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TribesMac
20th March, 2011, 07:40 PM
I'm looking for any info about this ECU.

A friend of mine has done some crazy mods to his engine (higher compression ratio, different intake and exhaust manifolds, race camshafts, free flow exhaust, bigger throttle body, bigger airflow sensor casing...)

Now with this mods car is running awful, he was trying to get a remap at a local tuning company, but they said that this ECU is not worth working on, and that he should get a "racing electronics". But that is not the option at the moment, because of the time and money limitations.

The main things we would like to fix on his car is the idle (at the moment engine jumps from 600-1100rpms during idle) we would like to raise the idle to ~1000rpm, to fix this jumping.
We would also like to disable the lambda probes located after the catalysts. Those probes were removed from the car, and they make the ECU light to stay on.
And the third thing is to recalibrate the airflow sensor map. Airflow sensor is now mounted in bigger casing with ~40% higher cross section.

If anyone can help us with this we would be really grateful... Any kind of info. So far I have found only basic maps for ignition and injection... everything else is a mistery for me...

ECU HW and SW numbers of the Bosch Motronic ME3.1:
0261206660
1277356421

The original file from the car is attached...

oldford
21st March, 2011, 09:23 AM
I would let a professional make the setup on a rolling road.

Idle hunting is probably (also) caused by a wrong mixture.
You would also need to delete the front oxygen sensor, because of the overlap in the race cams. To much Oxygen entering the exhaust and fooling the Oxygen sensor. Will be quite difficult on the standard ecu with all these changes.
Get a decent aftermarket ecu before your friend blows the engine in a big way.

TribesMac
21st March, 2011, 09:54 AM
Thanks for your opinion mate!

I wasn't aware of those problems with race cams and oxygen sensors.
So I guess the local tuning company was right when they suggested that he should get a racing electronics... :/

oldford
21st March, 2011, 11:12 AM
I give the same advice.
Most people know how to change maps, but disabling front and rear oxygen sensor control is something entirely different.

You may need some bigger injectors too, if the increase in horse power is significant. Some aftermarket systems may not be able to handle an air mass meter, in that case you have to change to a map-sensor and a intake air temperature sensor.

One warning: depending on the laws regarding exhaust limits the car might fail an inspection because is has to much CO in the exhaust gasses. But it would fail now also.

TribesMac
21st March, 2011, 11:54 AM
The inspection is not an issue... The car is so far from stock that it could pass the inspection only with some green ones in the envelope (yes that is still possible where we live) :D

My friend is trying to achieve some 300BHP. Stock it 220... I have no idea if injectors are capable of that. Will see.

So disabling all oxygen sensors would probably mean that the car would always run in "open loop"? I guess this is not too big issue, as the cars usualy run open loop at higher loads, or am I wrong?

oldford
21st March, 2011, 12:47 PM
Running "open loop" is not a big issue, once it has been setup properly. Old cars (before the catalyst and oxygen sensor) were by definition "open loop".
Closed loop is switched off at higher loads with (at least) the majority of standard ecu's, so you are right there.

40% extra on standard injectors and probably more revs than standard (so shorter time available for the injection) may be a bit much for the standard injectors. Maybe even for the fuel pump.
Check how much fuel the standard fuel pump is giving.
200 liters per hour is the minimum, 250 would be better.

TribesMac
21st March, 2011, 01:06 PM
Thanks a lot for those tips mate! Very helpful!

AlexAlfist
14th December, 2023, 07:39 PM
Tell me, did the GTV have a VDC system?