Engine wont start

If inertia switch is OK then inspect fuel pump driver module.

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Can you check fuel pressure? If you think it is a fuel issue, check the bump switch. The owners manual says it is in the trunk on the left side, behind the trunk lining.

If that is a two wire connector, back probe the circuits with the engine cranking, both wires should be hot. Let us know what you find.

Were you using a scanner or code reader?

You could try reseting the bump switch. Also, I thought that might be the easiest place to start checking for voltage at the rear. Have a helper crank the engine.

If this vehicle has electronic returnless fuel system, there should be a fuel pressure PID on the scanner.

I wouldn't replace anything, without checking fuel pressure. I asked about that in the first post. My hearing is no good, I can't listen for the pump. I have to check fuel pressure and amp draw for the pump.

I just wanted to add, the voltage and ground for the fuel pump motor comes through the pump driver module. You have to have both voltage and ground or the pump motor won't run. I believe the ground is a duty cycle, switched on and off. If there is something wrong with the system, a code should have set. Whether it will or not is a different story.

Pick your symptoms and get back with some testing results

Cranks but no start condition:

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.

If both fuel and spark is present-check the valve and ignition timing, this will lead you to problems
with compression and valves opening and closing at the wrong time/broken or jumped timing
belt/chain.

No crank at all/nothing/nada:

Could be the starter, starter relay, park and neutral switch/clutch switch and ignition switch assuming the battery and connections are good

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.

Say it won't turn over

Let rule out "seized up"

"key off"

See if you can rotate the engine with a wrench--one full revolution (or more). Put a mark on your harmonic balancer so you will know when you get there

I demonstrate in pic, with my jeep cj 5 engine

The medic

Need your info

How 'bout checking your battery voltage w/ a digital voltmeter

The gauge itself is not killing the vehicle

Voltage is a big question here---if it's low, do not jump it off----remove it and recharge the battery out of the vehicle---or replace it w/ a fully charged one

This may also reset your computer (still glitching 'cause battery has not been disconnected) a fully charged one will reset it---then have battery and charging system tested immediately, most auto parts stores will load test and fully test the system for free.

Keep us informed

The medic