Need MORE help with TunerPro

[jim_in_dorris]

Sorry Six, I was under the impression that in open loop it used the commanded AFR only while idling.

[rsicard]

Sorry Six, I was under the impression that in open loop it used the commanded AFR only while idling.

What is this about???

[rsicard]

Regardless of the ECM being in closed or open loop, the VE table is ALWAYS used for fueling. Closed loop simply trims or adds fuel from the VE table (and other multipliers) in the final injector PW calculation.

Thanks for the clarification. First, the narrow band Oxy sensor is disconnected. Second, the resistance of the knock sensor was 90Kohms+. Went to the auto parts store and spent another 50 bucks for a new sensor that measured 3.8Kohms which is what it should be. With the engine slightly cooled, removed the bad Knock Sensor and installed the new sensor. Reconnected the IAC motor, left the Oxy sensor disconnected, and ran the engine without the Laptop and TunerPro. The CEL comes on steady and likely in LHM mode. The battery and switched 12 volt input to the PCM are wired together. May need to run the battery input directly to the battery. This may have an effect on the CEL sequence.

Have not gotten to enabling emulation nor getting out of LHM. Still learning with each engine run. Need to go back to the original unmodified binary file. Also need a test point on the Knock Sensor wire and Oxy sensor wire to check with a multi-meter. Many variables to get sorted out. Have a lot more questions than answers for them.

[rsicard]

Regardless of the ECM being in closed or open loop, the VE table is ALWAYS used for fueling. Closed loop simply trims or adds fuel from the VE table (and other multipliers) in the final injector PW calculation.

This statement sure makes good sense. The microprocessor needs at have the tables to process all the input variables in the proper manner to provide the appropriate outputs.

[rsicard]

Attached are test 1,2,3,4 xdl files of engine runs. test4 seems to be the best. At idle, PBW is 2.x+. Modified Mask from 0D to AA as suggested. This last run was uninterrupted by DA and TunerPro not quitting. Hooray. Some success. Now let the engine cool down some. OK when electric fan sucking air through the radiator. Once everything is shut down, engine temp soars to 200+ degrees F. Mechanical bourdon tube temp gauge is LH cylinder head. Still need to know what to do about the ignition timing. This last run, test4, at 2000+ RPM, ign timing as indicated on TunerPro gauge, fluctuates back and forth and is reflected in RPM indication also.

[rsicard]

Regardless of the ECM being in closed or open loop, the VE table is ALWAYS used for fueling. Closed loop simply trims or adds fuel from the VE table (and other multipliers) in the final injector PW calculation.

Attached are test 1,2,3,4 xdl files of engine runs. test4 seems to be the best. At idle, PBW is 2.x+. Modified Mask from 0D to AA as suggested. This last run was uninterrupted by DA and TunerPro not quitting. Hooray. Some success. Now let the engine cool down some. OK when electric fan sucking air through the radiator. Once everything is shut down, engine temp soars to 200+ degrees F. Mechanical bourdon tube temp gauge is LH cylinder head. Still need to know what to do about the ignition timing. This last run, test4, at 2000+ RPM, ign timing as indicated on TunerPro gauge, fluctuates back and forth and is reflected in RPM indication also.

[rsicard]

In LHM, the EEPROM or Emulator could be completely disconnected from the ECM and run exactly the same. LHM runs off the redundant fuel device, the small IC in the '7747, and not the EEPROM.

If you are indeed in LHM, then no matter what you do with the bin, and emulation, you will never see a change.

Did you enable emulation by clicking on the blue EEPROM button? If so, did you disable checksum by changing the mask ID byte to AA? If the checksum is not disabled, then an ECM can revert to LHM even after being started if anything is changed in the bin.
A way around the checksum issue is to upload the entire bin when you make a change without enabling emulation.

To check for LHM, turn the ignition on and if the CEL (Check Engine Light) just comes on solid without a flash, then you are in LHM, if the CEL flickers quickly (and usually dimly) then you are in LHM. The CEL needs to flash, then stay on solid when the key is turned on to know that you are running off the EEPROM or emulator.

Forgot to mention, turning the power on to both switched +12vdc and battery +12vdc inputs, the CEL flashes one distinct flash and then goes steady on until the engine is started. Need to replay the recorded file now.

[rsicard]

Regardless of the ECM being in closed or open loop, the VE table is ALWAYS used for fueling. Closed loop simply trims or adds fuel from the VE table (and other multipliers) in the final injector PW calculation.

Analysis of the test2 recording shows the timing and associated RPM excursion with the TPS remaining the same. Any suggestions regarding this? See attached.

[sturgillbd]

With you powering the constant and switched power at the same time will make it harder to start. I learned this lesson while testing my harness before actually routing it in the body. If you power both up at the same time, the IAC doesnt reset and go to the park position properly. As for the fluctuations in rpm etc, the pcm is trying to learn. If you warm it up and datalog, you can load the data in the spreadsheet and get the VE table closer. The ideal situation would be for the pcm to not have to make any correction for fuel. Real world is that it does... especially with weather changes but getting the ve table closer to ideal will help. I would set it up with a battery disconnect switch and an ignition switch on the test stand. My engine would surge with a constant throttle position until I got the VE table dialed in closer to what the engine was happy with. A test stand is not good for tuning. You have no real load on the engine, You can tune a few ve cells in the closed throttle table and not much more. You can also play with the idle spark to get the smoothest idle if your cam is other than stock. Actual tuning can only happen with varying the load and rpm.

