i thought i have heard of this somewhere but in tunercat i cannot seem to find the right table or constant for this setting. anybody know where to look? btw im trying to get rid of my damned split idle blms.

 

anybody?

 

i will look to see . i know my 89 7.4 suburban idles in open loop and goes into closed only when the rpms rise up from idle. mostly at idle the o2s arent hot enough to provide a good reading so the computer is set to go into open loop to provide a stable idle. i will look into the problem and get back to you.

 

Don't know if Tunercat has the same table but in LT1Edit there is a WOT table. This table sets the precentage that you have to depress the pedal before the car thinks it's at WOT or Closed Loop. I would think changing the percentage number above 1000rpm would do what you want to do.

 

i want the car to stay in open loop or freeze at 128/128 while in cell 16 at all times. if a guy can create a program that will lock cell 15 then its conceivable the same thing can be done in cell 16 too... but maybe not.

my only concern is that if my blms are 115/140 then locking them at 128/128 could create a rich condition on the left bank and a lean condition on the right bank. i cannot decide if the pcm is actually making the correct adjustments or if this is a false rich/lean like youd find with an exhaust leak.

 

I am looking into the same thing, except I want 2300rpm & lower to stay in open loop since my 236/242 cam might be too big & causing false readings at the o2's, as soon as my car warms up it surges a lot almost like its stumbling from 1200-2300 under moderate load & light load.

 

Im having the same issue, durring idle with my huge 260 duration cam the car goes into cell 16 and loads the LT and ST fuel trims at max drowning it with fuel. However in open loop mode it runs great. I would liek to be able to use LT1 edit to make my car stay in open loop mode at all times below 3000 RPMS. Right now I am jsut going to put it in open loop mode all the time by setting the temps to 255 C so it never leaves open loop mode. If anyone has answers help us please !!!

 

XTwinTurbo had it - you need to set your TPS% To enable WOT to a 0% for 0-1200 or so RPM (forget what the scaling is). Basically this will put you in PE mode at all times when you are at or below 1200 rpm - so O2 feedback will be ignored, and you can as a bonus do fine grained a/f tuning for this range with the PE vs RPM table (for that RPM Span)

Chris

 

well ill have to do that on a dyno then or find a wideband O2. so i guess there is no way to get it to just stay in open loop??.. that is really what im looking for.

 

yes there is, set your "ENABLE CLOSED LOOP" temperatures to 150 celcious. the car will never get that hot unless its on fire LOL and it will stay in open loop mode. that is how mine is set up now, runs 10 times better.

I tried the TPS voltage trick and my car was in closed loop mode with the WOT tables activated at an idle. However the only thing that does is disable LONG TERM fuel trims. MY car still was doing Short term fuel trims and loading my car with gas at idle causing it to stumble and burn very rich. Altho thats a neat trick, it didnt work for me.

Im heading to the chassis dyno next week to tune mine in open loop mode, however it runs pretty good now

 

i think you misunderstood me. i want the car to go into open loop anywhere below 1000 rpms... thats it.

setting 0% tps and below 1200 rpm for WOT would work but id just need to go to a dyno first so i can record my AFR. this is unless anyboyd knows if i set my PE table values to "0" then wouldnt i basically have the same AFR as if i was in open loop??

would someone be willing to adjust this for me since tunercat doesnt appear to have such a table?

 

I unbderstood what you were saying. I had mine set just like that where anythnig below 1200 RPMS was WOT. Then i set the PE tables to 0 so it would not add anyfuel and it would have the same A/F ratio as it would in open loop mode. However keep in mind, that setting your WOT TPS % to 0 for 1200 rpms and under does not disable the Short Term fuel trims, only the long term fuel trims. It may work for you but it did not work for me. I even set the PE tables below 1200 rpms to -10 and the ST fuel trims compensated by adding 50% more fuel

So back to full time open loop for me, it works great and I can put in some old O2 sensors and run 110 leaded CAM2 race gas.