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HELP!! changed fuel pump now runs really bad

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Old 09-15-2010, 06:24 PM
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Default HELP!! changed fuel pump now runs really bad

Had to replace my fuel pump after running out of gas. I replaced the whole sending unit with the pump. I also changed the fuel filter. It will start now but sputters when I give it gas. Hard to get up past 15 MPH. Bad smell from the back also. Will idle for a while but will eventually stall out. This is my DD so any help would be great.

Thanks
BIH
Old 09-15-2010, 06:26 PM
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Might have melted the converter if you ran out at high speed, the lean-out condition can play heck with the core.,
Old 09-15-2010, 06:47 PM
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What does the bad smell smell like? Gas or rotten eggs? Did you install the pump corectly? Is it the correct pump? Did you break any hoses or lines? Is there a leak between the pump and engine? See where I'm going with this?
Old 09-15-2010, 08:11 PM
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The smell was like a burnt smell. The pump was the correct one and I'm pretty sure I installed right. Any idea how I could have installed wrong? I checked all the lines and they looked good. I checked the filter also. The only other thing I did was install a new ballist resistor.

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BIH

Last edited by BIGISLANDHIKERS; 09-15-2010 at 08:15 PM.
Old 09-15-2010, 08:50 PM
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One other thing...would my 89 4lt 6 straight be a TBI or MPI system?
Old 09-15-2010, 09:21 PM
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Did you install the feed and return lines backwards?
Old 09-15-2010, 10:21 PM
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Multiport
Old 09-15-2010, 10:26 PM
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There is 4 bolts in the flange at the catalytic converter, unbolt it and leave it loose to see if it runs better, sign of a plugged catalytic converter.
Old 09-16-2010, 11:29 AM
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Originally Posted by DualSportDad
Did you install the feed and return lines backwards?
I marked the hoses but I will double check.

Thanks
BIH
Old 09-18-2010, 05:25 PM
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I rented a fuel pressure kit from autozone. When I first start the jeep I have about 25 psi. Removing the vac hose from the regulator makes no difference. As the jeep runs the pressure slowly drops to about 16 and it stalls. When I pinch off the return hose the pressure actually drops way down to about nothing. I thought it would climb when I did this.
Any ideas??
Thanks
BIH
Old 09-18-2010, 05:54 PM
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Originally Posted by BIGISLANDHIKERS
I rented a fuel pressure kit from autozone. When I first start the jeep I have about 25 psi. Removing the vac hose from the regulator makes no difference. As the jeep runs the pressure slowly drops to about 16 and it stalls. When I pinch off the return hose the pressure actually drops way down to about nothing. I thought it would climb when I did this.
Any ideas??
Thanks
BIH
Did you flush the tank when you replaced the filter and pump? I replaced an in tank filter once and it stirred up the crap in the tank and plugged the new filter after about 2-4 minutes.
Old 09-18-2010, 07:51 PM
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I just installed a new in tank pump and filter 4 months ago and all was good for about three-four weeks and then it started acting up again. I did not however flush the gas tank. How should I flush the tank. Can I use soap and water or something else?
Old 09-26-2010, 08:43 PM
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I have narrowed down the symptoms. When I first start the jeep the pressure is right where it should be, about 31 pounds. After running about a minute the pressure starts to drop eventually down to about 12-15 untill it stalls. It does this whether I give it gas or not. If I restart rightaway the pressure is low, around 20 and it drops until it stalls. If I let it sit for about 20 minutes before I restart the pressure is good again. So it seems giving the pump(or something else) some rest improves the pressure.

Does it sound like the replacement pump could be bad?

Thanks
BIH
Old 09-27-2010, 08:45 PM
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bump
Old 09-27-2010, 08:55 PM
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i would try a new pump , and check it again,


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