My neighbour is a car mechanic, so, I'll try with its equipment used for testing the pressure/depressure of turbochargers.

Yes, I'll create an homemade "Y" connector in order to measure the vacuum and keep the hose connected to the MAP.

So, parallel measurement, MAP // Gauge.

Cruiser,
instead, if during Renixlog running in my laptop, at Idle and HOT,
I try to "pinch" the vacuum hose between MAP and throttle in order to
"change" the measurement, are there the possibilities that the ECU switch in
Closed Loop?

It's a way to "deceive" the ECU, so for the ECU seems to have a correct MAP value


Lucio.

 

I'm not sure about that. Try it and let us know.

 

Hello Cruiser.

I disconnect MAP connector, and I connected a variable (0V to 5V, with 0.5V steps) voltage regulator to the ECU-MAP connector,
in order to emulate the MAP OUTPUT and read KPA values using
Renixcom.exe

0V 0kpa 0Hg
0.5V 9.5kpa 2.8Hg
1V 20kpa 5.9Hg
1.5V 31kpa 9.1Hg
2V 43kpa 12.7Hg
2.5V 54kpa 16Hg
3V 66kpa 19.5Hg
3.5V 76kpa 22.4Hg
4V 88kpa 26Hg
4.5V 100kpa 29.5Hg
5V 110kpa 32.5Hg

Instead (always Engine OFF / Key ON),
If I reconnect the ECU-MAP connector (Engine OFF / Key ON)
the OUTPUT voltage is 4.5V, so means:
4.5V 100kpa 29.5Hg

Tomorrow I'll try to leave at IDLE the engine with the ECU-MAP disconnected and connected to the Voltage Regulator, in order to emulate the MAP voltage.

I want to understand If I'm able to enable the Closed Loop at IDLE.
If this will work with voltage variation, so the MAP sensor for sure is BAD.

The last thing to do is the physical measurement of the vacuum with the gauge as you suggested.

Attached you can find my throttle body and the two holes.
Only one goes to the MAP (bottom one).
The (top one) is closed, and seems that there is something like glue in order to keep it closed.
I've to remove the glue and keep the hole free on the tap?

Is this right?

Regards,
Lucio.

 

That is correct in the photo.

What is all that black goo?

 

Sorry Cruiser54,

i didn't understand what is the black goo.
:-)

 

Up above the arrows. Silicone?

 

If you refers to red arrows, YES. (Upper Right corner)

The intake "gum" was broken, but no air leak (checked 100000 times :-) )

Cruiser, there is also silicone in the hole not used (1st arrow).
I've to remove IT?

 

As long as the integrity of the throttle body to MAP hose/pipe is good, you are fine.

That connection is troublesome. that's why I wrote this:

http://cruiser54.com/?p=280

 

Yes, checked.

I'll do the same with a new and direct point to point connection as your solution.

Tomorrow I'll try to emulate the MAP voltage at idle and check if there is a voltage value that is able to put the ECU in closed loop.

If this will work, I'll change the MAP sensor.

 

Hello Cruiser54,

I've an update.

Checking my EGR, the EGR transducer piece is missing.

My EGR is directly connected to the EGR solenoid, but without the transducer. (see green arrow and green comment)

Attached you can find a picture where I indicated (red) the missing part.

Probably the previous owner removed IT.

Do you think that this can impact the idle and running?

Without the transducer (EGR connected directly to the solenoid) is
not enough to operate, right?

Regards,
Lucio.

 

If you are concerned about that, just disconnect the vacuum source for testing purposes.

 

SOLVED!!!!
I replaced the Renix ECU with another one (used) and now the battery voltage measured by the ECU is 14V (instead of 4.6V).

My ideas were right: an internal ECU component damaged.
Cause: alternator + voltage regulator fail --> overvoltage --> ECU damaged (but operative)
Corrective Action: ECU replaced --> WORKS.

Now goes in closed loop very immediately and it's perfect.

Below a screenshot of the ECU diagnose with RenixCom software.

Thanks to everybody for the support!!!