Split Second AFM To MAS Conversion (Split-Second / SplitSecond)

[iachella]

Good to hear they are all the same too. That at least eliminates more calibration. I'll have enough to do with using my own MAF.

Any easy way to test my old sensor? Certain resistance at room temperature, higher resistance sticking it in the oven, never zero, never infinity? Or never above a certain value?

[Craig]

G'Day Stefano,

See pic.


Eric, just to prove an exception to every rule, I have a sensor here from a Renault (I think) which is 300ohm at 29°C (and it's 5:40am on it's way to 40°C again ).


Edit: If you need something to convert °C to °F (and damn near anything to anything) I use convert, it's free.

[Razzo rosso]

Hi

Can anyone tell me the purpose of pin 1 of the air flow meter (0 280 202 202) from a series 4 Spider that connects to pin 30 of the Motronic ECU?

The diagrams from the manual are below.

Regards and thanks.

Simon

[Craig]

G'Day Simon,

From (failing) memory it's the CO adjustment pot. It's not used on the TS in closed loop and should be about 2.5V in open loop modes.

Will confirm later if no other replies.

[Craig]

Ok, I was right. This should answer a few questions.

[Razzo rosso]

Hi Craig

Thanks for the very quick reply. By the look of the circuit diagram, the ~ 2.5 volt signal is constant, no matter whether when the AFM is open or closed - or am I reading the circuit diagram incorrectly? It seems a little strange to go to all that trouble to create a constant 2.5V input.

With regards to switching from an AFM to a MAF such as discussed in this thread, does that mean a 2.5 volt signal should be created to tell the ECU to behave in open loop. Easy to do, but is it necessary?

Thank you very much for the advice.

Simon

[Craig]

Simon,

It's an emissions adjustment (brass screw under cap on AFM), CO at idle I think, measured at tailpipe.

2.5V is an approximation which probably should be simulated when replacing the AFM (but only Bosch really knows ).

[Razzo rosso]

... begs the question, what happens if you fiddle with it !!!

[Craig]

The CO emissions at idle change not much else.

[Razzo rosso]

Found this ...

CO pot
The CO pot mixture adjuster is a potentiometer that allows small changes to be made to the idle CO. A 5.0 volt reference voltage is applied to the sensor and connected to the AFS earth return circuit. The third wire is the CO pot signal. As the CO pot adjustment screw is turned the change in resistance returns a voltage signal to the ECU that will result in a change in CO. The CO pot adjustment only affects idle CO. Datum position is usually 2.50 volts. On catalyst equipped models, the CO pot has no effect and the CO is thus non-adjustable.

... at this site. www.opel-scan.ru/files/Opel_MotronicML4.1.pdf

[Craig]

Quote:

Originally Posted by Razzo rosso is thus non-adjustable.

[ToonRboy]

Since this thread seems to have died off, I take it noone has had much success. If you're going to go the Split Second route - which I believe to be one of the most cost effective and simplest route for GTV6/Milano owners, I would suggest you go with their MAF kit and the PSC-009 (which should address the fuel pump relay and intake air temp sensor issues with replacing the stock AFM).

Best regards,

[iachella]

From the wiring table, the only difference I see from the 004 to 009 is the fuel pump wire and the 8V reference wire for the higher signal AFMs. The air temp wire exists on both units. I don't see an advantage if your AFM is a 5V one, which the Motronic ones are. Motronic ECU has it's own fuel pump wiring too. Can you explain why you think the 009 is better than the 004?

I'm still planning on getting one soon. I am running an open loop system so I think I should get an O2 sensor welded in before I get one, so I can adjust. I haven't done that yet. I'm going to get some exhaust work done soon anyway since my cat seems to be disintegrating as a result of running open loop for about a year now. At first power seemed down, now power is good but there is a rattling from inside the cat. I'll run the O2 sensor to a guage I have so I'll have them make the new cat removable and make up a straight pipe for now.

So after all that work is done, I'll get the conversion unit. I have acquired a Ford MAF from the correct engine model, so I'm set there. I'll post results, of course.

[ToonRboy]

Quote:

Today 09:39 AM iachella wrote: Can you explain why you think the 009 is better than the 004?

[alpa]

Hi,

Still none positive experience ?

About AFM switches: L-Jet and Motronic AFM are very different. They don't use the same voltage (12v and 5v), they have different transfer functions and Motronic does not need the external security pump switch, it's integrated inside the ECU.