M48 - Porsche 914 v8

[erwan914]

Hi,

I bought the Porsche 914 presented at the following link and it is equipped with a M48:
http://www.v8914.com/Engine.htm

But I need help to adjust the FUEL table because the car is too lean and jerks when accelerating, and is too rich at low speed with black smoke. And also with rough idle.

Some could help me please ?

[David Ferguson]

You're going to need to find an old laptop with a serial port, and download the M48 EMP software found here:

https://www.motec.com.au/software/latestreleases/

That software runs in DOS. You will need the special Comms cable that converts the TTL level serial signals to RS-232.

That said, this is likely a project that should be upgraded to a newer more supportable ECU. At a minimum an M84, but if you really want to give it a long life, probably an M130 w/ GPA or GPR would be best.

I suggest you contact a local MoTeC dealer to discuss. Look here for dealers (UK and Europe), change region at the bottom of the webpage to see others):

https://www.motec.com.au/dealerssection ... ukireland/

They will likely have experience with the older systems and could certainly help you update to something supportable for the future.

Looks like a nice project -- Good Luck!

[erwan914]

Thanks David for your advices. I will try to contact the local dealers in Europe as you suggest.

As you said, I have managed to run the M48 software with an old laptop on W7 and with a suitable cable.
For information, when you speak about upgrade, it's just a software upgrade ? or an hardware upgrade ?

[David Ferguson]

It would be both a hardware and software upgrade. There have been a lot of advances in the last 20 years!

[erwan914]

Photos and M48 screenshots
https://photos.app.goo.gl/AmAJFhfhFhJD2T587

[erwan914]

FUEL_MAP_Data.png (31.35 KiB) Viewed 17412 times

Fuel Map data

[erwan914]

FUEL_MAP_914.png (48.6 KiB) Viewed 17412 times

Fuel Map 3D Curve

[erwan914]

This fuel map was created by a company with the car on a rolling road.

[David Ferguson]

My suggestion before changing the fuel map:

-- verify that all the sensors are providing reasonable values (engine temp, fuel pressure)
-- particularly check the Throttle Position for smooth operation and that it's calibrated 0-100%.
-- verify the CrIP (i.e. commanded ignition timing equals actual ign timing)

When all that's good, then you need to determine where the engine is operating when you experience problems. The M48 does have logging and you should be able to use the Interpreter program to view those logs.

To properly tune the fuel, you will need some wideband lambda data -- I don't remember if the M48 had that, or if it would be possible to connect an external wideband to one of the M48 inputs so that data was logged.

[erwan914]

Hello David,

Thanks for your advices.
I did a lot of checks last week and I think that there is a problem with fuel pumps. The fuel pressure when accelerating is not consistent with a normal functioning. So I will investigate...

I have ajusted the throttle position and the idle is good now.