Check engine light

[jonlabree]

I have a supercharged 1990 buick Reatta. The engine has been modified. Ported & polished heads, supercharger, intake manifold,& throttle body.

Supercharged rods and pistons and a GN crankshaft.

My problem is the check engine come on whenever it pleases. I know that it is caused by the  air temp sender. I have tried to move it nearer the 

throttle body and also farther away, but it still comes on whenever it pleases.

Can anyone tell me a cure?

Jon...

[95Cardinal]

If the sensor checks out OK, you might have an intermittent open or short in the harness or the connector.

Have you been able to test the sensor to confirm it works properly?

[jonlabree]

The sensor is new..

[NTX5467]

I presume you have verified via "code analysis" that it is the air temp sensor?  Is it "charge temperature" or "ambient temperarue"?

 

This sensor should not be that critical to the operation of the engine, but a "fine tuning" sensor of sorts, I believe.

 

Is it a new GM sensor or from another vendor?  Just curious.  Some of the aftermarket brands might not have the exactly correct terminals or could have different output information/voltage than a factory GM sensor . . . for what it's worth.

 

I'd compare the plug-in terminals with those of the original sensor (which you might have already done).  The put a scan tool on the engine and watch the values from that sensor during engine operation.  When the light "trips", then punch "the button" and get a snapshot of what that sensor (and others) were doing when the light was triggered.

 

Can't rule out a degraded terminal in the wiring connector, or degraded terminal/wire connection, either!  The GM connectors are pretty easy to disassemble for terminal repairs and such.  It's all about voltages, resistances and combinations thereof.  If something's not "right", the light comes on.

 

Please keep us posted on your progress.

 

NTX5467