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Discussion Starter #1
Let's get down to the nitty gritty.
99 XJ 4x4
4.0 Auto
147000 miles

It runs without fuel going to it and a shot of starting fluid. But....

Got Fuel - 49 lbs while starting and about 46 once I stop and it holds
Got Spark - pulled several different plug wires, shoved old plug in it and got fire.
Got compression - compression tester.. wooooo

Exhaust smells like fuel, Noid light pulses on injectors..

I can pull the fuel pump relay, clear and dry out the cylinders and plugs, spray in some starting fluid and it'll run for 10 seconds. As soon as I toss the fuel pump relay back in it dies and it goes back to not wanting to run.

Pumped about 12oz of fuel from the rail into a clear bottle and do not see any hint of water. But doesn't mean there isnt any in it or just too much I cant tell.


How it started:
Bought it a month ago. Drove it from Bama to VA (920 Miles) without a single problem. Looked at houses all day with the real estate agent. Came back drove it to dinner. Got back in drove to a friends and as we pulled into their road it started sputtering. Next morning it would not run. I have until Saturday to get it running or I am going to take it to a shop and let them rip me a new asshole. I have no other choice at the moment as I don't have a house here yet, living in the barracks, and barely have any tools.

Brain is in shutdown mode at the moment, cant think of what else.
 

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Sounds like the crank position sensor..,and at under $40 and 2 p.i.t.a bolts I'd start there
 

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Discussion Starter #3
It's not the CPS. I have spark and fuel. Rules put CPS. Plus it has been replaced with a known working one.
 

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If it runs on starting fluid it's got to be fuel-related. Fuel filter maybe? And I think you may be on to something with the bad gas idea... pump some into a clear jar by removing the line and cycling the ignition, then let it sit. Water will pool at the bottom if it's there.


Jake
 

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Discussion Starter #5 (Edited)
We did that last night and never saw anything in the fuel. I'm still thinking of just draining it all anyways and clearing the lines then put fresh gas in it.

The filter is in the tank so would have to remove the tank anyways to drain it properly.

I've asked a few mechanic buddies and they claim the coolant temp sensor on the tstat housing or a bad o2 sensor can cause it to push too much fuel and not start. It also will not throw a check engine light. So I am going to see about testing those this afternoon.

Just wish I had an OBD scanner to help out. May purchase one in the near future.
 

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Try dropping your tank some so you can get to the line. When you turn the key, you should be able to the fuel pump hum. If you disconnect the line going to the engine and turn the key, this should shoot out some gas. Just because you're building up pressure, that doens't mean it's pumping what it should be. Make sure you have pressure at the rail and pump.

If you have spark & you have fuel, then that means the ASD relay is energizing and that requires that both the crankshaft and camshaft position sensors are putting out their required signals.

If all else fails do what you said, drain the gas, refill and use some HEAT in it.

I have never heard of an oxygen sensor causing a car not to start, or your coolant temp sensor either. A bad oxygen sensor will through the check engine light and a code as well, at least it has on multiple vehicals I own.
 

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Discussion Starter #7
In my OP I mention where I already tested fuel pressure. It's within specs.

Going to drain the tank tonight.
 

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Discussion Starter #10
I can push the pedal and nothing


Pressure was tested at fuel rail. Just volt and ohm tested the MAP, TPS and coolant harnesses. All read correctly so at least they are getting supplied with adequate power.
 

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I think everyone is right about it having fuel issue. If it was anything else, it wouldn't run with starting fluid.

Have you checked your spark plugs to see if they are fouled?

What about the injectors? (I don't know how to test those.)

E
 

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Discussion Starter #12
I have pulled and cleaned the plugs numerous times. They definitely get gas washed after turning it over a good bit so I pull one by one and clear the cylinders as well. I have not tested the injectors themselves but I did use a noid light to make sure they were receiving a signal. Each one pulses correctly so that's good. Each cylinder also gets fuel so the injectors at least pump. Even if one or a few went out it would still try to fire. I get nothing, not 1 single cylinder trying to fire.
 

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What were the cylinder pressures?
You may have a timing issue caused by a bad timing chain, or partially striped cam gear. Generally, this will show up as low compression, as indicated by the engine turning over very rapidly, as if all of the spark plugs have been removed.
If your getting too much fuel, you can try pushing the pedal to the floor--this will cause the ECM to turn off all injectors; it's called "clear flood" mode.
It's possible your fuel pump volume is low. You can test it by disconnecting the fuel line and directing the flow into a measured container and determine how long it takes to pump a liter of fuel (by pass the fuel pump relay, and connect 12v directly to the pump). You should get at least 1 liter per minute.
 

