A610 turbo boost gauge again

Hi

Re my post on the full reading on the boost gauge.I have changed the boost sensor supplied kindly by clee but unfortunately the gauge still reading full boost as soon as ignition switched on(actually it is reading about 4/5 ths full boost)
I cannot imagine that two sensors are faulty so please any one with any suggestions will gratefully try


Dave g

Hi

have been trying to fathom out this boost gauge sensor without success.
Is it's only function to feed the boost gauge or does it do something else as well?


Thanks Dave g

.
Hi Dave,

The sensor only feeds the dash gauge, plays no further part in proceedings. I have not played with A610s from this aspect, but I know the ecu, and the same gauge used on the GTA. Given I'm always short on manifold pressure sense connections, I always end up sacrificing the boost gauge and removing them; leaving the connector simply disconnected, and the dash gauge always reads zero.

Don't know if that helps.

Martin

Hi Dave,

The Boost gauge is an electrically driven item from the pressure sensor .... item 342 ... see below.
I have checked the circuit for the gauge and it is pretty simple.
!2v are supplied to one side of the Boost Gauge, and the other side of the gauge goes straight to the pressure sensor, through it and straight down to earth.
What I would do is ... with ign on and the gauge reading full scale, unplug the sensor, and the gauge should drop to zero. This is what I suspect will happen. If that is the case ... replace the sensor.
If, however the gauge stays at full scale, there is a "short to earth" somewhere between the gauge and the sensor, possibly in the sensor connector its self.
Hope this helps.

John

Dave ....... Did you ever do this simple test ???

Hi John


Yes I did unplug the sensor and yes the gauge dropped to zero I then got another pressure sensor from clee and that is the same, full boost when plugged in and zero when unplugged .I feel the likelyhood of two sensors being defective unlikely so am open to any other suggestions.
Have been offered a complete instrument pack but will have another play to see if I can find the fault.



Thanks Dave g

Yes I did unplug the sensor and yes the gauge dropped to zero I then got another pressure sensor from clee and that is the same, full boost when plugged in and zero when unplugged .I feel the likelyhood of two sensors being defective unlikely so am open to any other suggestions.

Hi Dave,

I am afraid this really points to defective sensors.
Correct me if I'm wrong, But you said that on the original, the needle went to "Full Boost", but on the replacement it went to 4/5ths of "Full Boost", if that is correct it does point to faulty sensors ....... if they had read the same, there could be some other reason ..... but I doubt it.

John

PS ..... I don't know, but it might be worth it, to try washing out the section of the sensor that the pipe is connected to with petrol, or similar, just in case there is some gunge in that section which is stopping the diaphragm from flexing under changing pressure. ........ just a thought.

I'll see if I have another sensor Dave .Does sound like that one is dodgy also .

Hi John

re full then 4/5ths boost on gauge sorry for the confusion it read 4/5 on original sensor and the same on replacement sensor
Re washing out with petrol, sucking on the little pipe I can here the diaphragm moving
Any way of testing the electrical side of the sensor ,there is no resistance over the 2 end pins neither on the middle pin and the end pins and applying a vacumn does not alter that .Not being leccy minded but it would appear that the whole thing is faulty
that is the original one .
Hi Lee another one to test would be good.

Thanks Dave g

another on it's way ,fingers crossed

Hi John ........... Any way of testing the electrical side of the sensor ,there is no resistance over the 2 end pins neither on the middle pin and the end pins and applying a vacumn does not alter that .Not being leccy minded but it would appear that the whole thing is faulty

The only way you can really test it is by resistance comparison with a known good one.
There is little more I can add, as I have said before, it is a very simple circuit. But something does puzzle me ..... you say the connector to the sensor is a 3 pin one. The circuit shows the sensor needing only 2 wires, one going down to earth and the other going to the Boost Gauge. Do all 3 pins have a wire attached, or is it a 3 pin connector with only 2 of the pins having wires ???
One more thing you could check ..... with the ign switched on and the sensor disconnected, there should be 12v on one of the pins coming from the dash board gauge (when testing the gauge will remain at zero)
John

Hi john


will be pulling it apart again and will check the wires see if two or three ,definately the socket is for three pins and there are three pins on the sensor .Clee is sending me another sensor so hopefully might be the answer.
I presume that one of the wires to the socket will be live so will check that as well.
will post findings although might be a few days till I get time
Thanks


Dave g

Just a quick update on this as I finished the resto a fair few weeks back ,horrendous rot but now all good
Fault was with the gauge itself not the senders and a quick fix in the end ....apart from taking it all out ...even worse putting back in ...they really do squeeze them there delicate wires in

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