xj won't start!!!!!!!!!

[cc chasse]

I came home with my 2000 XJ running fine. went out in the morning and it turns over but won't start and the fuel gauge reads empty.
I know I have gas in the tank but I added some just incase someone stole it. I thought it might be the fuel pump since I can't hear it running when I turn the key on so I swaped the relay to see if it was bad still nothing. I removed the relay and jumpered it and the pump runs. But It still won't start. It doesn't apear to be getting spark. I'm thinking computer but don't have a scanner to confirm. Does anyone have any suggestions.

[langer1]

Whats the speedo say? If there was a comp problem it would say "No Buss"
You have a bad fuse in the PDC.

[Jess]

check the engine control fuse...one my 95 the NSS shorted out and blew the engine control fuse and showed the same symptoms (no fuel pump power and it would turn over but not start)

[cc chasse]

I checked all fuses in the psc with a meter and didn't find any that were bad. I did find a 25 amp fuse that was bad in the kick panel fuse block. I not sure what it was for but I replaced it and it didn't blow again. but it didn't resolve the issue. still looking

[cc chasse]

What's NSS? and which fuse is engine control? my manual sucks!

[Saudade]

The NSS is your Neutral Safety Switch. If you have an auto, try shifting into neutral and see if it starts.

You might also check your Cranshaft Position Sensor (CPS). You can search the forum and finds lots of stuff on it.

[langer1]

The NSS would not allow it to turn over, but op says in cranks but no start.
No fuel punp can also be a bad ASD relay

[cc chasse]

NSS shifted to neutral tried to start , still no luck. Planning to test tomorrow with Computer testing.

[Saudade]

The NSS would not allow it to turn over, but op says in cranks but no start.

Whoops, musta missed that in his original post.

[cc chasse]

IMy wife said she thinks it did say no buss on the speedo. Is that an easy repair? Remember my manual sucks!

[langer1]

IMy wife said she thinks it did say no buss on the speedo. Is that an easy repair? Remember my manual sucks!
Could be still check the fuses.

[cc chasse]

In thinking about it the no bus happened when I unplugged the plug at the fuel tank. I've now checked all the fuses and not found any more blown. Things are starting to look grim. Does anyone know what the relays located behind the kick panel next to the fuse block are?

[langer1]

In thinking about it the no bus happened when I unplugged the plug at the fuel tank. I've now checked all the fuses and not found any more blown. Things are starting to look grim. Does anyone know what the relays located behind the kick panel next to the fuse block are?

Things like flasher, Headlight timer, washer timer.
You are testing the fuses under the hood right?

[cc chasse]

Yes, I removed and inspected and tested all fuses in the PDC with a test light. I'm a little confused would a bad CPS stop the fuel pump and spark.

[Saudade]

Yes. Does your pump run now for a few seconds when you first turn on the key?

[langer1]

Yes, I removed and inspected and tested all fuses in the PDC with a test light. I'm a little confused would a bad CPS stop the fuel pump and spark.

I would say spark yes fuel pump no, it would also not cause a "No Buss" swap the relays around and see if the ECU fires up. The no buss means the ECU is not running it can be the ASD relay until you get the ECU running not much else will work either, you can't even get codes.
It's very unusually that a ECU fails to the point it don't even run
One other thing, before the ECU turns on it does a self test, if a short on one if the outputs wires is detected it don't start to protect the ECU, so check the wires around the exaust header for burns or shorts.

[cc chasse]

John,
I hooked up the reader and did not even get any code! Is there a way to test the ASD relay none of the other ones seem to be the same size to swap. Thanks for the advice I was calling the boneyards looking for a computer.

[langer1]

The computer will need to be dealer installed, it must be re-programed to match your vin code and Odometer.
A bad computer will throw a bad computer code "don't know the number", a computer that has no power won't throw any codes.

[Rocketman]

Did ANYONE tell this guy to check the CPS??

Crankshaft position sensor, on the exhaust side of the bell housing with a wire that runs up to a connector near the back of the intake manifold.

[langer1]

Did ANYONE tell this guy to check the CPS??

Crankshaft position sensor, on the exhaust side of the bell housing with a wire that runs up to a connector near the back of the intake manifold.

He was told to look there for a short but a bad CPS will not cause a NO BUSS fault

[Gunner]

This XJ is much much newer than mine. I had the same problem twice. My computer took a dive both times. I regrouded everything I could find the last time. And haven't had the problem since. The computer was burned both times in the heat sink. But mines a Renix... So it was plug and play for me.

[cc chasse]

I'm going to get a relay in the morning and keep my fingers crossed. I'll also check the CPS.

[Gunner]

As funny as it may sound I had problems in the past and went striaght to the CPS... I now have like 5 spares cause it was never the problem. Had a buddy with a 99 and everytime his tank got half empty or lower he blew a fuel pump relay. And I mean everytime. The relay might be the culprit. What causes it has never been figured out. Good luck .

[cc chasse]

I changed the ADS relay, It's not that! On to the CPS Is their a way to test if it's working with a multi-meter?

[langer1]

Because your ECU is dead you could just unplug the CPS and see if your ECU comes back to life and gives a code.

Did you check for burnt wires going to the o2 and CPS?

[cc chasse]

I'm looking at the wires and not finding any damage. I gave my buddy back the scanner last night since it didn't find any readings. Is there another way to test? all I have right now is a multi-meter and a test light.
I hate electrical problems! Sometimes I wish we could go back to simpler times oh how I miss points and carbarators.

[cc chasse]

I just unpluged the CPS and for grins I reconnected the battery and heard the fuel pump cycle.
It this a good sign that I'm heading in the right direction?
The CPS is a real mother to get at this is another example why engineers should have to spend some time actually working on what they design.

[langer1]

I just unplugged the CPS and for grins I reconnected the battery and heard the fuel pump cycle.
It this a good sign that I'm heading in the right direction?
The CPS is a real mother to get at this is another example why engineers should have to spend some time actually working on what they design.

Is your dash still saying "No Buss" thats important.

I have to keep harping but the wires ofter short out going down to the o2 sensors or the CPS so you still my have a bare wire.

[cc chasse]

No more no bus. All the wires are in their original sheath and I don't see any damage to it but it's very difficult to trace because of doing it on my back and where it is.
Now that I've removed the CPS where do I get one on a Holiday Weekend:tears:? Is it an Dealer Item or would an Autoparts Store (IE NAPA) stock it?

[langer1]

Yes local parts store.

[langer1]

You should normally get a po344 code when you have a bad CPS but a shorted one or again the wire to the CPS shorted will cause the ECU to shut down (no Buss).

[cc chasse]

Ikeep looking at the wire for shorts but am not finding anything! It's driving me mad..... I'll try a new CPS in the morning if I can find one!

[langer1]

Autozone should be open, your on the right track though.

[cc chasse]

I just installed the CPS and it runs now!party1: Thanks for all the help. Without it I wouldn't have ever found this problem on my own. I was almost ready to have it towed to the dealer. I miss the day of CJ's that were made for the owner to work on.