Leaderboard

You can test the MAP sensor before you replace it. Make sure it has a 5V input and a ground. The middle wire should change voltage based on vacuum, although I'm not exactly sure what is what. Do you have a way to check what kPa the PCM is reading with key-on? OBD-II has a table for the maximum kPa allowed and if it's above that, it won't start. At least, that was what I determined with my GT. I had two new MAP sensors that were faulty out of the box. I have no idea, though, how OBD-I works with that. You can also hook up a vacuum gauge to the MAP sensor and make sure the voltage varies with vacuum.

As I said, the map may not be the primary issue, but the map may be the result of an issue, the ecm relies on ambient air temp & coolant temp to be able to properly calculate the needed fuel mixture. If the coolant temp sensor has either failed or the wiring circuit is questionable the ecm cannot calculate. The same goes for the IAT sensor, if the ecm isn't seeing the proper temp input from the sensor then it again cannot calculate the needed air/fuel ratio. The map relies on both of these signals functioning properly to adjust the proper air ambient pressure signal to the ecm.

Greg: this does sound like it might be a map issue, your description of the symptoms sort of point in that direction. If there is a map issue the ecm cannot configure the proper fuel mixture to get the engine to fire. Is there a check engine light on at all?.......(other than the usual code 12 when one turns the key to run) A faulty ecm coolant temp sensor sensor circuit can trigger a map issue. One needs a scanner to read (in real time) what the koeo reading for the ect circuit is (example...-49 degrees fahrenheit with the key on), that is an indicator that the ecm is not seeing the proper ambient temp the ect circuit should be supplying.

If you think a dealer will be of much help I have some oceanfront property in Nebraska. Most techs there if they aren't parts changers were only born when the car was new. OBD 1 may as well be hieroglyphics to them I've done a number of them. I'll be honest I'm hard pressed to think of a worse job on an Automatic LQ1 car. Step one, pull the alternator, that will give you the best access to it Step two, pray to whichever greater power you prefer that it comes out without a fight. Oftentimes they will split down the side, oil will get inside and the body will expand and get stuck in the bore. Absolute nightmare to get them out after that. It quickly goes from "lets remove the bolt and pull this out to" Def-con 5 prying and breaking out out piece by piece. My old Euro 3.4 I had to have messed with that stupid thing for a few weeks back in the day. I ended up getting a dremel back there with a drillbit and ripped it out with a drywall screw and vice grips. By the way did you ever verify timing?

Welcome!

Color and condition? Miles? If it's not currently running, how long has it been sitting? You said "start your work on it", so I'm assuming it needs work. Do you know the history? Tell us the story about the car, that's what forums are for.

Welcome to the forum! Does it run and drive well?