Help!!! I can't figure it out. Need to get my XJ started! What could be wrong??

We pulled into get gas at Racetrac... Jeep running great.
Pumped $5 into the tank.
Went to start it.... It spit and sputtered... quit.
I did not touch the throttle at all.

Kept trying to start it for a half hour. Wouldn't start.
Tried starting it holding down the gas. Same thing... cranked... nothing.
Ran down the battery.

After 2 hours, finally got a jump... from a good old country boy in a barely running old Chevy truck.
We tried everything. Cranked fast but wouldn't even fire. Sprayed Either down the throttle body, Checked wires. Everything looked normal. Nothing worked. It just will not fire.

He offered to tow it home.
Got it home finally.

I do not have an ODB II tester to check codes.

What could be wrong? Please, help. Need the XJ bad as it is our only vehicle.

Thanks.

The engine has been modified.

8.5 wires
accel coil
exhaust header
Cold air induction K&N cone
new distributor cap and rotor
New plugs

new crank case sensor
new MAP

All done in the last 6 months.

Need to know year, motor, ignition (Renix?) but first need to check-
Do you have spark?
Do you have fuel pressure?
Are the injectors firing? Need noid lights for that (10 bucks or so at NAPA I think)
What you list as mods probably doesn't really count as modified (more like replacing worn out parts) but regardless you're posted here for now. It may get moved to the OEM forum. Once you have figured out whether you have spark or not, or fuel or not, you can start following the respective rabbit trail. If no spark, do a search on the OEM forum for "no spark" or similar. Same for no fuel pressure or injectors not firing. Sorry couldn't be of more help.

I'm sorry. I am mistaken. What would constitute a Mod?
I am building this XJ for my son (16) I am his mom.

We have a '96 XJ Country 4x4 4.0
Lifted, etc., etc.

We have been watching this site for a few years to get ideas but hardly posted.

Thanks for your help. It is appreciated.

I was thinking it might be the ECU or Ignition Control Box

I really do not know how to check all those things
I can do spark.
Fuel pressure and Injectors... I have no idea.

check spark,

when you turn it over you should be able to smell the gas if its not firing, if you are getting gas.

Start there, post back

Classic failed crankshaft position sensor,
No start and no spark.

$60-$100 part. 2 bolts and a connector. I pulled mine reaching down into the driver's side of the engine bay with a 7/16 wrench. Most do the job from underneath with extensions and a swivel joint.

cher96 said:

The engine has been modified.

8.5 wires
accel coil
exhaust header
Cold air induction K&N cone
new distributor cap and rotor
New plugs

new crank case sensor
new MAP

All done in the last 6 months.

Click to expand...

I forgot to mention:
Remote Oil Filter and Oil Cooler
Transmission Cooler
62mm TB and TB Spacer
2.5 CatBack Exhaust
3 Core All Metal Radiator
Hi Flow Water Pump, Thermostat Housing, and Thermostat

Not to mention all the Suspension Modifications

The only thing that has not been "Modified" is the inside of my 4.0. It burns no oil and I have used only Royal Purple Synthetic Products. It usually runs perfect at 160,000 miles.
This weekend 2004 Intake Manifold installation.

I see many new people post in this category, Modified Tech Discussion, that have done a lot less with their XJs or are just starting out on their modifications.

I only posted those things I thought might be pertinent to my present problem.

I had gotten the Jeep started the next day only after jumping it and spaying a massive amount of Either into the intake.

Before I started it, I did check for spark and there was plenty of it.

After starting it... I ran around for a week without any problem at all.

Then, I went to get gas again, same problem. Even with Either I could not get it started at the gas station. The next morning we jumped it and sprayed Either into the intake and it started again. Again I have gone all week without a problem. However, I am afraid to get gas again and my tank is near empty.

Can anyone help me out?
Anyone have this problem before?
How did you solve it?
Any ideas?

Thank you.

Is a Crankshaft Position Sensor a different part than a Crank Case Sensor?

I had it in a shop 6 months ago for what the mechanic called a Crank Case Sensor. It was at the top of the Bellhousing in back of the Engine.

What do I know... he may have said,"Crankshaft Position Sensor." Is that where it would be?

