Fuel check valve or leaky injectors?
#1
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Year: 1996
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Fuel check valve or leaky injectors?
I've got a 96 XJ and it's had the issue of not starting on the first, or maybe even the second crank. I already know what's causing the issue but does anyone know if it sound like leaky injectors or the check valve.
Thanks
Thanks
#4
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Why do you ask if you know? Get a dual gauge fuel pressure tester that can isolate the system so you know what side the leak is on. Or pull the fuel rail, set it on paper towel to see if it is the injectors that are leaking.
#6
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#7
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Year: 1996
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Ok, I'm sorry to bother everyone for what seems like a question I answered myself, but what I meant by "I already know what the problem is" is that I think it's either the check valve or the injectors. I was asking because I was wondering if anyone else had this situation, and if anyone knows specifically what it is.
I just said that to partially answer the question because I thought that would make it easier to understand what's going on.
Sorry for the trouble,
Paul
I just said that to partially answer the question because I thought that would make it easier to understand what's going on.
Sorry for the trouble,
Paul
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#9
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Nah, not yet, that's why I came here. I try to do as much as I can before I come here and annoy everyone for stupid, simple issues. I know we're all a community here blah blah, but I don't like to bother people with stupid questions when there's people with bad problems on their dd jeep, and they can't get to work...etc those are the important questions, those should be answered first.
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Year: 1996
Model: Cherokee
Engine: 4.0
You can isolate the problem if you have a fuel pressure gage.
1. Connect the gage at the fuel rail and start the engine. The gage should read 49 psi plus or minus 2 psi (for my 96 XJ 4.0 anyway).
2. Turn the engine off and immediately clamp the fuel line just ahead of the fuel tank. Watch the pressure gage and see how long it takes to lose pressure.
If the pressure remains at 49 psi for an extended time then the problem is in the tank - probably the check valve. If the pressure falls below 49 psi fairly rapidly then the problem is in front of the tank - probably a leaky injector.
In my case the fuel pressure would drop from 49psi to zero within 30 minutes after sutting off the engine. If I clamped the line it will hold 49 psi for hours. I concluded the problem was the check valve. I installed an “in-line” check valve in the fuel line near the fuel filter and solved the problem. At $10 it was much cheaper and easier than replacing the fuel pump.
Hope this helps.
1. Connect the gage at the fuel rail and start the engine. The gage should read 49 psi plus or minus 2 psi (for my 96 XJ 4.0 anyway).
2. Turn the engine off and immediately clamp the fuel line just ahead of the fuel tank. Watch the pressure gage and see how long it takes to lose pressure.
If the pressure remains at 49 psi for an extended time then the problem is in the tank - probably the check valve. If the pressure falls below 49 psi fairly rapidly then the problem is in front of the tank - probably a leaky injector.
In my case the fuel pressure would drop from 49psi to zero within 30 minutes after sutting off the engine. If I clamped the line it will hold 49 psi for hours. I concluded the problem was the check valve. I installed an “in-line” check valve in the fuel line near the fuel filter and solved the problem. At $10 it was much cheaper and easier than replacing the fuel pump.
Hope this helps.
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#14
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