97 TJ crank no start

[1997TJwrangler]

Hi all,
Hoping for some advice to get this thing going again.

Currently no start ( but cranks)

Previously sounded like the fuel pump stayed on longer than it should in starup. Took a long time to start, multiple ignition cycles.
Once running had no problems at all.
I've changed out plugs, leads, crank position sensor, cam sensor, new battery. Checked and cleaned ground.

Now I get no lights at all on dash when I turn the key, no fuel pump noise. (Lights work, radio comes on)
Plugged computer into another similar jeep, it got all the lights up etc.

Checked the wiring loom as best I can, seems ok.

Chasing some suggestion on where to from here?
Ignition switch maybe?

Thanks in advance

 

[macleanflood]

What's your fuel pressure?

Try a inline spark plug tester or pull a plug and check for spark.

-Mac

 

[Mac57]

Previously you were experiencing multiple cranks and long fuel pump runs before it would start and then run fine. Now you have no fuel pump running sounds at all. Looks like a fuel delivery issue, possibly a failed pump. As macleanflood suggested above check your fuel pressure. Should be somewhere in the high 40's PSI. However, before doing so ensure you have a fully charged battery. I know you said you have a new battery. New doesn't always mean fully charged or not defective. It doesn't take much of a voltage drop to cause no start issues.

 

[Cooper Smith]

Hi all,
Hoping for some advice to get this thing going again.

Currently no start ( but cranks)

Previously sounded like the fuel pump stayed on longer than it should in starup. Took a long time to start, multiple ignition cycles.
Once running had no problems at all.
I've changed out plugs, leads, crank position sensor, cam sensor, new battery. Checked and cleaned ground.

Now I get no lights at all on dash when I turn the key, no fuel pump noise. (Lights work, radio comes on)
Plugged computer into another similar jeep, it got all the lights up etc.

Checked the wiring loom as best I can, seems ok.

Chasing some suggestion on where to from here?
Ignition switch maybe?

Thanks in advance

Can you jump the fuel pump relay pins to get it to kick on? Relays do wear out over time, especially after 28 years.

 

[hairyibis]

If you end up having fuel pressure and no spark take a look at your ignition coil, mine failed on my 97 recently.

 

[ckfaile]

What about no power to the coil?

 

[ckfaile]

Why would there be no power to the coil?

 

[hear]

Why would there be no power to the coil?

Because the computer cut power to the ASD relay, most likely. WHY it did that is another story.

 

[1997TJwrangler]

Thanks for your replies.
I've narrowed it down a bit more - removed aftermarket immobiliser.
Symptoms are now:

1st key turn to on - takes about 30 seconds for fuel pump to turn on, then it doesn't turn off.

2nd key turn fuel pump comes on straight away and doesn't turn off.

No fuel or battery gauge movement, all other lights and alarms come on.

No spark.

I think I'm down to replacing PCM?

Any other ideas??

Thanks

 

[macleanflood]

Tell us more about removing this aftermarket immobilizer?

Sounds like wiring issues to me.

-Mac

 

[1997TJwrangler]

Hi Mac,
Immobiliser and central locking was wired into the steering column (not at vehicle but I think it was a blue wire). I have removed all of this wiring so now back to original as best I can tell.

I didn't receive a button key with the car, so assume this may have been out of order for sometime.

Cheers

 

[macleanflood]

The wiring diagrams are in the Factory Service Manuals located in the resources section. 8w. Might want to take a look and at least visually verify things.

Do you have a code reader or Bluetooth ODB dongle and can you communicate with the PCM?

-Mac

 

[DeathTrap97]

Any updates on this? I'm having the exact same issue. Thinking of replacing the ignition switch. I've removed all of the fuses and relays to try and recreate the problem but none of those seem to recreate the original issue the same way... Just wondering if the ignition switch could cause these issues...