MAT Sensor

[Enright]

Most will already know that the Isuzu Impulse RS Turbo shares it's engine with our beloved baby, but I am astonished at just how much cheaper parts are.

I just found this site: www.rockauto.com

It has a searchable java parts catalogue that goes right down to very small components.

For instance, I just placed an order for a Manifold Air Temperature Sensor for $18.54 + shipping - absolutely brilliant compared to good old Lotus dealer prices.

[ESM]

On this subject here is the GM part number and the calibration graph for the MAT sensor

[Enright]

Wow Alan, that is an absolutely GOLDEN find!

So if (as I suspect) I have a CTS and MAT that are having a punch-up and screwing up my performance, all I need to do is get a cheapo thermometer, some hot and cold water, and a multimeter.

Then I just measure the readings, and if they are out of tolerance, replace the sensor. Fantastic. Thanks.

[nitroman]

Enright, on Rockauto.com I select the 1991 Isuzu Impulse RS, then select "Emission", then there are two listings but I'm not sure which is the right one.
1) Air Temperature Sensor
2) Intake Manifold Temperature Sensor

Could you please tell me which one of those two is our MAT sensor? Thanks.
PS - Others, please don't order the last Beck/Arnley one, as hopefully I can get that one.

Most will already know that the Isuzu Impulse RS Turbo shares it's engine with our beloved baby, but I am astonished at just how much cheaper parts are.

I just found this site: http://www.rockauto.com

It has a searchable java parts catalogue that goes right down to very small components.

For instance, I just placed an order for a Manifold Air Temperature Sensor for $18.54 + shipping - absolutely brilliant compared to good old Lotus dealer prices.

[saska]

Enright, on Rockauto.com I select the 1991 Isuzu Impulse RS, then select "Emission", then there are two listings but I'm not sure which is the right one.
1) Air Temperature Sensor
2) Intake Manifold Temperature Sensor
Could you please tell me which one of those two is our MAT sensor? Thanks.

The Intake Manifold Temp Sensor has part numbers ACDELCO Part # 213192 and also 25037334
The Air Temp Sensors ORIGINAL ENGINE MANAGEMENT Part # ATS4 and STANDARD MOTOR PRODUCTS Part # AX1 cross reference to the above ACDELCO part numbers (under INFO)
Think any of the above 3 parts will be fine -- the different listings appear to be nomenclature differences for the same item. Lotus actually refers to the MAT differently to the 2 Rockauto terms, it is a Mass Air Temp sensor in the closed loop manual.

[nitroman]

I only replaced the MAT sensor to begin as it's far easier than getting to than the CTS. That alone has solved the problem but it "fixed" MUCH more than anticipated. The car starts in a nanosecond now and idles so smoothly that you no longer feel ANY sense of engine vibration resonating through the chassis. For the price I'd have to recommend replacing this item even if you don't feel you have a problem, as the old sensor "probe" extending within the manifold was filthy. Not rusty or corroded, just filthy dirty.

This is the item I ordered: http://www.bmotorsports.com/shop/produc ... cts_id/400 It is an EXACT match for the old part except the color of the plastic is a lighter shade of grey and the probe is painted black instead of dark blue. It looks EXACTLY like the picture.

[DeanG]

I think that you are correct in that a few new sensors and possibly a fresh battery can fix a lot of issues with our cars. They are all getting to be 20 years old.

At a lecture on Esprit maintenance by the national service manager it was suggested that if you have odd problems with an Esprit that a fresh battery would often do the trick.