Has anyone out there (Nadir or Jeremy? ) got a list of the different voltages that the ECU will see at different vacuum readings?
I'm considering using the stock MK1 MAP sensor on my Mk1.6 but need the spec for the ECU. It's either that or shell out £50 on a Marelli 03/04 MAP sensor which the ECU already has the data for.
Part No. is 89420-17020 I think.
Techy question re Mk1 MAP sensor
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Re: Techy question re Mk1 MAP sensor
i did some tests on mk1 a and b map sensors a while back. now ill have to double check but the mk1b map sensor reads from vaccum to 3/4psi positive boost. working between 0.3 and 4.7v but ill have to double check hope that helps.
4agte on the way
Re: Techy question re Mk1 MAP sensor
Cheers Neil, what I need is a number of mV readings at different pressures so that I can plot a graph and from the equation of the line work out the specific entries for my ECU.
I've done this with the Mk1 air temp sensor and got y=-43.819x + 4435 where y=mV and x=air temp. I need to add a few more readings to the graph as I only have points between 19 and 50 degrees C. I'll be doing the same with the water temp sensor from the MZ. So far the readings have had a linear trend which has simplified things somewhat.
I've done this with the Mk1 air temp sensor and got y=-43.819x + 4435 where y=mV and x=air temp. I need to add a few more readings to the graph as I only have points between 19 and 50 degrees C. I'll be doing the same with the water temp sensor from the MZ. So far the readings have had a linear trend which has simplified things somewhat.
Re: Techy question re Mk1 MAP sensor
Vacuum, Voltage drop
100mmHg, 0.3 - 0.5V
200mmHg, 0.7-0.9V
300mmHg, 1.1-1.3
400mmHg, 1.5-1.7
500mmHg, 1.9-2.1
Source: 4AGE repair manual
getting close then
100mmHg, 0.3 - 0.5V
200mmHg, 0.7-0.9V
300mmHg, 1.1-1.3
400mmHg, 1.5-1.7
500mmHg, 1.9-2.1
Source: 4AGE repair manual
getting close then
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Re: Techy question re Mk1 MAP sensor
Cheers John. Will stick those numbers in the ECU and see what happens.
Not too far to go now.
Not too far to go now.
Re: Techy question re Mk1 MAP sensor
Big ol' bump for those that are interested I've fitted a Vacuum gauge (101-90kPa) to my MAP sensor and got some pretty accurate readings of the voltage seen by the ECU.
I may try to get a gauge with a wider range at some point but for the moment the conversion equation is y=30.349x + 511.49 where y=mV seen for a vacuum of x (kPa).
Pic of the graph plotted:
Edit: forgot to adjust the barometric pressure at the time so ignore the equation on the graph.
I may try to get a gauge with a wider range at some point but for the moment the conversion equation is y=30.349x + 511.49 where y=mV seen for a vacuum of x (kPa).
Pic of the graph plotted:
Edit: forgot to adjust the barometric pressure at the time so ignore the equation on the graph.
Re: Techy question re Mk1 MAP sensor
...only joking Chris hoho!
well I'm interested wow. bet you weren't expecting it to be quite that accurate! and it's pretty arrow straight, you should be able to extrapolate the full range from that pretty safely. hmmm I wonder how barometric pressure compensation works then..?
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