Having this rhythm surge while part throttle under 5% tps it feels like someone is pulling the e brake on and off managed to capture it on the DL I also noticed that when in park and holding the rpm steady at any rpm below 2000 it would surge about 100 rpm reducing the PRP - Gain vs O2 Error helped the surge almost eliminated it while in P/N. Talked to RBob about it he suggested its not enough proportional gains and to adjust the four PRP tables I've been tinkering with all four tables for a few hours now but haven't really made any progress

here is a DL that best shows the problem tps is steady while rpm dips 100rpm everytime the o2 mV value drops

currently running these PRP settings and also re ran a ve learn holding in the 1000-1500 rpm but the learn didnt change much of anything i also recall that the problem was not present while in VE learn



will throw in the stock ecu and aujp in the mean time to see if my problem is mechanical b/c i just changed the o2 to a NOS AC delco three wire but i have noticed this ever since switching to the ebl

 

Is the heated O2 due to it being further down stream of the exhaust ports? To help with this also work with the INT update delays. Since the issue is only a low throttle use the gms/sec airflow value from the data log to know which areas of the tables to change.

Slow down the INT update rate via:

INT - Delay vs Airflow

Then adjust the proportional gain and duration via the airflow tables of each:

PRP - Gain Multiplier vs Airflow
PRP - Duration Offset vs Airflow

RBob.

 

heated o2 is installed on the shorty header collector it is a nos acdelco AFS-74 ran two different settings today seen in pics below PRP - Duration vs O2 Error was return to original 3005 value one was with low airflow values and the other high both had the same lowered value int delay vs airflow both settings didnt not improve or worsen condition still has a noticeable buck while under 5 tps in any gear coasting still feels like e brake is being pulled surge can be seen while in P/N also





threw the AUJP in there same day drove around for quite some time and there was no surge in P/N holding a 1k-1.5k or any noticeable buck e brake being pulled feeling while under the same conditions with a low throttle input

with aujp in P/N need to get cable to DL the stock ecm

 

That is what I was telling him last week as well when I looked at the datalog that he sent me, the INT was moving extremely fast and my immediate thought was he adjusted the rate beforehand...

- Rob

 

slow it down to what? the pics above show that i slowed it down already should i keep going lower and also lower the INT - Delay Mult vs O2 Error?

here current vs 3005 bin

 

I didn't say to slow it down, I said that that was my immediate thought when I seen the INT moving as fast as it is moving. I cannot see the changes that were made in the bin that may be effecting the INT because you only uploaded datalogs, but the BLM is very stagnant in the datalogs meanwhile the INT is all over the place, Understand that the BLM is initially set to move with the INT whenever the INT is 4 counts away from 128, yet during the datalog your INT (during surge) can be seen up to 145 at times while the BLM does not move, or simply does not move fast enough, nor even have a chance to catch up to it. Once the INT exceeds 132 the BLM should move in conjunction with it, yet the BLM stays rich at 110-112. You might want to increase the BLM's update rate just to see if this at least eliminates the surging so it at least has a chance to work in tandem with it...

- Rob

 

Here is bin im working with as for increasing BLM - Update Rate im assuming you mean making it faster which would mean taking it from the current 450 msec and decreasing it to say 300? I tweaked the prp and int settings mentioned here to what i could get to have the least amount of surge in this bin, it will be a little while before i can test though

 

Try restoring the first five values using the original 3005 values in the area below;

INT - Delay Mult vs 02 Error

The first four rows were reduced by almost 50% in your bin...

- Rob

 

If the INT is all over the place, I believe RBob would say that is the INT chasing O2 cross counts.That would suggest need for more prop gain relieving the INT of doing that job.

 

"Talked to RBob about it he suggested its not enough proportional gains and to adjust the four PRP tables I've been tinkering with all four tables for a few hours now but haven't really made any progress"

increasing the values PRP - Gain vs O2 Error made the issue worse particularly in P/N couldnt not get any noticeable difference tinkering with all four PRP settings will try streetleathals suggestions along with more tinkering the PRP settings when i get a chance

 

Ever resolved? I'm experiencing similar surge issues.