Quick question

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Gonzo1970

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Sep 30, 2018
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Replaced a broken O2 sensor and the warm idle dropped like a rock.. like 400rpm and quit once at a light. At Very light throttle it seems to surge.. but I think that's because the warm idle is so low?

the pickle is I replaced the fuel filter at the same time... the right way... and when I did, there was no fuel in the line even tho it was just shut down 5 minutes prior.

Adjust idle because of new O2 and replace the fuel pump is what I'm leaning towards.. what do y'all think?

-Gonz
 

TURNA

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Sounds like your pump is bad and it was throwing your O2 sensor off do to the lean mixture
 

Gonzo1970

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Sep 30, 2018
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Sounds like your pump is bad and it was throwing your O2 sensor off do to the lean mixture

Fuel pump is where I was heading, yea..

doesn't the computer have to relearn when you install new components?

I hadn't thought of that.. I will give it a go.


Thanks guys

-Gonz
 

Gonzo1970

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Sep 30, 2018
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Reset the computer. Got a little better. Surge at Very Light throttle went away, but idle is still 400rpm, warm, in gear.

Going to adjust, then get a fuel pump. Even if its Not the fuel pump, its been on my list to replace since its probably factory (34 years, 63k)

-Gonz
 
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pontiacgp

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Mar 31, 2006
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I would drive it a day or two before I changed or adjusted anything. It may take a few miles before the computer has relearned
 
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69hurstolds

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Jan 2, 2006
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Bump your idle up now. Don't think that's going to get better. And if it does, you can always adjust it down again. I think the fuel mixture is a bit lighter now that it was with the O2 sensor back in business.

Drive it for a couple of days, see what happens as pontiacgp suggested.

Fuel not being in the line might be the fuel leaking back to the tank through the return line. Which isn't normally going to be found if you daily your car since there will be enough in the fuel bowl left to start the car and refill the bowl before you realize it was draining the line. Check the oil JUST IN CASE for gas in the event the diaphragm has a hole in it.

Only way to fix that if it's one or the other is......a new fuel pump. Since you were replacing it anyway, then it's a moot point.
 
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pontiacgp

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when I had a fuel pump going it would idle fine but on the highway it would die under acceleration
 

Gonzo1970

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Sep 30, 2018
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Bumped the idle up from 600 out of gear and 400 in gear to 850 out of gear and 650 in gear.

Runs great.

Still going to replace the fuel pump tho...

-Gonz
 
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pontiacgp

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if it ain't broke don't fix it, without a fuel pressure gauge you are just guessing and you may be throwing away a better fuel pump than the aftermarket pump you'd be installing
 
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