2004 Jeep Cherokee Cranking Problem

Hi dwebb1911. Welcome to the forum. Real common problem with real easy fix. This is a simple starter problem so don't waste your time in the fuel or other systems. If you have the small silver Nippendenso starter, suspect worn solenoid contacts. They can be replaced for 20 bucks but most people just replace the entire starter. This can happen to any starter solenoid, but it is much more common with the Nippendenso.

Caradiodoc

Did you install a rebuilt or a used starter? A used one will very likely have the same problem because it is so common.

When it doesn't crank the engine, do you hear one kind of loud clunk from the starter each time you turn the ignition switch to "crank"?

Do you have access to a test light and a helper? If so, when it doesn't crank, have the helper hold the ignition switch in the crank position while you test for voltage on the two large terminals on the starter. The one with the large battery cable must have full battery voltage all the time. The terminal under the rubber cap, (and often a little hard to get to), must have battery voltage during cranking. If the second voltage is missing, check for voltage on the smaller wire. If it is there, the solenoid contacts are still the problem.

Caradiodoc

Yup. Your definition of "crank" is the confusing part. "Crank" and "turn over" are the same thing. Both mean the engine is spinning thanks to the starter. Some people take "crank" to mean the engine starts and runs. Some people use "turns over" to mean the engine runs. Think back to the days of hand cranks for starting the engine. Hand cranking turned the engine over so the terms came to mean the same thing.

Based on the symptom, you might suspect the ignition switch or the automatic shutdown relay. The switches have given some problems due to overheated contacts but usually a different circuit is affected. Also, I would expect it to cause stalling problems while driving. The same is true of the ASD relay unless the contact is just sticking. A simple test for that is to switch it with a different identical relay under the hood. The AC compressor relay is a good choice.

Another possible cause is a fuel pump that is not starting up. They almost never stop once they are up and running so they won't cause an intermittent stalling problem, but when they don't start up, the engine will USUALLY run for a couple of seconds on stored fuel pressure before it stalls.

One more thing you might consider is fuel pressure bleeding down over time. The system should hold pressure for many weeks but if it bleeds down, the most common symptom is extended cranking time before the engine starts. It takes a few seconds for sufficient pressure to build up. In some cases, the low fuel pressure causes the initial no-start, and the lower battery voltage due to cranking causes the pump to run too slow to build sufficient pressure. A simple trick to identify this cause is when it doesn't start right away, stop cranking, turn the ignition switch off, wait a few seconds, turn the switch just to "run" but don't crank the engine. Wait a few seconds, turn the switch back off, wait a few seconds, then try to start the engine. By not cranking the engine the fuel pump will get full battery voltage so it will run properly. Every time you turn on the ignition switch, the pump will run for one second, then turn off. That is the reason you have to turn the ignition switch off and back on multiple times to get the pump to run long enough to build pressure.

If that trick helps the engine start right away, dropping fuel pressure can be verified by connecting a mechanical fuel pressure gauge and watching what happens over time. The most common cause of dropping pressure is a leaking fuel injector but a leaking pressure regulator or a leaking check valve in the pump can cause this too.

Caradiodoc