Hello all, I have a 1986 Z28 5 gear t-top that now has a 350 carbureted. 305 Engine was swapped, sub frame connectors put in. Just got it and know very little history. Fixing lots of little things, when I put new dash bulbs in the service engine soon light is always on with new bulb lol. What triggers this light? I can’t see an original carbureted 305 having a computer or anything? The new 350 is mild performance upgraded, 330 hp, headers, cam, intake, etc but definitely no emissions and such exist. i don’t know where to start other than to disconnect the bulb again. Thoughts?

 

Did you pull the codes?

 

If the carb and dist aren't the computer-controlled originals, the light will be on forever. (ish)

Take the bulb back out.

 

nope. Not even sure how to pull the codes but I think it’s probably a waste of time anyway as everything has been modified from original.

 

Right: the original carb and dist were computer-controlled. If you have something else in it now, the light will never go out, unless you remove the bulb driver or the bulb.

 

I pulled my bulb driver on my 85, cleared it right up. I also pulled the entire ecm and harness

 

The original carbureted 305 was computer-controlled; a failure in any component governed by that computer will cause the SES light to come on. Since, as you state, all such original equipment has been removed, that light is now irrelevant. As already mentioned, simply remove the bulb, and go on your way.

Of course, when/if a problem with the engine occurs, you'll no longer be able to pull codes to assist you in troubleshooting. You'll also be dealing with a modified, non-standard wiring harness.