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I just re-read your original post.

.....

I can pull the fuel pump relay, clear and dry out the cylinders and plugs, spray in some starting fluid and it'll run for 10 seconds. As soon as I toss the fuel pump relay back in it dies and it goes back to not wanting to run.
.....
There are a couple of thinks that come to mind.

There's an auto shut off feature that cuts power to the fuel pump when the ECM senses a critical problem. You can jump the fuel pump relay socket at the power distribution thingy under the hood. When you jump it, the pump should shut off within a few seconds. If it doesn't, then it's your fuel pump. After you jump it, turn it over. It it starts, turn it off IMMEDIATELY!! You'll have to figure out why the auto shut off safety feature is being triggered.

What happens if you squirt starting fluid in the throttle body with the relay in?

E
 

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Discussion Starter #15
I just re-read your original post.



There are a couple of thinks that come to mind.

There's an auto shut off feature that cuts power to the fuel pump when the ECM senses a critical problem. You can jump the fuel pump relay socket at the power distribution thingy under the hood. When you jump it, the pump should shut off within a few seconds. If it doesn't, then it's your fuel pump. After you jump it, turn it over. It it starts, turn it off IMMEDIATELY!! You'll have to figure out why the auto shut off safety feature is being triggered.

What happens if you squirt starting fluid in the throttle body with the relay in?

E

If I do it with the relay in it does nothing. Only after I have cleared the cylinders and dried the plugs without the relay does it run on starting fluid. I am positive the pump and all is good as I can hook up the pressure gauge to the rail and hold the relief on the gauge and fill up a fuel can. I have pumped about a gallon out of it within the past few days. Had another mechanic who has worked on many Jeeps claim the coolant temp sensor on the thermostat housing will cause it to flood and not start. Just sounds weird to me. I may just end up taking it to him and pay the premium.
 

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I would steer clear of that mechanic. I have NEVER encountered that situation. It's virtually impossible for the temp sender or the housing to cause it to flood. If it makes you feel any better, you can change the housing and the temp sending unit yourself before taking it to anyone.

I will wash your Jeep for a year if you do it yourself and it fixes the problem.

E
 

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You also might want to check your checl-valve at the fuel pump. Sometime you get some gunk in there that will prevent from closing all the way. The purpose of it is to retain the pressure when the engine is shut off. Also check your ADS relay, if you're getting a weak spark check your ignition coil. I'm running out of thigs to tell you to try.
 

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Discussion Starter #18 (Edited)
I put the pressure gauge on it for over an hour yesterday and the pressure never dropped below 45 lbs. So the check valve should be good.I have swapped all relays around and does not make a difference.

As far as the coolant sensor, 2 people so far have claimed that the sensor tells the computer if it needs more fuel for a cold start. If it is bad it can tell it to send a LOT of fuel and flood it out. The flooding issue sounds right to me because if I try starting it and keep it turning over for say 10 seconds or more (3-5 seconds is how long the pump runs if the vehicle is not running) it will start to bump a few times when I let off of the key. Kinda like it wants to run after fuel has stopped going to it. But it will not bump while I am cranking it. Only right when I stop trying to crank.

This is so damned confusing. I am not a complete idiot but this makes me feel like one. And this week is not the week for me to deal with this BS.

I apologize now if I have sounded like a smart ass, just extremely frustrated and am posting this on NAXJA and JF also with no answers so far. I have checked everything that has been mentioned to no avail. Maybe a few 12 gauge slugs to the block I can get insurance to pay for it.
 

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I had a Nissan 240 SX once that had almost the exact same symptoms, and it was in fact the coolant temperature sensor that cured the problem. It was running fine, then all of a sudden it got to where it wouldn't start for shit. A mechanic told me to bypass it and see if it would fire off, and that worked. I replaced the sensor and it ran fine afterward. I'm not saying the Jeep system is the same, but if you can find the resistance value of what the sensor should be, you can measure yours and at least rule it out for sure.

And I know how you feel right now. My DD car was giving me fits a few weeks ago. I tested lots of things, replaced a few things and the fawker would never act right. I finally had enough and took it to a family friend that owns a shop. It turned out to be one of the parts I'd already replaced that was bad out of the box :laughing:
 

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Discussion Starter #20
Well 2 seconds before I was gonna pull the tank we found an old Blaster Coil. Rigged up some pins and alligator clips with some 14ga wire and she fired up. We even checked the spark again and it was sparking fine. Nice and bright blue. But we figured what the hell and try the other coil anyways. So I went to advance auto and snagged a new coil and now she's running. I haven't been so excited since my kids were born. Haha
 
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