Question Hi, I am trying to get my girlfriend's Tercel ready to smog. She has a 1987 5-door hatchback made in the second half of the model year. It has a 3E 12-valve engine and an automatic transmission.
My Haynes manual says I can jumper the T and E1 terminals in the diagnosis check connector, and then observe the Check Engine light. Her car, however doesn't appear to have a Check Engine light (I can see the dash lights when they are not illuminated). And the connector only has three terminals which appear to be labeled Ox, E1, and VF.
Annie took the car to a test-only station and it failed the emissions test at 15 mph by exceeding the NO limit. It passed all other tests except the ignition timing test.
I have since replaced the front exhaust pipe and the muffler, both of which had giant holes in them, and replaced the oxygen sensor. I cleaned out the EGR valve. The EGR vacuum modulator filter looked OK. I tried to adjust the idle speed. It idles at around 2200 rpm cold and 1400 rpm hot. The sticker says it should be 900 rpm hot. I have adjusted all the idle screws but the throttle positioner(?, it looks like two flying saucers stuck together, one on top of the other) seems to be holding the throttle open. I haven't attempted to adjust the ignition timing yet.
My questions are, how can I use the diagnostic system, and what do you think might be causing the idle to be so high?
Thank you, Paul from Oakland
AnswerThe ignition timing will affect nox emissions reading, this is the first thing you should do, set the timing.
This emission control system can be a real pain, it has lots of vacuum hoses and sensors etc. I'm not sure why the positioner is holding the throttle open, could be a vacuum hose mix up.
There should be a check engine light and also the T1 connector, the E1 is the ground side of the ECU, I have never encountered a tercel of this year model that does not have the check light or connector so I can't help with that.
