No start, no crank

[Norton]

Gentlemen.

I have a manual 89 2.5 TBI MJ w/ an AX4

 

Out of nowhere the jeep suddenly won’t crank at all. I have power to all accessories and it even randomly started once out of 50 tries when my girlfriend turned the key of course but otherwise the only sound is one click and a whirring/humming noise.

 

So far I’ve replaced my starter and checked/cleaned most electrical connections I could find, including the CPS.

It bump starts fine too.

 

What else should I be considering?

Any help is appreciated

 

 

 

[eaglescout526]

How’s the battery and its cables? Grounds cleaned? Usually if you can’t get it to crank at all, it’s usually due to a dead battery or corroded connection. Doesn’t take much for the little 2.5’s to not crank and start. 

[ghetdjc320]

Sounds also like possible starter solenoid. But try another good battery first. 

[GonzoTheGreat]

The whirring sound makes it seem like the starter is spinning, but not engaging the flywheel. Did this noise happen with the old starter as well? Or only once the new starter was installed?
 

A difference between 4.0s and 2.5s is that the 2.5 uses shims under the starter motor.

 

Did you have any shims under the old one? I had to adjust the shim pack on my 2.5 when I replaced the starter.
 

again though, this is assuming the whirring noise accompanied the new starter.

[Eagle_SX4]

If the "new" starter you put in was rebuilt it is probably to blame. I have had issues with rebuilt starters from the parts stores. I put 3 into my Eagle before I got a good one. Ask the clerk at the counter to bench test it before you walk out the door.

[Norton]

1 hour ago, GonzoTheGreat said:

The whirring sound makes it seem like the starter is spinning, but not engaging the flywheel. Did this noise happen with the old starter as well? Or only once the new starter was installed?
 

A difference between 4.0s and 2.5s is that the 2.5 uses shims under the starter motor.

 

Did you have any shims under the old one? I had to adjust the shim pack on my 2.5 when I replaced the starter.
 

again though, this is assuming the whirring noise accompanied the new starter.

Yeah I’m inclined to think that the starter is spinning but just not cranking hard enough too. I never saw or replaced any shims. Not sure if it made that sound with the old starter, couldn’t hear much over the engine turning over.
Replaced the starter like 6 months ago after it went out the first time and it worked right away. Thought it was the same issue this time around but just replaced the starter again and nothing.

 

Any thoughts on starter relay? If it had gone bad the starter wouldn’t whirr at all correct?

[eaglescout526]

Correct. The starter relay wouldn’t do much of anything. Would provide power everywhere else as it’s the hub of all the electrical on the Jeep. That being said it also sends a crank signal to the ECU and power to the fuel pump. It also has ground there as well that goes to the dipstick tube which grounds out at the firewall and by the alternator on the block to the battery. 

Id definitely check the battery cables to and from the battery and to the starter relay to make sure there’s no corrosion at all. These things don’t like any sort of resistance what so ever as I stated in my first reply. 

[Norton]

31 minutes ago, eaglescout526 said:

Correct. The starter relay wouldn’t do much of anything. Would provide power everywhere else as it’s the hub of all the electrical on the Jeep. That being said it also sends a crank signal to the ECU and power to the fuel pump. It also has ground there as well that goes to the dipstick tube which grounds out at the firewall and by the alternator on the block to the battery. 

Id definitely check the battery cables to and from the battery and to the starter relay to make sure there’s no corrosion at all. These things don’t like any sort of resistance what so ever as I stated in my first reply. 

The starter relay is the white thing with the brass bracket along the steering column correct?

[eaglescout526]

11 minutes ago, Norton said:

The starter relay is the white thing with the brass bracket along the steering column correct?

Nooo. That’s the ignition switch. 
starter relay is under the hood, by the battery and two or 3 or 4 relays under a black cover(if you still have that cover). Typically there’s 2 relays. Fuel pump and B+ for the O2 heater. Other two would be AC and fog lamps. 
 

Starter relay has a big mess of wires on it. 

[eaglescout526]

 

This is the black cover. Where I’m pointing is the general area of where the starter relay is. 

[Norton]

Found the relay and corresponding grounds and gave em a clean. Nothing new still.

Tomorrow is my day off and I will making as many trips to the parts place as it takes. 
Thanks for all the input and will keep everyone updated

[eaglescout526]

I’d give the end that goes from the battery to the relay a good clean too along with the other eyelets bolted to the relay. Do let us know if anything changes. 
Hmmm, I’d almost test the ignition input from the ignition switch to the relay. 

[Norton]

So… checked voltage all the way to the starter. 12v all the way thru. Bench tested the starter I took out and it worked well so I reinstalled it as the newer one I had just installed looked sketchy anyways. New mounting bolts, good clean on solenoid connectors and terminals/grounds ( + everything else electrical) and she starts. Thanks everybody.

 

In other news, does anyone know where to get their hands on a new distributor cap/rotor for a 2.5? Can only find them for 4.0’s online.

[GonzoTheGreat]

Rockauto has quite a few.