No knock, ECU pulls timing - why?
Originally Posted by dubbleugly01
I second the idea of a cam position sensor issue, intermittent problem.
tapping into the MAF signal (vs running something inline like a ECU+ AFC) to run diagnostics doesn't work. I tried it last week and it made my car run with extremely rich with retarded timing. somehow the signal gets distorted by tapping into it.
Originally Posted by Nad1370
Another way to rule out Coolant temp sensors is to jump the connector with a 300 ohm resistor.
This will give the ecu 185*F reading from the CTsensor.
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This will give the ecu 185*F reading from the CTsensor.
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Just a suggestion that every once in a while turns out to be the cause of some very screwy drivability issues is to check your grounds, and I assume you are pulling obdII data stream that the ecu is actualy seeing for suspected sensors/parameters as opposed to a spliced in datalogging system because the readings can be different to the ecu due to poor conections at splices, terminals and ground points
I kill myself sometimes by bypassing the simplest of things in my diags at work
Originally Posted by EFIxMR
tapping into the MAF signal (vs running something inline like a ECU+ AFC) to run diagnostics doesn't work. I tried it last week and it made my car run with extremely rich with retarded timing. somehow the signal gets distorted by tapping into it.
For example - SAFC and Emanage can run a maf signal right through them with no distortion (Assuming they are running properly)
Originally Posted by DynoFlash
It depends on what you are tapping into it with
For example - SAFC and Emanage can run a maf signal right through them with no distortion (Assuming they are running properly)
For example - SAFC and Emanage can run a maf signal right through them with no distortion (Assuming they are running properly)
Originally Posted by DynoFlash
That is very possible indeed - however it would usually trigger a CEL if that were the case
I personally have an Evo (pre-Evo 9) Diagnostic harness I created that lets me tap into most of the signals, its important that you do it with an oscilliscope with an isolated input so you don't affect the signal any more than necessary.. HOWEVER for the MAF signal, the harness I created has an S-AFC installed on it so I can plug it in and quickly view it..
Anyway, back on topic.. Until we know what the MAF frequency and other sensor data actually is in his logs for that area, its difficult to go any further..
Anyway, back on topic.. Until we know what the MAF frequency and other sensor data actually is in his logs for that area, its difficult to go any further..
For those of you who don't know how severe this can get here is a screen shot of my ECU+ log of a drag run last night. My timing should run no less than 8 degrees as per my EcuFlash rom that I tuned, but somehow when I got into 4th gear I felt the loss of power and upon review, bingo! -2 degrees timing!
I think somehow ECU is picking up the konck. I experienced the same thing when I gave too much timing for my car ( or use SAFC to lower the maf signal to decrease load value). with my lean tune, I can't push more than 5 degree of timing in the mid rage. If I give more, I see the timing pull to like -1 and stay -1 for a while and cilimb back up slowly. And it happens very randomly just like your case.( 2 out of 5 pulls). So, i tried more timing to see what happens. Then, it was consistently low( 5 out of 5 pulls). My suspicion is that konck voltage may not be relevant to ECU. it could be the spectrum in the frequency which is we don't know how Mitsu programmed to pick up.
Originally Posted by DynoFlash
Let me say this. . . .
I have been using my AEM now for over 2 years on my own car and also tuning AEM on various customer cars.
I was "trained" at AEM and feel I know my way around the softwear very well.
Still, there are certain "bugs" or "issues" which I have come across with that softwear and had to either plug away at it or ask for help to resolve the problem.
Interestingly, it was this very issue which lead me to take out the stock ecu from my own Evo. I first purchased evo flashing equipment for my own evo and it was only therefater I started to do tuning for others and start doing it professionally. Sadly, I never took the time to resolve this timing issue on my own car with the reflash equipment as the much easier path seemed to be just put a AEM in it.
Ironically, when I first proposed a colaberation with Buschur I was forced to confront this timing problem and it was Buschur who assisted me in solving the puzzle along with Tadashi of Techno Sqaure also offering pieces of the puzzle.
I have been using my AEM now for over 2 years on my own car and also tuning AEM on various customer cars.
I was "trained" at AEM and feel I know my way around the softwear very well.
Still, there are certain "bugs" or "issues" which I have come across with that softwear and had to either plug away at it or ask for help to resolve the problem.
