NikoBellick

1997 XJ with AW4 non 4x4 225K on odometer but p.o supposedly bought it as a roller and put a motor and trans in from lkq or some such place.


About a month and a half ago while at a red light trouble shooting a trans problem I went from Neutral to Drive and it died, put it in park and cranked right up. Pulled over and noticed nothing amiss so I headed home. The next day I left for my honeymoon, it sat for 2 weeks but cranked right up no issue when I got back. Took it for a quick drive to Whataburger and while waiting in line I put it in park and turned it off. It took 2 tries to start it again. Drove about 3-5 miles to the house and when going over a parking hump it just died. No idiot lights, cel or any kind of noise or warning just coasted to a stop.

No spark, doesn't start with starting fluid. Tested crank sensor which was good but replaced anyways. Ignition coil within spec but replaced anyways. Still not getting any spark, I can hear the fuel pump kick on when the key is put to on position. Next I'm thinking look under the distributor cap and see if its all burnt up/ replace the cam sensor. Also have heard the auto shutoff relay may be the culprit. All fluids are where they should be, no leaks etc btw.

ANY input is appreciated. Thanks.

t.mcginley.jr

Really sounds like a neutral safety switch problem, located on the dipstick side of the trans. Any error codes/check engine light on? Sometimes the computer can have a pending code and not turn the CEL on.

NikoBellick

No codes or light indication of any kind. I tried starting it while jiggling the shifter in park and in neutral and it wouldn't start. I will however look up the testing procedures and take a multimeter too it.

NikoBellick

I'm also hearing it could be the Automatic shut off relay or some such relay. Should I try jumping the relay to see if that is the problem?

NM-XJ

When you replaced your crank sensor, did you use an OEM unit? There are a few things ya just can't skimp on.

NikoBellick

Yup. Went to oreillys first and bad our of box. Put a dealership one on and still nada. Though I kept it because Im sure it will fail eventually. Hell who knows maybe I put it on again and it works lol.

NikoBellick

Trying to find a diagnostic flow chart for this to give me something to work off of if anyone has a link

SeriousOffroad

Swap the ASD Relay with a known good relay.

XJ607

the asd relay controls power to the fuel pump as well so I wouldn't think it would be that if u can hear the fuel pump and still have a no start, I would try testing the nss like said above but from my experience that's usually when u have no cranking, it cranks over correct?

'90Cherokee

My guess is a loose connection somewhere since shifting will move the engine around as will bumps and the dying out is always related to one of these inputs.

I'd put a test light on the coil power wire, assuming it'll be no power right now, start giggling stuff till it lights and fix that connection or component. Use a light and not a meter, you want some load on the circuit, a meter can lie in a high resistance situation. I don't think the neutral safety switch can kill the engine, it just interrupts the starter power.

NikoBellick

I hear the pump kick on but not for 3-5 seconds I just hear it kick on.

Yes it cranks, starter engages, pulleys turn etc just no spark.

Will Swap the relays around just to rule out the ASD.

Good chance it is a loose wire, the p.o supposedly bought it as a roller and put in a engine and trans. Folks have also been saying a wiring issue may be the cause of my trans issue as well. Thanks for the suggestion, I will get a spark tester and do just that! Clean all my grounds and connectors while I am in there.

Going to pull the cap off tonight and have someone crank it so I can see if the rotor etc is turning.

Any thoughts that it could be the Cam sensor?

ehall

The computer controls spark and injector timing so if you get no-spark you can eliminate a bunch of the computer components by monitoring the injectors. Get a mechanic's stethoscope and listen to the injectors while somebody cranks the motor. If you don't hear any clacking sounds then something on the computer circuit--crank sensor, cam sensor, asd relay, ecm, or wiring. If you do hear the injector firing then the problem is with the ignition system (coil, ground, etc)

NikoBellick

Nice, I like that idea!


Thank you everyone, I'll update y'all as soon as I get time to mess with it which will probably be tomorrow or Sunday. I'm sure it'll be something simple once I get it figured out.

NikoBellick

It was the damn shutdown relay. Either it was labeled wrong or I swapped the wrong two idk but started right up. I've got a new one in there now but I'm wondering did the relay fail or did something cause it to fail. I'm guessing it just failed but I'll still do some general maintenance this weekend and see if anything else is amiss.

Now, if I could figure out if I need a new trans or have a wiring issue I'd be ecstatic.

NikoBellick

Ok, so new shutdown relay seems to be the trick, runs fine and starts every time so far. Now, while letting it idle and warm up I started jiggling wires and looking things over. I started tapping lightly on the relays and noticed when tapping near the Asd the motor would stumble and when tapping a couple times on the relay itself I noticed it seemed to jiggle abit and after a few taps the motor died. Noticed the relay was warmer than the rest. Motor starts right back up.

With that said, I'm wondering was it/is it just a loose relay that was my problem or was the relay doing its job and shutting down for a reason it was intended to and I have a problem I'm not seeing?..