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  #61  
Old September 18th, 2019, 18:34
rain164845 rain164845 is offline
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Blowing smoke from exhaust

I put a fuel pressure gauge on the Schrader on the fuel rail. Read 0 after cycling the key 5 times without cranking. I had my wife crank it, and pressure only got up to 10 psi while running.
How do I diagnose from here? Probably the ancient fuel filter, I would assume.


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  #62  
Old September 18th, 2019, 18:51
RCP Phx RCP Phx is offline
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Re: Blowing smoke from exhaust

Some of it to fix isn't bad. The fuel pressure regulator is on the rail and you have a fuel filer on the frame rail but, the fuel pump is in the tank.
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  #63  
Old September 18th, 2019, 21:06
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4x4JeePmaNthINg 4x4JeePmaNthINg is offline
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Re: Blowing smoke from exhaust

I haven't read of it yet, but your fuel level is determined by a float. If this is damages or not functional, it could explain this gauge issue. This combine with your fuel pressure lacking is odd. 5 gallons should be enough to read 1/4 tank.
Try key on to run about 5 times, do not start the vehicle. This should prime enough through repetition to get a reading from the fuel rail. At this point note your reading and then start the jeep. Get an idle reading and watch the fuel pressure gauge as you open the throttle plate slowly to increase rpm.
This will give you a good idea as to weather the fuel pump is toast, or a check valve has failed.


Otherwise , yes bad wiring could be an issue, but I doubt it unless you have good reason to suspect this.


To me it sounds like someone drove your rig into zombie status lol.
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  #64  
Old September 19th, 2019, 01:35
Down under Down under is offline
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Re: Blowing smoke from exhaust

I would be tempted to Jack it up high at the back, remove the pump/ filter. Get a decent container and dump some fuel into. Chances are it probably has crap in the tank anyhow,
Fine filter the fuel and repeat as needed. Test the fuel pump whilst out. Carefully but!
Maybe use deisel? Bit less flammable..
Disconnect all your fuel injectors, and perhaps blow some air pressure up the line and parts cleaner.
Correct me guys if there is any valves/etc that can be damaged. Old school way.
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  #65  
Old September 19th, 2019, 15:12
rain164845 rain164845 is offline
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Blowing smoke from exhaust

So, I was able to build about 15 psi through a few starts. The pressure bleeds off very quickly to 0 once the engine is turned off. Maybe injectors failed open? I can't imagine that a failing tps or iac would cause this.

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  #66  
Old September 19th, 2019, 15:13
rain164845 rain164845 is offline
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Blowing smoke from exhaust

Also a that test was done with a new fuel filter

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  #67  
Old September 19th, 2019, 17:09
lawsoncl lawsoncl is offline
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Re: Blowing smoke from exhaust

I believe a 1992 still has the fuel pump ballast resistor on the fender. Check that it's not messed up or broken. You can eliminate the resistor and connect the wires together, as the resistor was added to reduce the voltage while running for noise reasons. If you have a meter, check that you're getting voltage to the fuel pump. To me the bleeding down quickly points to the fuel pressure regulator, fuel pump, or a badly leaking injector (which could contribute to your sludge and/or smoke). I'd maybe unhook the fuel filter and key-on to see if it's flowing well.
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  #68  
Old September 20th, 2019, 00:44
Down under Down under is offline
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Re: Blowing smoke from exhaust

You probably have a heap of knock on symptoms. Great info coming in to help you, and we all learn from it.
Pretty sure you guys over there can get parts heaps cheaper than us here.
Consider a 2nd hand head, get it decked and cleaned up etc,.
Then later get your original one done up in time when cash available.
Or swap for exchange head.
A lot can be fixed with your own time without spending big bucks.
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  #69  
Old September 20th, 2019, 05:57
CJR CJR is offline
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Re: Blowing smoke from exhaust

The in-tank fuel pump has a check-valve to hold pressure & fuel in the line to the injectors. When the in-tank fuel check-valve fails, fuel flows back into the tank and empties the fuel line and fuel pressure can't build-up. This happened on my 88XJ. You can replace the in-tank fuel pump/check valve assembly OR you can just install an inexpensive aluminium check-valve downstream of the fuel filter. I added an external check-valve on my 88XJ and the problem was solved. The fuel regulator, on the fuel rail only regulates fuel pressure, it is NOT a check-valve.

Best regards,

CJR
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  #70  
Old September 20th, 2019, 13:18
rain164845 rain164845 is offline
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Blowing smoke from exhaust

Could my smoking problem have messed up an injector? Does that happen?

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  #71  
Old September 20th, 2019, 14:42
Down under Down under is offline
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Re: Blowing smoke from exhaust

I doubt it very much.
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  #72  
Old September 20th, 2019, 15:08
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Re: Blowing smoke from exhaust

Quote:
Originally Posted by rain164845 View Post
So, I was able to build about 15 psi through a few starts. The pressure bleeds off very quickly to 0 once the engine is turned off. Maybe injectors failed open? I can't imagine that a failing tps or iac would cause this.

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You don't want to start it a few times, just key on to run like 5 times, then on the 6th start it.

If your injectors are leaking it'll start in flood mode and a bit rough.

What color smoke?
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  #73  
Old September 20th, 2019, 15:19
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Re: Blowing smoke from exhaust

*correction, if injectors are leaking it'll start flooded. Starting in flood mode, if the same on your year, would be by holding the gas pedal down all the way, then starting.



Tps/iac hasn't anything to do with starting fuel pressure. Only check valve/pump or injectors, Other wise ide think there would be fuel leaking under your ride....ha


You could pull the rail and prime 5 times like I said earlier, then see if an injector leaks. Just don't try starting it.
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  #74  
Old September 20th, 2019, 16:08
rain164845 rain164845 is offline
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Re: Blowing smoke from exhaust

Quote:
Originally Posted by 4x4JeePmaNthINg View Post
*correction, if injectors are leaking it'll start flooded. Starting in flood mode, if the same on your year, would be by holding the gas pedal down all the way, then starting.



Tps/iac hasn't anything to do with starting fuel pressure. Only check valve/pump or injectors, Other wise ide think there would be fuel leaking under your ride....ha


You could pull the rail and prime 5 times like I said earlier, then see if an injector leaks. Just don't try starting it.
Based on that I'm thinking Fuel pump. Preferred one today along with iac and girl pump relay. If that doesn't fix it then I'll do injectors

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  #75  
Old September 20th, 2019, 22:02
Down under Down under is offline
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Re: Blowing smoke from exhaust

Are you getting a lot of condensation at the exhaust
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