L98 engine temperature sensor
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
The one on the left is a Thermo Time Switch. This is used for the Cold Start Injector. This switch is closed for 8 seconds on a cold start and then it is open for the rest of the time.
The one to the right is the Coolant Temperature Sensor, this sensor reports directly to the ECM.
The one to the right is the Coolant Temperature Sensor, this sensor reports directly to the ECM.
Drifting
Joined: Aug 2010
Posts: 1,704
Likes: 8
what year is your L98? in 89 no longer cold start injector.Ceck if you have the CSI in the driver side of intake manifold...may be previous owner upgraded the chip (165) to late firmware with the injector deleted and simply disconnected the wire...without the thermo switch you must have an hard cranking start up.
Drifting
Joined: Aug 2010
Posts: 1,704
Likes: 8
if it is a 91 ,it is a speed density no MAF no CSI,probably previous owner changed the intake manifold using a previous 85-88 intake,just disconnected fuel supply to CSI and no wire at CSI connector.Probably he changed the intake becouse of porting it,or a damaged original one.
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
if it is a 91 ,it is a speed density no MAF no CSI,probably previous owner changed the intake manifold using a previous 85-88 intake,just disconnected fuel supply to CSI and no wire at CSI connector.Probably he changed the intake becouse of porting it,or a damaged original one.
And to answer the OP's question about where the wires go, the thermo time switch does not connect to the ECM at all. You can see how it works in the diagram.
This diagram is for a Camaro from Thirdgen.org, but it's basically the same thing.
http://92b4crs.tripod.com/86wiring/dia-pics/22-4.jpg