Interestingly, it was this very issue which lead me to take out the stock ecu from my own Evo. I first purchased evo flashing equipment for my own evo and it was only therefater I started to do tuning for others and start doing it professionally. Sadly, I never took the time to resolve this timing issue on my own car with the reflash equipment as the much easier path seemed to be just put a AEM in it.
Ironically, when I first proposed a colaberation with Buschur I was forced to confront this timing problem and it was Buschur who assisted me in solving the puzzle along with Tadashi of Techno Sqaure also offering pieces of the puzzle.
Al, I don't doubt your skills. I myself have been using AEM EMS since they first came out (4-5 years ago?) and was involved with figuring out many of the initial bugs in the early software (V .73?) I also was involved in hacking & tuning the Ford EEC-V computer back in the day, which ironically is very similiar to what we are doing today with the ECU Flash software. The EEC tuner & TwEECer are windows based GUI and serve the same purpose as the current ECU Flash stuff (modify the factory code).
Unfortunately this is the first time I've seen this problem and I've flashed and tuned a lot of stock ECU cars. One thing I do on the dyno is that I don't do one glory run to show huge HP, but do multiple runs in a row to verify that the car is running corecctly and not jumping up and down with HP. Of course after 3 pulls back to back the hp drops slightly (a few hp) becuase of heat soak but I monitor timing and make sure nothing goofy is going on. Again any good tuner will make sure his tune is consistant in different conditions. Have you guys seen F1 teams/engine builders dyno an engine? They simulate complete laps of a circuit on the engine dyno!
Anyways, back on topic. We have to keep the facts straight and follow a logical path to diagnose what is going on. This could be the same problem that Al has found and if it is them I'm sure he has put some time into it and don't expect him to devulge info that he's put a lot of time into. I've spent many a nights digging through hex code in Techtom to find maps and I know it's tedious work.
Please be carefull of what each of you post and read each post so we don't have conflicting information and questions. If you think you found something make sure that it's correct information and how you verified it so we have solid facts.
I will start a post stating current facts and a bried description of how they where verified. Then we can add to this to compile good data.
-Martin
EVO8 PR
It seems your knock voltage jumped up in that area. Again we need to be comparing apples to apples. I'm not sure how the ECU+ works but we are modifying the factory code and making the low octane and high octane timing maps for experimentation purposes to see why timing is going lower than specified. What you are seeing is possibly the ecu pulling timing due to excessive knock noise.
The cam trigger wheel is in correct phase BTW.
It seems your knock voltage jumped up in that area. Again we need to be comparing apples to apples. I'm not sure how the ECU+ works but we are modifying the factory code and making the low octane and high octane timing maps for experimentation purposes to see why timing is going lower than specified. What you are seeing is possibly the ecu pulling timing due to excessive knock noise.
The cam trigger wheel is in correct phase BTW.
THE FACTS
Why is timing being pulled and or varying with the stock ECU flashed? We have the low octane and high octane timing maps the same for experimentation purposes only and we're running 109 oct. gas for safety.
1. IAT - varied from 85 deg to 140 deg and did not correlate to timing changes
2. Coolant Temp Sensor - varied from 185-195 and did not correlate to timing changes
If you unplug the temp sensor, ECT goes to -40 degF and the ECU throws a code and automatically pulls more timing.
3. Knock Sensor - removed the knock sensor from the block and isolated it from noise and did not correlate to timing changes. This problem does not correlate to knock sensor output!! this is very important! If you unplug the knock sensor it throws a CEL and also removes some more timing.
I'll keep updating and editing this post as we pinpoint more information.
Why is timing being pulled and or varying with the stock ECU flashed? We have the low octane and high octane timing maps the same for experimentation purposes only and we're running 109 oct. gas for safety.
1. IAT - varied from 85 deg to 140 deg and did not correlate to timing changes
2. Coolant Temp Sensor - varied from 185-195 and did not correlate to timing changes
If you unplug the temp sensor, ECT goes to -40 degF and the ECU throws a code and automatically pulls more timing.
3. Knock Sensor - removed the knock sensor from the block and isolated it from noise and did not correlate to timing changes. This problem does not correlate to knock sensor output!! this is very important! If you unplug the knock sensor it throws a CEL and also removes some more timing.
I'll keep updating and editing this post as we pinpoint more information.
