GTASHARK

Impressive. Can we expect an EZK replacement next?

hacker-pschorr

Any photos of the computer screen?

Ed Scherer

I quickly hooked up my 'scope and got the following.

I've still got everything set up in the garage and can leave it that way for another day or so, so if you want anything more, just ask; it'll be easy to provide more info.

Notes:

• car is my '90 928 S4 (which does, in fact, "work" )
• upper trace is LH pin 1 "EZK speed pulse" (actually probed at CE panel W11)
• 0 V for the upper trace is in the middle of the upper half of the grid
• lower trace is LH pin 18 "fuel injectors ti" (actually probed at CE panel W12)
• 0 V for the lower trace is in the middle of the lower half of the grid
• x axis is either 10 ms/div or 20 ms/div (see each photo)
• y axis is 20 V/div

~675 RPM, x axis is 20 ms/div:




~1000 RPM, x axis is 20 ms/div:




~2000 RPM, x axis is 10 ms/div:




~3000 RPM, x axis is 10 ms/div:




~4000 RPM, x axis is 10 ms/div:

Volla

Brittiant! Thanks for the scope pics. That is exactly what I wanted. I think I have everything I need, but I wont hesitate to contact you if i need anything similar.

I am busy with the coding at the moment, will upload another video when I have something again.

==================================================
19?? VW Baja Bug (Completely custom, Golf 1.8 motor, and many, many mods) - Currently my daily drive
1988 Porsche 928 S4 Euro/ROW (Black with Ivory interior) - Under ECU surgery
1982 Porsche 924 Euro (Silver with cream interior)- Gone
1982 Porsche 928 S (Manual) Euro (Petrol Blue with Blue with black and white chequered interior) - Gone
1983 Porsche 928 S (Auto, NA spec, Red, black interior) - Gone
1994 BMW 530i Manual (Maroon, grey interior) - Gone

smiffypr

The LH ECU has some clever features which are not obvious unless you have read all the literature, like taking account of the longer time it takes injectors to open when the battery voltage is low, and having a limp-home mode to get you home if the MAF fails. Are you intending to incorporate all those features too?

Volla

Ok, I am not enitrely sure if the LH actually monitors battery voltage and adjusts the injector time, I wasn't able to find anything like that when I analysed my LH. But i can be wrong.

Either way, I can integrate support for that later on. I am planning a limp home mode for the ECU though. I will do that later on with the engine temp sensor and other stuff.

The windows side interface software is not yet written, that will come later. At the moment how I adjust the fuel map is by changing the values stored in the CPU flash manually through the ICD programmer/debugger.

Back to the update:

Step 7: Programming Phase 2: Fuel adjustment according to RPM

Ok, lets give the youtube link first then I will give my boring explanation.

http://www.youtube.com/watch?v=_HC11F8Bi80

In this video my setup is me sitting with laptop, connected to ICD3 connected to my ECU. The ICD3 in debugging mode allows me to stop and start the CPU when I want (in the bottom of the video on the pc screen you can see me click the run and pause buttons)

I have programmed the first part of my fuel map that looks in a 1 dimensional array for the injector opening time.

To calculate the RPM I use an internal timer on the CPU. The timer runs at half the CPU speed (40 MHz), along with a divider of 256 that I programmed in. This will yield a timer value of 156.35 for every ms. A bit of calculation later gives me a magic number of 11719. When I take the number 11719 and divide the timer value that measures the time between EZK pulsed, I get a nice 100xRPM value. (value of 5 = 500 rpm etc). Using this method I get a 0.002% error. Meaning I read 7000 rpm instead of 7000.149 (Personally I think this is close enough)

I then use that to look up in my table to get the injector opening value.

The next step is to program the unit to take the MAF into account. That will not be done today, If I am lucky (read: will not sleep a lot tonight) tomorrow the MAF will be sorted and I will post a video of me driving around the block.

==================================================
19?? VW Baja Bug (Completely custom, Golf 1.8 motor, and many, many mods) - Currently my daily drive
1988 Porsche 928 S4 Euro/ROW (Black with Ivory interior) - Under ECU surgery
1982 Porsche 924 Euro (Silver with cream interior)- Gone
1982 Porsche 928 S (Manual) Euro (Petrol Blue with Blue with black and white chequered interior) - Gone
1983 Porsche 928 S (Auto, NA spec, Red, black interior) - Gone
1994 BMW 530i Manual (Maroon, grey interior) - Gone

Mike Frye

Freakin' amazing.

Landseer

Damn.

Leon Speed

Ok I don't know what the heck you're saying in your posts but it is still interesting. Keep up the good work!

smiffypr

The description of the voltage correction is in a document called "Gasoline Fuel-Injection System L-Jetronic" which is included on the Morehouse set of 928 technical document CDs.

ROG100

This so way over my head - however I know someone who would love to sell the product if and when you decide to do that.
Roger

PorKen

Very cool stuff!

Replacing the EZF/EZK is where the real power is. Making a (single knock sensor input) EZK that would work on the S2/S3 would be sweet.

Both the LH2.2 and 2.3 modify the injector open time slightly according to the voltage coming into the LH.

Note LH2.3 outputs a frequency to the EZK based on the MAF voltage and RPM to indicate load. (LH2.2 also outputs this signal, but it is not used. The EZF has an internal MAP sensor.)

69gaugeman

Subscribing.

Volla

Mini update:

Ok, I got that book, quite a good read, in the end I will implement all the features described.

The coding has been going slow the past few days, will only have time to work on the code tomorrow and then the weekend.

Will keep everyone updated.


==================================================
19?? VW Baja Bug (Completely custom, Golf 1.8 motor, and many, many mods) - Currently my daily drive
1988 Porsche 928 S4 Euro/ROW (Black with Ivory interior) - Under ECU surgery
1982 Porsche 924 Euro (Silver with cream interior)- Gone
1982 Porsche 928 S (Manual) Euro (Petrol Blue with Blue with black and white chequered interior) - Gone
1983 Porsche 928 S (Auto, NA spec, Red, black interior) - Gone
1994 BMW 530i Manual (Maroon, grey interior) - Gone

GTASHARK

Thanks again for you work on this, the 928 community appreciates your efforts!