Return to Closed Loop?

[DPS]

Hey guys,

I'm just wrapping up a tune on a '97 Z28 with the EFI Connections COP and 0411 swap. The car is running pretty good. The MAF in the car was descreened so I decided to run SD.

I attempted to put it into CLSD when I was finished but it continues to stay in OL. This creates a couple of questions:

1. What's the risk associated with leaving it in OLSD? (FYI...it doesn't have a WBO2)

2. What could I be doing wrong that is keeping the car in OL?


The car is currently a dedicated road course car. The owner did express some interest however in putting it back on the street.

Any thoughts are welcome.

-Brad

[mr.prick]

Are there any DTCs?
Post the .tun

[WeathermanShawn]

What could I be doing wrong that is keeping the car in OL? The owner did express some interest however in putting it back on the street.-Brad

Brad, open-loop is going to need a really good VE Table. Biggest problem on the street (open-loop) is heat soak. You go to Home Depot..turn off your car..IAT may now be 160F around the IAT sensor. Without a custom OS..chances are your car starts very lean (if it will start).

CLSD or a custom OS allows trimming to stoich. Not a bad deal. Whether for road course racing one is superior to the other..perhaps others can comment.

Good luck..

[DPS]

DTCs:

P0102
P0103
P0463


I followed SSpdDmon's notes on setting up OLSD found here:
http://forum.efilive.com/showthread....577#post105577

I imagine that the problem resides in the processing enablers since I wanted to fail the MAF without tripping an emissions code which would result in a failed inspection if he were to put the car on the road.

Go easy on the .tun fellas. I know that the VE is "peaky" and I'm very sensitive

There is definately some smoothing to be done.

Many thanks,
Brad

[WeathermanShawn]

I attempted to put it into CLSD when I was finished but it continues to stay in OL. 2. What could I be doing wrong that is keeping the car in OL?Brad

Brad, if you wanting to go CLSD you just need to change B3801 to Enable (if you want LTFTS) and change B4205 back to stock values..I.E. 34C..(Seems to be a mislabel on the EFILive Labels..IAT?).

That should put you back into CLSD. If you are getting DTC's for the MAF..then you should be SD..

Is that what you wanted to do..go back to CLSD?

[DPS]

Thanks Shawn.

I had initialy intended to put it into CLSD. Once I started to struggle with it I contemplated OLSD.

Either way, it looks like the car will get more of my attention before I consider it done.

On a side note. I hate opti-spark ignitions. This car has 29,000 miles on it. It arrived with a bad upper RPM misfire with a new opti installed. Opti #3 was installed and still had the same problem. We had an o-scope hooked to everything you could imagine. After many nights of scratching our heads, the car received the 0411 and LS COP conversion. Results are attached.

-Brad

PS - I hate opti-sparks

[WeathermanShawn]

Wow, thats a pretty big improvement. Congratulations..that is impressive.

I think I understand on the tune. You are keeping it OLSD. A few others are more expert on the MAF DTC's. I know the Processing Enablers get tricky..the 'Non-Emissions' one always got me confused. But if you are getting a DTC code on the MAF..you should be all SD.

If you ever want a sanity check..you can always change the Low-Octane by .5 -1 degree. If the MAF is failed, you will be running off the Low-Octane.

So it looks like you are utilizing PE Mode as your Commanded AFR vs B3605. Probably not a bad way to do a road course car.

Good luck..and good work..

[5.7ute]

One thing to note Brad is you will have to do some serious work on that VE table over 4000 RPM. Even though you rarely hit these areas you should hand fill them somewhere in the ballpark. Hint: Edit the table in 2d view to see the trends clearer.

[DPS]

It's on my "to do list."

Thank you!

[joecar]

...

I imagine that the problem resides in the processing enablers since I wanted to fail the MAF without tripping an emissions code which would result in a failed inspection if he were to put the car on the road.

...

Brad,

To run SD the PCM must see a failed MAF dtc... i.e. the MAF dtc's must not be set to Not-Reported or Non-Emissions... set them to 1-Trip.


I don't think anyone has yet found a way of running SD without failing the MAF (i.e. triggering a MAF dtc).