[rsicard]

With you powering the constant and switched power at the same time will make it harder to start. I learned this lesson while testing my harness before actually routing it in the body. If you power both up at the same time, the IAC doesnt reset and go to the park position properly. As for the fluctuations in rpm etc, the pcm is trying to learn. If you warm it up and datalog, you can load the data in the spreadsheet and get the VE table closer. The ideal situation would be for the pcm to not have to make any correction for fuel. Real world is that it does... especially with weather changes but getting the ve table closer to ideal will help. I would set it up with a battery disconnect switch and an ignition switch on the test stand. My engine would surge with a constant throttle position until I got the VE table dialed in closer to what the engine was happy with. A test stand is not good for tuning. You have no real load on the engine, You can tune a few ve cells in the closed throttle table and not much more. You can also play with the idle spark to get the smoothest idle if your cam is other than stock. Actual tuning can only happen with varying the load and rpm.

Thanks ever so much for the comments. Just wanted to get the idle ignition timing proper and VE fuel to 14.7 to 16 AFR. Ideally, the leaner the better at idle so it will pass emissions without any difficulty. Its what comes out of the tailpipe that matters on emissions tests. Should be able to tune the idle to 16:1 AFR and still be running at a moderate RPM by tuning the ignition timing. Right now ignition timing on the TunerPro screen and what is actually seen with a timing light are two different things. Which should be done first, the ignition or the VE tables? I would guess the ignition, yet don't know how to fix the disparity between TunerPro PCM timing advance display and the actual timing light reading on the engine balancer. Does something need to be disabled to modify the PCM timing tables at idle to get a correlation between PCM timing advance display and actual timing light readings? PLEASE ADVISE. Still learning this tuning thing.

I will wire the battery hot input to the PCM separately to the battery to see if that fixes the IAC failure issue seen on the last engine run. This change should fix the power up sequencing for the PCM, especially IAC to park properly.

[delcowizzid]

the iac is bottomed out trying to lower idle the car thinks its in drive as the park neutral switch mustnt be earthed commanding 500ish rpm idle in gear.when you did have the O2 plugged in it was real rich and pulling all the fuel out that it could

[rsicard]

the iac is bottomed out trying to lower idle the car thinks its in drive as the park neutral switch mustnt be earthed commanding 500ish rpm idle in gear.when you did have the O2 plugged in it was real rich and pulling all the fuel out that it could

Trying to understand these statements in depth. Since there is no position feedback from the IAC, the binary file must throw in extra pulses to the IAC to make certain it is closed. Not yet certain whether the IAC motor itself is at fault or power up sequencing is not proper. Not certain that there is a single wire input to the PCM for the park neutral switch. Will have to investigate this. As far as the O2 sensor is concerned, right now it is disconnected so that the PCM cannot go closed loop.

[Six_Shooter]

You NEED to have the battery wire connected to the battery. There are certain things that happen AFTER the ignition is shut off that pertains to the IAC and other functions to ensure proper start up up the next time. Fix this first and foremost.

I'm not sure why you want to disable closed loop right now, but you can disable it in the bin by setting the closed loop enable temp to max.

There is a single wire input for the neutral safety switch that needs to see a ground to know that it is either in park or drive. IIRC when grounded the ECM thinks it's in park.

[delcowizzid]

And if your commanded timing doesn't match actual we have to get back to basics before any tuning.
First you are going to want to follow the factory procedure and set base timing with either the est bypass wire disconnect or diagnostic port jumpered(I don't know the process for this ecu but the USA guys will) also make sure the spark reference setting in the bin matches weather it be 0 or 10 degrees or whatever the bin expects.
Then I would follow the factory base idle speed adjustment which normally involves forcing the ecu to fully close the iacand unplugging it and once again unplugging the est bypass/entering diagnostic mode and setting idle rpm to its base value with no iac or spark compensation modifying rpm.
Then plug the o2 back in and fire it back upland get a log while confirming commanded timing in the datastream matches actual crank degrees
Once the house keeping is finished and squared away tuning will be easier

[Fast355]

Thanks ever so much for the comments. Just wanted to get the idle ignition timing proper and VE fuel to 14.7 to 16 AFR. Ideally, the leaner the better at idle so it will pass emissions without any difficulty. Its what comes out of the tailpipe that matters on emissions tests. Should be able to tune the idle to 16:1 AFR and still be running at a moderate RPM by tuning the ignition timing. Right now ignition timing on the TunerPro screen and what is actually seen with a timing light are two different things. Which should be done first, the ignition or the VE tables? I would guess the ignition, yet don't know how to fix the disparity between TunerPro PCM timing advance display and the actual timing light reading on the engine balancer. Does something need to be disabled to modify the PCM timing tables at idle to get a correlation between PCM timing advance display and actual timing light readings? PLEASE ADVISE. Still learning this tuning thing.

I will wire the battery hot input to the PCM separately to the battery to see if that fixes the IAC failure issue seen on the last engine run. This change should fix the power up sequencing for the PCM, especially IAC to park properly.

It would help alot if you posted your .BIN file and the actual initial timing value you are running with the EST connector disconnected. Also post the datalog definition file you are running. It may be a problem between the .XDF you are using and the .ADX file.

For example if you have the initial timing set at 10* BTDC, have the .BIN file set at 0* your crank timing will read 10* higher with the timing light than the Tunerpro Datalog. If you have both the initial timing set at 10*, you .bin set at 10* and your .ADX has no compensation it would also read off. Post what you are using and maybe I can help shine some light on it.

Also just FYI, running lean will likely hurt your emissions. Your best bet is to keep it in the 14.2-14.7 range and pull about 6-8* of timing out of the test area. When you run it lean your mixture will not fully combust despite raised combustion temperatures and you will have a spike of unburned Hydrocarbons (HC) and Nitrogen Oxides.

Back when my old 83 G20 van still had the original quadrajet fed 305 in it, I used to block off the vacuum advance with a BB prior to the yearly smog test. It would easily pass with the timing retarded and almost always failed with the timing at factory spec.