RandsGear

I have a 2000 XJ SSP 4.0 with a no start issue.


I’m a jeep greenhorn. Had this one about 2 years and am learning as I go. I’ve read a few no-start threads and tried a few things. I’m wondering what to check next.


Was having an occasional hard start. Started it cold, backing out the drive, it stalled. Wouldn’t restart.


Was getting just a drip from the shrader on the fuel rail, and couldn’t hear the pump running.


Left it sitting for about 6 weeks.


Replaced fuel pump and regulator.

Getting a large squirt of fuel from the rail, and can hear the pump cycle when I turn it on, but it won’t start. It would need to be running to accurately measure fuel pressure?


My cheapo scan tool shows no codes set and I get no codes on the odometer with the key check (learned about that last night from another thread)
Not getting the NO-BUS message.


Disconnected the battery for a minute.


Was reading in the Haynes manual and wondering about pulling the coil rail to test.


When I first started to drop the tank I noticed the top vent line was disconnected. When we put it back together I hooked it up. The vent in the tank is open. I could hear it sucking air as I poured the gas off. I’m tempted to unplug it.


Maybe a shot of starting fluid?

Thoughts? Suggestions? Make Offer? Just kidding on that last one. This thing has been pretty easy to wrench on compared to the bowties I grew up around. I’m actually planning to pick up another in the future.

RandsGear

I tried starting fluid and it made one tiny putt and then no more.
Unplugged the vent line on top the tank. No change.
Removed the coil rail assembly but haven't tested yet.

Turbo X_J

Fuel pressure should be 49 psi +/- 5

RandsGear

The Haynes says primary resistance on the coils should be 0.97 to 1.18 ohms. We got approximately 10 for a reading on each. I'm going to try plugging the rail back in and see if I get any spark on this brake line as a ground test.

RandsGear

I'm not getting spark when I try the brake line test.
Oreilly and Advance say they can't test the coil rail. One suggested buying a new one and comparing resistance readings to mine and try the new one if the readings aren't the same.
My fuel pressure gauge only reads to 10psi. It pins the gauge when I turn it on.

Update-
I don't get any voltage to the coil rail.
I found my digital multimeter and we get 3.4 to 3.8 for primary from each coil and secondary resistance of about 14500 (in spec according to haynes) on each.
Unplugged the Crank position sensor and tested for resistance. Looking for a wiring diagram so I can tell which are the B and C.

RandsGear

It was the Crank Position Sensor. I picked up a new one and compared results. Mine was dead. Changing it was sort of a bear. Once we had it in the truck fired right up.
In the last 10k miles I've replaced the battery, water pump, eliminated the ac compressor, replaced the fuel pump, regulator, and this sensor. I think it's time to throw a fresh set of tires on it and run the h3ll out of it.

Crazy 8s

Good to hear you got it rollin again!

RandsGear

I got 80 good miles out of it. Started cutting out on me. Acting like it's starving for fuel. If I shut it off and let it set for a few minutes, it will run fine for a minute or two and then back to barely idling and sputtering out if I step on the gas.
I talked to an old timer at Autozone that says he wrenched for a living for fifty years and owns two of them, he says cam sensor. I was wondering if maybe my fuel gauge was sticking so I bought a can and dumped some in it. After sitting for the twenty or so minutes we were away from it, it ran fine, so I took it to AZ and let him plug it in. (it had set a code, the engine light was on but I'm not seeing a code on the odometer button test. His code reader gave a lean code (071) and he suggested it was the cam sensor or the MAP sensor.
I left out and pressed on with my day. It was running fine. Let it sit for a few hours, and then made 3 short stops about 5 minutes apart from each other, and then it started acting up again.
I went to AZ and got the Cam position sensor, and installed it in the parking lot. They let me borrow a ratchet and socket, I was shocked. It ran fine at first, but maybe a mile up the road and same thing. I left it sitting on a side street and need to retrieve it tomorrow. It's about 5 miles from home. I think if I go back to it I should be able to get a few miles before it craps again. Other than a drawbridge in downtown, I can side street it all the way and leave it sitting again if I have to.
So, what's next? what's left? Thoughts on the MAP sensor idea? I'm about to search on here and thumb through the haynes again.

RandsGear

It's not the MAP sensor. It's a little closer to home though.

Turbo X_J

What's the fuel pressure in psi?

*The Dude*

When you replaced the fuel pump, did you look for condensation in the tank to make sure you werent picing up water droplets. If you have some water or trash floating around in the tank you can get pockets of it in the fuel line that can cause problems.

When the vehicle wont run, are you checking it right then for fuel and spark?

An intermitent run problem needs these two things verified right when the no run occurs. Once you determin that you are getting spark and fuel pressure when its not running, then you can start checking for things like spotty fuel or timing issues.

I would bet that when you have this problem you will find one of the afore mentioned has stopped. If not, then I would say check the fuel tank for water and or debree.

RandsGear

I borrowed a fuel pressure gauge. After an hour of idling and revving in the driveway, I get steady pressure of 49psi and haven't been able to get it to sputter. I think I might have to drive it until it sputters and jump out and see what the gauge shows.

RandsGear

Got about 1.5 miles before it started sputtering. Checked the gauge, and it's not showing anything. Pulled the gauge and found a tiny particle in the valve and we thing we saw a tiny metal flake in the pressure relief tube on the gauge.
Let it set for a few minutes, and it will start, still not showing any pressure. I can hear it hiss if I loosen the fitting on the test port. It runs for maybe thirty seconds before it starts sputtering again.
Got it home, Pulled the core out of the test port and put a hose on it. I get just a trickle from it. The fuel looks fine. Didn't see anything in it.
I'm going to take this gauge back to the store and exchange it just to verify.

lil01cherokee

i know this sounds off topic but I had a similar issue with the sputtering, turns outs when I replaced my plugs I bumped one on the block and screwed up the gapping causing a misfire. have you checked the plugs yet fouled or bad gap

*The Dude*

Yeah...if its running and the gauge is showing 0 then its bad or you didn't get the Schrader pushed in when you screwed it on.


Your description makes me think again that you got a bit of water or debree floating around in the bottom of the tank. When you are sitting still that little bubble of debree/water could be some where away from the fuel pump sock allowing it to run fine while sitting still. You get in it and drive and the first turn you make sends that little floating bubble of gunk moving around until it come into contact with the fuel pump sock...it sucks a bit up and presto...no run. Then it sits and floats to another place while it sitting and you then try to start it. The gunky fuel gets sent back to the tank in the return line and it picks up some good fuel that runs its way through the line until you drive it again stirring up the gunky fuel and again you get the bad fuel that stops the motor.


I know its a pain, but it might be well worth taking a look inside the tank....