Thanks.

the crankshaft position sensor is the one on top of the bellhousing, it commonly causes no start conditions.... if it was recently replaced, make sure its plugged in, and the wire is not melted....

you say you dont know how to check for fuel..... as far as BASIC troubleshooting... theres a schraeder valve on the front of the fuel rail, under an aluminum cap.., turn the ignition to 'on', to prime the fuel pump (can you hear it prime?) then goto the engine bay, and depress the valve... like letting air out of a tire... you should get a healthy squirt of fuel... (40~ish psi) NOT A DRIBBLE...

if its a dribble, or nothing, you obviously aint got no fuel, so check the fuel pump 1relay, ballast resister, and fuel filter (for clogging).

sorry about your troubles, my xj isnt running right now either...

xcm said:

the crankshaft position sensor is the one on top of the bellhousing, it commonly causes no start conditions.... if it was recently replaced, make sure its plugged in, and the wire is not melted....

you say you dont know how to check for fuel..... as far as BASIC troubleshooting... theres a schraeder valve on the front of the fuel rail, under an aluminum cap.., turn the ignition to 'on', to prime the fuel pump (can you hear it prime?) then goto the engine bay, and depress the valve... like letting air out of a tire... you should get a healthy squirt of fuel... (40~ish psi) NOT A DRIBBLE...

if its a dribble, or nothing, you obviously aint got no fuel, so check the fuel pump 1relay, ballast resister, and fuel filter (for clogging).

sorry about your troubles, my xj isnt running right now either...

Click to expand...

He has hit it on the head there. Had the same prob in my aunts jeep ended up being the feul pump. Check the other things first though I always start with the cheaper and work my way to the high amount parts.
Sounds like that was your crankshaft position sensor that they replaced for you, had one go out on my rig once they are good for that.

I never had anything newer than an 87 vehicle before my 96 XJ so all this computer and electrical stuff is new to me. I am learning ever so slowly and appreciate your help.

Before I get gas in the morning, I will check out the Schraeder Valve to see if I have a healthy amount of fuel coming out. If it is not pumping, I will replace the relay, then the ballast resister and fuel filter, hopefully it will be done.

I priced out the parts for replacing a fuel pump and it came to $170.00 without shipping and I do not think it is a easy thing to replace.

Thanks again for all your help.
Vicki

The goal is to figure out what is wrong by testing. Please don't just start replacing parts. Testing the fuel pressure is good. You can borrow a tester at the auto parts store and hook it up just like a tire pressure gage. The fuel filter is attached to the pump inside the tank, which I am pretty sure would need to be dropped out of the vehicle to get to. I don't think yours has the (white ceramic) ballast resistor. If it does, you don't need it anyway and can just wire around it.

Does it start good, even on hot restart, except when you gas up? Have you tried gassing up when it's only half empty? Have you tried not filling it up all the way? Your symptoms are strange, but your ballast resistor and fuel pump relay cannot be affected by the refilling of fuel.

winterbeater said:

The goal is to figure out what is wrong by testing. Please don't just start replacing parts. Testing the fuel pressure is good. You can borrow a tester at the auto parts store and hook it up just like a tire pressure gage. The fuel filter is attached to the pump inside the tank, which I am pretty sure would need to be dropped out of the vehicle to get to. I don't think yours has the (white ceramic) ballast resistor. If it does, you don't need it anyway and can just wire around it.

Does it start good, even on hot restart, except when you gas up? Have you tried gassing up when it's only half empty? Have you tried not filling it up all the way? Your symptoms are strange, but your ballast resistor and fuel pump relay cannot be affected by the refilling of fuel.

Click to expand...

It only has happened after getting gas. It has happened twice. Then, the same problem after pumping gas into it.

1st time I only put $5.00 into a quarter tank.
2nd time I filled it up, $30.00 on an eighth of a tank.

After running down the battery trying to start it, I had to leave it over night until I could work on it. The next day, jump it, spray Either into it, after a while it starts up and has no problem starting until I put gas into it a week later.

It runs perfect all week, no problems. Whether hot or cold, never a problem. Only after pumping gas into it.

Now, I must buy gas again and I am afraid to do so.

Thanks to all of you trying to help me.
Vicki

Do you ven here the pump humm for e sec when you turn the key on?

I have tried to listen for the fuel pump. It is extremely noisy in my neighborhood. I am between two major avenues and next to the freeway. Often I have to speak loudly for my children to hear me.

In other words, I have never heard the fuel pump, even when trying to listen closely. I have tried many times before starting my XJ. But then again, I would have no problem starting it unless I pump gas into it.

Thanks.

Only after you pump gas into it... ? Of course there is a sensor on the pump that does fuel level. But I dont think that would do it. It cant be bad gas if you get it started and runs fine.

Sorry just thinking here... I have a 93 witch is pretty similar. Ive had weard stuff like this happen to me to. But it always ends up being the computer. Im not saying it is, but it could be. I just go to a junk yard and get it for cheap, sounds bad I know but im cheap anyway.

Now when it would start for you, did it all of a sudden start one day or do you remember doing something to make it start.

After pumping gas into it... it would only start up the next day when jumping it and spraying Either into the intake.

Any other time... it always starts right up and runs great.

Theres gotta be no fuel pumping to it then. If you have to spray somthing into it to start it, then its not getting gas. I think its safe to say the pump is bad, or has a bad wire going to it, or its not getting told to pump.

On the fuel rail, there is a purg valve in the middle. Does gas kinda spert out after turning the key on. It like a tire air valve.