openecu.org

Anyone know the specific functions of the Open Loop Load #1 and Open Loop Load #2 maps?

Open Loop Load #1 obviously takes the ECU out of closed loop at certain load and rpm levels. However, it isn't clear what Open Loop Load #2 does...

Thanks.

Make, model, year of car?

Freon wrote:Make, model, year of car?

Mitsubishi, Eclipse GTS, 2003. Same ECU as an EVO.

I am pretty sure they function like this.

Open loop 1 is the threshhold of of peddal pressure where the after catalist O2 sensor feedback is not used and AFR is determined by the pre-catalist O2 sensor. This allows more power by the ECU not using an after emission AFR to determine "catalized" involved correction.

Open Loop 2 will turn off the AC compressor (if ingaged), stop all EGR functioning and will not be seeking any form of a "lean condition" because of O2 sensor feedback/corrections. Only the mapping of the High Octane AFR map (hoping there is no knock) will be used. The ECU is not using the pre-catalist O2 sensor for the most part, where the final injector pulse-width is computated using the ECU data, MAF readings, and other engine feedback alone. I am unsure if the ECU referances O2 feedback or correction at this point, but should not be making corrections outside of about 1 AFR of what is on the mapping.

Someone correct me if I am wrong.

mtcavity wrote:I am pretty sure they function like this.

Open loop 1 is the threshhold of of peddal pressure where the after catalist O2 sensor feedback is not used and AFR is determined by the pre-catalist O2 sensor. This allows more power by the ECU not using an after emission AFR to determine "catalized" involved correction.

Open Loop 2 will turn off the AC compressor (if ingaged), stop all EGR functioning and will not be seeking any form of a "lean condition" because of O2 sensor feedback/corrections. Only the mapping of the High Octane AFR map (hoping there is no knock) will be used. The ECU is not using the pre-catalist O2 sensor for the most part, where the final injector pulse-width is computated using the ECU data, MAF readings, and other engine feedback alone. I am unsure if the ECU referances O2 feedback or correction at this point, but should not be making corrections outside of about 1 AFR of what is on the mapping.

Someone correct me if I am wrong.

Thanks for the contribution. However, Open Loop #1 disables all the O2s and the car goes into Open Loop operation and references both hi oct and hi ignition maps (essentially doing what you say Open Loop 2 does). I have logged this event. I've leaned out my idle to nearly 16.0:1 and it is a good way to spark plugs clean. I've also leaned out my cruise a bit, too.

Open Loop #2 must use a different algorithm for added protection...

You are absolutly correct, I am in the dark on the EVO ecu. My Mitsubishi Galant is in the same boat, but does not have knock function on the stock 4G64. I have one ignition map and 2 AFR maps, and am sure the ECU to be more emissions friendly than the EVO and did not figure High Octane maps would be sought. Thank you for the re-education, I prefer to be wrong and learn than just wrong.

That was me pissing in the wind with that explaination, just a little got on me that time !

Which one sets the limit for egr operation, 1 or 2?

Trying to see if I can run lean of stoich (in open loop), yet keeping the normal egr operation parameters intact.

Reason why is because egr conserves fuel, and in addition to leaning at cruise, with a small amount of spark advance, will save even more gas. If I can keep combustion from going silly

That is why I started this thread: to get the answers like the one you asked. Unfortunately, I think very few of us will alter those maps. I'm not sure which map, if either, controls the egr solenoid.

I have headers so my egr pipe is disconnected. I did lean out my idle (16.5:1) and cruise (~15.5:1). Be careful with the timing advance.

would you mind posting your maps?

1&2 are both set the same on mine. load and tps.

guess I'd like to see what most clearly defeats closed loop.

brucer wrote:would you mind posting your maps?

1&2 are both set the same on mine. load and tps.

guess I'd like to see what most clearly defeats closed loop.

Open Loop #1 definitely defeats Closed Loop. I know this because I have a data logger that shows Open/Closed operation. Set all your Open Loop #1 fields all to 10% and your car is in Open Loop all the time. You can also change the Min Coolant Temp for Closed Loop to a temp that the car will never reach like 250 C* and you car won't go into Closed Loop

using the coolant temp to bug out of closed loop results in a cel.

My load open loop maps are set very low, (both)\ as are my throttle open loop maps.
I do get very momentary movements in the wideband back towards 14 from the 15~16 that I cruise in. Not sure where that comes from.

whats the cel code,,

p0125

insufficient coolant temp for closed loop control,,since you set the min temp for closed loop higher.

I've seen about four different settings for open loop, I tried another that didn't work, or I didn't wait log enough for it to become active(?). Anyway I ended up zeroing out all the maps, tps open and load open. So far it seems to be OK.

(?) I downloaded to the ecu a map and it didn't seem to make a difference but in a matter of a few minutes it seemed to switch. Was that just a faulty observation?


evo 8, 2003.