a timer (though I have not found it yet) where after a certain time it goes open loop. I was trying to find it to make it stay in closed loop longer, but you want the opposite effect.

But there is definitely a timer somewhere there.

A similar thing happens after prolonged deceleration - you can go open loop. Where I live we have some long hills, the longest being a 20 km stretch. Once the ECM goes open loop in deceleration, it takes a few minutes of driving before it will go back into closed loop.

Maybe with those clues, RBob may be able to find the proper timer. But so far, I haven't found it.

 

If I set the closed loop enable temp high it will stay in open loop ,
right?
But it will be open loop in all cells though.
Thanks for the info guys.

If you have any advice about my header glow I would be glad to hear.


I also have another problem. while tring to get rid of the glow ,I set idle timing to 35 degrees. But after checking with a light it still only read 22-25 degrees.
Anybody know why?

 

Yes, setting closed loop enable temperature high will cause it to stay open loop all of the time.

When you set the idle timing you need to do it with the closed throttle SA table. It is also desirable to change the main SA table to match so that a transition from closed throttle to open throttle is smooth.

RBob.

 

Wow,thanks alot.
I never seen the connection there. I love when I learn something new that helps me.
Thanks again for all the help you guys.

 

How about idling in PE mode?

Regards,
Gary Anderson

 

I was just looking at anht and the timer Glenn was talking about appears to be at $8529. It disables blm updating after a specified time. Maybe if you set this close to zero, it would stop idle from ever learning, effectively making it open loop.

Regards,
Eric

 

Let me ask a non-tuning related question....sorta.

Did you degree your cam? If not the actual timing (distr) might be correct, but the cam could be starting to open the exhaust valve before the combustion is complete, hence the fuel is burning in the pipes. Advancing the timing enough could help the problem, but you will probably introduce others.

If you did not degree your cam, my thoughts are its in wrong or was ground wrong. Two very common mistakes that people don't realize.

Also if your glowing just a tube or two, those lobes could be off. In order to make sure a cam is 100% on, you really need to degree each cylinder/lobe, but most just do #1 and assume the rest are on. Not always the case, but 1 is better than none.

Another reasons you should degree the cam is 1. The timing set you get could have the keyway off, and you will be off by that amount. 2. The keyway on your crank could have been misplaced.

Or all of the above could be off a tad to make you WAY out.

My advice at a minimum, if you didn't degree the cam would be to pull the timing cover off and check it to make sure your not off a tooth, and while your in there, although its gonna be a beotch to do while in the car, degree that cam.

OK. Sorry to throw that out there, but you have been tuning long enough that I don't think the problem is tuning/timing related in the sense of the ECM tuning.

By holding open loop you are really just masking an underlying problem that may be responsible for your slower than expected ETs.

Hope this helps.

 

Yeah Ski,
I did degree the cam. Also all tubes are glowing.
Yesterday I put the stock 22lb inj. back in just to try.
Thought maybe a longer pulse at idle might help.
Seemed about the same,which has been better lately that im running more timing . 28 at idle.

The only time I see it now is when in dark garage it is showing some slight glowing.
Maybe im looking to far into this,can someone else here try the same to see if their car does it in a dark garage?

Man if I had a Hand help pyro,that would make this alot easier.
Gonna see if I can pick one up from work maybe.

Thanks for suggestions and help.
Please keep em coming.