Timing and smog emission 1988 Toyota 4-runnner

In the past I have timed my car to spec. in order to pass the California smog which causes it to run rough but it would pass smog and then I would “retime” it to actually drive it.

I tried it again this year but it doesn’t run well enough to move the dynamo. The drive train was rebuilt four years ago. And I’ve replaced the brakes, radiator, muffler and tailpipe in the last year and the truck runs fine except when timed to spec. for smog testing. Any suggestions ?

Have you checked to make sure the distributor is working right? I had to replace the distributor in my 1990 Toyota P/U when I noticed the timing was way off, and not advancing properly. Turns out, the advancing springs broke, and the plate had gotten corroded, and sticking at full advance. This caused all kinds of weird driveability problems. Also, are you sure the timing belt/chain is in good shape, and not jumped a tooth/cog? I’m asking this way, because I’m not sure what engine option you have.

But it seems something is amiss if setting it to spec causes poor running.

When you alter the timing are you shorting the test connector plug before doing anything? Failure to do this means you’re nowhere in the ball park with it.

I’ll be checking it out – thanks.

I didn’t know to do that before. Thanks.