Not Passing emission's :-(
 

Hey Guys and Gals, First I should say that I have a 1991 Toyota Cressida with the 7MGE motor and since I really can't find Cressida forums I come here for your help. I just recently had to do a head gasket on the motor and am trying to get it to pass emission since it hasn't for about 3 years now. (not running for about 1 of those years.)
It seems to run great, but I can't seem to pass. it is way to high when idle and running with the test. I have swapped plugs wires cap and rotor, and i should say that it is clocked 10 degrees. Could this make it run high emissions? Have any of you run into this? What is the correct clocking on this motor? Should it be running at Zero? Could a coolant temp sensor cause this? idea's free things to try i'm down for this all. Let me know, thanks guys!!!!

Shane

Without knowing where it's failing you're not going to get anything but guesses....

Proper ignition advance timing is 10 degrees BTDC. Did you set this with the diagnostic jumper in place?

Yes, a bad coolant sensor can cause issues.

Have you checked for error codes? (See the first sticky in the MKIII FAQ)

Any mods to the car?

Is the air filter clean?

OK so in response to the above post,

There is no MODS done to the car at all, plan Jane.

what the car failed for
this is before new wires cap and rotor.
Cruise
HC / CO

150 / 1 Limit
286 / 7.12 Actual

Idle

220 / 1.2 Limit
303 / 4.09 Actual


After cap rotor and wires

Cruise
HC / CO

150 / 1 Limit
274 / 6.55 Actual

Idle

220 / 1.2 Limit
305 / 1 Actual


The air filter hasn't been changed and is dirty but would it screw it up that much? ^^^. If so then I'm a monkey's uncle.


I used a timing light to set the 10 degree on the crank pulley. what is this with a jumper business? so i have done it this way? and how?

there is no engine lights on, so i wouldn't think to check it. (i will ready sticky above).

Shane

Just a couple questions about the temp sensor. Have have a massive gobble of aluminum with like 2 sensors on it. 2 look the same one has green connector one has a white, are they the same? Maybe on is the sending sensor or what not. could this screw up my econ so much that it wouldn't pass? what is the ohm reading and how do I test it?

Shane

I don't have time right now to cover every aspect of this. There aren't many engine error codes which cause the check engine light to stay on... check for codes FIRST and stop guessing at things.

You'll find info on the ECU temp sensor in the contents on this page: http://www.cygnusx1.net/Supra/Librar....aspx?S=FI&P=1

When setting the ignition advance you have to set the diagnostic jumper (same one you set to check error codes) while adjusting the timing and the car must be at normal operating temp. (jumper TE and E1)

Why does the diagnostic jumper need to be in when setting the timing? Tried it still is the same.

Also that book referred to doesn't say much about the temp sensor. It shows that the temp sensor is the side one with green connector. If i do have a bad temp sensor would it screw up the fuel air mixture to the point of failing.

Checked codes and nothing kicks it, just keeps flashing and never stops.

Shane

P.S

Thanks for the help.

The jumper is there so that the computer will not advance the ignition timing, thus allowing you to set your base ignition timing. The car at normal operating temp is also very important...

If the ignition timing is in fact the same with the jumper wire in and with it out, then you may have an issue with your ignition control module (or igniter, as I believe most people call it). When you remove the jumper wire after setting your base ignition timing, the timing should automatically advance to around 12 degrees BTDC


A faulty coolant temp sensor could be telling the ECU that the coolant is not at operating temperature when it really is, so it may be adding more fuel to it. That could cause your car to run at a high idle, as well as increasing your emissions.

So setting it the timing with jumper in. do i set it to 0 on the crank pulley and then pulling out the jumper it will set it self to 10 degree or 12 what ever it should be.

The idle is at 780 most to all the time.

just answered my own question on the timing issue. sorry

If I just wanted to pass emission couldn't i turn to distributer up and call it a day?

Shane

still would be looking into the problem but at least i would have a decent running car to drive.