My 1989 4cyl starts but then immediately stops. Checked spark to plugs and noticed I have spark so long as ignition switch kept in "start" position (and the engine actually runs on its own) but when switch moves back to "run" position the spark disappears and engine stops. Help!

Probably either a fuel or a spark problem. You need to check for the presence of a good spark immediately the engine stops - by using a spark gap, a spare spark plug or a propriety spark indicator.

If the spark is found to be absent the fault is likely the ignition module but check all connections and the stop switch operation before replacing.

If the spark is present then the fault is probably fuel-related and is the sort of thing a tiny droplet of water in the carb could cause...

There are many things that can cause the vehicle to stall/not start. The 2 most common are lack of fuel and lack of spark. Possible fuel pump issue or relay/wiring to fuel pump. This can be checked/ruled out by performing a fuel pressure test. Another common issue with this vehicle for stalling/no start is a crankshaft position sensor that will cause an ignition spark failure. Have the codes scanned as this sensor will usually set/store a code before you throw any more parts at it

The motor turning over & cranking---- is one in the same

You have a :
NO CRANK or a NO START !!!

You checked fuel pressure at the motor
You checked for spark or injector pulse
The battery is good-you tested it

Now tell use about the loss of ignition output

Where is all that coming from--in detail

Have to crank sensor scoped

Is the ignition switch worn out ?

the code p 0302 refers to no 2 cylinder misfiring===causes --engine mechanical fault ---wiring--ignition / fuel system---injector--ECT/Maf sensor ---ECM
you state that the engine runs normally for several seconds so I would eliminate a mechanical fault at this stage
most misfires are from faulty injectors so reposition the injector to another cylinder and see if the miss moves along as well
if it doesn't move but stays at no 2 cylinder , then it could be a problem ECM
if you can get a substitute ECM of known good performance , swap it out and see if that fixes the fault

It sounds like your security system is the culprit.The computer does'nt reconize the code on your ignition key and it thinks some is triying to steal it so the computer shuts the injectors off.You will probably have to replace the ignition switch and the ignition lock cylinder.

It can be the problem with ignition cylinder or faulty ignition switch causing this problem.But if you notice no start problem on your car,then there are many other possibilities too. No start problem.This is many a times caused by weak battery or faulty battery, or can be possible that battery to starter connection is loose or faulty starter itself.First the battery to start and both battery and starter voltage needs to be checked and confirmed.If that is checked ok, then other possibilities like faulty spark plugs, faulty fuel pump etc etc needs to be checked. For more detailed troubleshooting,click the link below:--- http://howtobyme.blogspot.com/2011/10/car-troubleshooting-tips.html ---------- This should help.Thanks.Helpmech.

sounds like your ignition switch may be faulty.

When the car stops driving, at that time check the starter, if its got very hot, then this can be starter over heating issue. There are many other things to be checked.

Try this troubleshooting: ----If your engine cranks normally but will not start because it has no spark, or it stalls and won't restart because it has no spark, the problem may be due to any of the following:

1) A bad pickup inside the distributor, a stripped distributor drive gear (common problem with plastic distributor drive gears), broken, loose or corroded wires from the pickup to the ignition module or PCM. 2) A bad crankshaft position (CKP) sensor or broken, loose or corroded wires from the sensor to the PCM. 3) A bad ignition module or A bad ignition coil .

4) A bad rotor or distributor cap (cracks or carbon tracks that are allowing the spark to short to ground). 5) Faulty ignition switch.

------------

You can also do a test to confirm the problem .The procedure to do the test is as follows: --

If your engine has spark plug wires, disconnect one of the plug wires from a spark plug and place the end of the wire near a metal surface on the engine. Then insert a small Phillips screwdriver into the end of the wire (the plug boot), or a small bolt or nail to provide a conductive path. Then crank the engine and look for a spark to jump from the screwdriver, bolt or nail in the end of the plug wire to the engine. If you do not see a spark, there is an ignition problem.

