FI Question

bill

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On a 74 CSi, is there supposed to be a coolant temp. sensor located on the hose going into the bottom of the radiator? On the car I'm looking at, the sensor is there but it is not connected.How would that affect engine operation? Thanks for the help.
 

MMercury

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On a 74 CSi, is there supposed to be a coolant temp. sensor located on the hose going into the bottom of the radiator? On the car I'm looking at, the sensor is there but it is not connected.How would that affect engine operation? Thanks for the help.

I am not sure how this is a fuel injection question. I am no expert. I am not aware of any temp sensors that were originally fitted to an E9 d-jetted radiator and can't fathom what function they might have other than to trigger an electric fan. That doesn't mean there weren't exceptions as there were some early L-Jet systems (with airflow meter) used on the Si sedans.

You can peruse the parts diagrams yourself. I suspect you have a radiator design from a later M30 vehicle, such as an e24 (below), since those can be adapted to fit. If there is nothing to hook up, its merely dead weight and a non-issue.
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Peter A.

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Bill,
The sensor you are referring to is screwed-into the bottom of the radiator. It has connections for two wires. This sensor is part of the air conditioning system. I believe it was unique to ’74 & ’75 coupes.
Peter A.
 

bill

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Thanks Pete...that solves one mystery, but creates another: my 74 CS has AC (doesn't work), but there is no sensor on the radiator! But, I'm glad to know the sensor on the '74 CSi I'm looking at is NOT part of the FI system.
 

Peter A.

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Bill,
Your sensor may have been removed and filled with a bolt having the same thread. Maybe,
the previous owner substituted a '73 radiator. Pre-'74 coupes don't have this sensor and have different wiring harnesses. I believe the sensor was wired to the A/C fan at the front of the car.

On a '74 coupe I believe there is an A/C fuse near or under the battery tray. It's a glass-tube type of fuse. This fuse is enlosed in a black, twist-open fuse holder and may be part of the main wiring cable.

Regards,
Peter A.
 
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