QuestionI changed the plugs and wires, ck'd for spark for all 4 wires all spark good, listened for fuel pump cks good, not sure on fuel pressure though dont have anything to ck fuel press. the error code was 1 2 4 3 I checked it twice please help thanks in advance!
AnswerHi Ronald,
You didn't mention the year but I'll assume its a '96-7 otherwise it wouldn't give you an error code via the check engine light. For those years, the 43 means a multiple cylinder misfire, which may have been present before you did the tune-up. There are a great many possiblities for that code, so many that you might as well get a manual and run thru the entire list (compression, valve timing, vacuum gauge reading, exhaust back pressure, fuel pressure, spark quality, etc.). But I have a couple of ideas first.
I would check the spark coil resistance values. If you have or can borrow and digital volt-ohm meter, measure between the middle pin of the coil's connector socket and each of the outside pins; it should read 0.45-0.65 ohms. And then measure between the coil towers 1-4 and 2-3 which should be 7,000 to 15,800 ohms. Then you might check the plug side of the coil: Measure for voltage on the incoming center pin of the plug while a helper cranks it. You should get 12v compared to ground (- post of battery) for a crank that last a full 5 seconds. If not, then we may have an issue with the crank sensor, though it should set a code 11. The 12 code is often present though it usually is not an issue. If just means the battery supply to the engine controller has been disconneted recently.
The other item to check is the exhaust gas recirculation valve which is located just below the oil filler cap. It has a body that is attached to the exhaust tube, and then a round top separated from the body by a flange that has openings on either side. Inside the flange opening you will see a rod with a circumferential slot in it. That is the movable valve stem. Try levering the stem using a screwdriver tip to move it back and forth against spring tenision. Check to make sure that the stem comes to a full stop in the direction that the spring is trying to move it. If not, then it may be sticking ajar which will certainly cause a starting problem. If it seems to be sticky, then spray some penetrating solvent on the stem where is enter the valve and move it back and forth some more to free up the movement. Then see if that corrects the no start problem.
Let me know what you observe, please.
Roland
