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Fuel pump question


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91 loyal FI With less than 1/2 tank of gas, it likes to stall out at stop signs, or surge ahead after almost stalling. Fill the tank & it runs great till you get to about 1/4 tank & starts the process over again. No cel. I replaced the pump with a pull n save pump when we first bought it about 2 months ago due to the little rubber tip on the end being gone & spraying fuel everywhere. Then this starts shortly after.

 

I browsed some sites last night looking for fuel pumps & they had a note in the description saying alot of fuel pump issues are actually fuel pressure regulaters issues. Any thoughts on this?

 

Thanks in advance.

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could you have bad gas or water in the gas.....filling up just dilutes the bad stuff enough that you don't notice? first i would try lots of whatever gas treatments you use to remove water. if you still had the old pump you could swap it on (eventhough it sprays) to see if the problem goes away.

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Well they are right, especially with electric fuel pumps. Get a fuel pressure gauge on the car and watch it. Fuel pump issues tend to be continous, and not related to the fuel level of the tank, ie starvation on heavy throttle.

Have you tried removing the gas cap when this problem happens. It could be a vaccume lock in the tank, which can be traved back to the charcoal canister system.... that would always occure at the same tank level.

 

nipper

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Grrrrr. I was just about finished typing this in & I accidently hit the clear button on the keyboard. Poof gone.... :banghead:

 

ANYWHO, I have a retired master mech friend who agrees with the gunk / water in the tank theory. I threw a can of Heat in the last tank to see if that helps, Any other suggestions on Brand? I toyed with pulling the tank & flushing it out till I read manual & figgered it was kinduva job...

 

No on the vapor lock. Not when I refill the tank anyway. Old pump is gone, But It may be worth a trip to pull n save again to try & rule it out.

 

Could the fuel pressure reg. be causing this???

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Could the fuel pressure reg. be causing this???

 

Not to my knowledge.

 

 

One possibility from way out in left field: My car occasionally starves for fuel while stopping or turning below 1/4 tank. This is because my car started out with a carburetor and was converted to fuel injection later on. The F.I. fuel tanks have some baffles inside that keep plenty of fuel available to the pump at all times, but they didn't have those on carbed cars (no need). It may be possible that your car had a tank put on it from a carbed soobie, due to the original one rusting out or being damaged.

 

That is HIGHLY unlikely, but something to consider if the problem doesn't go away.

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ARe the tanks on trhe 91's like the later legacies. The fuel pump is accessed from a plate inside the car ... and its a split tank if its AWD, or is just on tank. i was thinking if it is a fuel qaulity issue... remove the cover, take a jar wiht a cord attached to it. Get a feul sample and let it sit for 1/2 hr then examine it, If it is contmainated fule it will be seen in the jar. If this is the problem your going to have the tank cleaned, otheriwse you eil never get rid of the contamination.

 

Just a thought.

 

nipper

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no that wont work .... and im getting a better understandong now. the idea is to take the sample as it sits unstirred in volume of the tank, at the level it happens. Have you checked the sock filter in the tank?

With it being an external pump, i may start to agree with contamination. With the external pump, you can always dissconnect the hose, hot wire the pump, and drain it all out that way... but stl no guarente that you will get it all. Sounds like you need to drop the tank and get it cleaned.

 

nipper

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Nope on the sock filter... How would an individual go about that? I read on some models you can pop the back seat, remove an access cover, & get to the sending unit. Would the sock filter be there, or did I just fall for the "check the muffler belt" routine? :grin:

 

thanks for your help guys. jerry

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