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98 Sahara 03-08-2010 09:50 PM

fuel pump?
What is the spec PSI for a 98 6cyl wrangler at the fuel rail? I just moved and am having a problem locating my manual.
My problem is my jeep sputters and wants to stall if I do anything but drive it around slowly. I checked the pressure. It was 44PSI. A guy at autozone said it should be 95-115. I also have 2 codes. I had them check the codes and it came up fuel pump and oxygen sensor.

4Jeepn 03-08-2010 10:18 PM

I want to say 100 is more like it. Also, just to rule it out, check the connections for the fuel pump just above the rear diff near the tank.. some times the wires can get loose and cause issues... I think the pump is the green or black or green with black wire...been a while.

SPDNJOE 03-08-2010 11:22 PM

It should be around 43 at idle.
Injectors are rated by the amount of fuel they deliver at a given pressure, either 39 or 49 psi for 4.0Ls depending on year.

98 Sahara 03-09-2010 07:17 AM

So I checked the pressure at 44psi so it must not be the fuel pump. Any ideas on what the problem might be? It's really bogs down if I give it any gas. Starts with no problem. It has sat a couple weeks, but that's been the norm for it for the last couple years. Check engine light is on and gives fuel and oxygen sensor codes.

Fweaky 03-09-2010 08:03 AM

Might be the throttle position sensor if it runs okay until you hit the gas.

98 Sahara 03-09-2010 09:03 AM

Unfortunately since I originally listened to the Autozone guy before deciding to research a little more, I have already dropped the fuel tank. So to test anything else I'd have to put it back. Not to say that would be terrible, but with twins, time to work on my vehicles is scarce. Anyway, my question is, even though I checked 44psi at the fuel rail during idle, is it still possible the pump may be not functioning properly under acceleration? Should I just put in the new pump or do you think that is probably not the problem. It would be a $220 risk. Another note. I have thought for some time the engine felt somewhat weak and it "chugs" under heavy acceleration, or when I pull about 1000 LBS.

4Jeepn 03-09-2010 09:57 AM

Is it possible to have the fuel pump tested? also try should be under 220 on the pump there.

98 Sahara 03-09-2010 11:58 AM

I checked it at the fuel rail at 44 PSI.

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