Check Engine Light

[Tritium007]

I recently replaced plugs, wires, and cap. The old plugs were slightly colder than called for and must have been installed by PO. Replaced with correct ones. Now the Check Engine Light comes on at idle and goes out when cruising (auto trans). I thought maybe after a few tanks of gas the ECM might adjust but after reading through another post it occurred to me that the primitive ECM's aren't capable of this feature. My question is: will diconnecting the battery to reset the ECM correct this condition? No performance issues or stalling, just the annoying light.

 

[Sensei]

Disconnecting the battery will re-set the ECM, but may or may not fix the problem?

God bless, Sensei

 

[RC81]

Mine used to do that until I got my carb dialed in, and a varying dwell within specs. Check your dwell and tps voltage setting.

 

[bill81vette]

Pull the D#@$ bulb!!!!

 

[redvett]

Read the code and fix the problem.

 

[golfradict]

Check engine light

Hey Tritium007, did you find the source of your check engine light problem? My 81 does the same thing, I have a new ECM and a freshly rebuilt carb, the engine runs and idles real smooth, my check engine light will come on when at idle then stay on for about 10 mins., then it will go off. :confused

 

[6880 Mike]

Read the code and fix the problem.

I agree.

 

[Peer81]

Check the code and fix the problem!

Greetings Peter

 

[golfradict]

Hey Tritium007, did you find the source of your check engine light problem? My 81 does the same thing, I have a new ECM and a freshly rebuilt carb, the engine runs and idles real smooth, my check engine light will come on when at idle then stay on for about 10 mins., then it will go off. :confused

Shortly after posting this I checked the code, it was the coolant temperature sensor, got a new one from NAPA, problem solved.

 

[GerryLP]

I agree as well. Read the code and follow the isolation procedure for that code.

It just happened to me as well. I got a code #15, Shot the wires all the way to the computer and found no open wires. Ohm'ed out the coolant temperature sensor, and it was less that 1,000 ohms (about 265 or so). I just ordered a new ECM IAW procedure, but I suspected it already for she was running rich and the needle would not vary on the Dwell gage. ;squint:

GerryLP:cool