OR---If your engine has a coil-on-plug ignition system with no plug wires, In that case remove one of the coils from the spark plug and insert an old spark plug, a spark plug tester or a screwdriver into the end of the coil. Ground the spark plug or plug tester to the engine, then crank the engine and look for a spark. No spark indicates an ignition problem. Possibilities to be checked in this problem are as follows:-- If the engine has no spark, check for voltage at the coil positive terminal when the ignition key is on. If NO voltage, then problem is on the trigger side of the coil (pickup, crank sensor, ignition module or primary wiring circuit).But If there is NO voltage at the coil itself, then in that case the problem is on the supply side (the ignition switch or ignition wiring circuit). But if the coil has voltage, then problem may be a bad high voltage output wire from the coil to the distributor, hairline cracks in the coil output tower, or cracks or carbon tracks inside the distributor cap or on the rotor. ------A car that cranks over but doesn't start, in many cases will be due to a bad fuel pump, a broken timing belt, an inoperative cam sensor or crank sensor. Also these problems are related to faulty spark plug. Check the spark at spark plugs when you start the car. Do you notice any spark. Actually you should see. If in case there is no spark then it's a spark plug problem. Also the coil pack gives power to spark plug. So check the voltage at coil pack. It will show 12 volt. If there is no voltage noticed at coil pack then its faulty coil pack that has to be replaced. If all the possible options checked out ok then check the car starter. The starter gets power from battery to start the car. If the starter is faulty then it will not let the car to start. Also check and confirm that there is fuel in the car. If its very low fuel then in some cases this causes the problem. Also check and confirm that fuel pump is functioning properly and the fuel filter is not clogged. One of the easiest ways to check for a fuel pump related problem is to spray a little starting fluid into the air intake while trying to start the car. If the car starts momentarily, then there's a good chance the fuel pump is not working or the car is out of gas. You can also listen for the fuel pump's humming sound when the key is first turned on. Also if a inoperative fuel pump is suspected, a good technician will always check to verify there is power and ground being supplied to the pump, to eliminate the possibility of a bad relay or electrical issue. Fuel pressure can be checked with a pressure gauge and if there is pressure, pulse can be checked at the fuel injectors in several ways including the most common, with the use of noid lights. If the injectors don't have pulse the engine won't start.---------- This troubleshooting tips will help you to solve the problem. Thanks. Helpmech.

Yes it is very much possible.But there are many other possibilities too,including starter and spark plugs issue.

If your engine cranks normally but will not start because it has no spark, or it stalls and won't restart because it has no spark.

You can also do a test to confirm the problem .The procedure to do the test is as follows:---

If your engine has spark plug wires, disconnect one of the plug wires from a spark plug and place the end of the wire near a metal surface on the engine. Then insert a small Phillips screwdriver into the end of the wire (the plug boot), or a small bolt or nail to provide a conductive path. Then crank the engine and look for a spark to jump from the screwdriver, bolt or nail in the end of the plug wire to the engine. If you do not see a spark, there is an ignition problem.

OR-----------

If your engine has a coil-on-plug ignition system with no plug wires, In that case remove one of the coils from the spark plug and insert an old spark plug, a spark plug tester or a screwdriver into the end of the coil. Ground the spark plug or plug tester to the engine, then crank the engine and look for a spark. No spark indicates an ignition problem.If the engine has no spark, check for voltage at the coil positive terminal when the ignition key is on. If NO voltage, then problem is on the trigger side of the coil (pickup, crank sensor, ignition module or primary wiring circuit).

But If there is NO voltage at the coil itself, then in that case the problem is on the supply side (the ignition switch or ignition wiring circuit).-----------------

Jeep cranks but no start:----------------

A jeep that cranks over but doesn't start, in many cases will be due to a bad fuel pump, a broken timing belt, an inoperative cam sensor or crank sensor. Also these problems are related to faulty spark plug. Check the spark at spark plugs when you start the jeep. Do you notice any spark. Actually you should see. If in case there is no spark then it's a spark plug problem. Also the coil pack gives power to spark plug. So check the voltage at coil pack. It will show 12 volt. If there is no voltage noticed at coil pack then its faulty coil pack that has to be replaced. If all the possible options checked out ok then check the car starter. The starter gets power from battery to start the jeep. If the starter is faulty then it will not let the car to start. Also check and confirm that there is fuel in the jeep. If its very low fuel then in some cases this causes the problem. Also check and confirm that fuel pump is functioning properly and the fuel filter is not clogged. One of the easiest ways to check for a fuel pump related problem is to spray a little starting fluid into the air intake while trying to start the jeep. If the car starts momentarily, then there's a good chance the fuel pump is not working or the jeep is out of gas. You can also listen for the fuel pump's humming sound when the key is first turned on. Also if a inoperative fuel pump is suspected, a good technician will always check to verify there is power and ground being supplied to the pump, to eliminate the possibility of a bad relay or electrical issue. Fuel pressure can be checked with a pressure gauge and if there is pressure, pulse can be checked at the fuel injectors in several ways including the most common, with the use of noid lights. If the injectors don't have pulse the engine won't start. ---------- This troubleshooting tips will help you to solve the problem. Thanks. Helpmech.

If coil is good and plugs are not - there's your problem. You can't have output of coil be good and plugs not work right. Something inbetween is wrong.