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Discussion Starter #1
ok, so finally after getting the new pump installed in sept with new fuel filter/reg combo from acdelco at the same time, i got the car to idle, and run correctly. the tune in it sucks now, but its ready to be tuned correctly now. here is the run down.

-car was leaking fuel from on top of tank.
-take to dealer, have them replace fuel lines from pump to filter, replaced the pump, replaced the filter (never was done)
-all parts installed, took to tuner as soon as it was assembled, he tuned the car. it never idles corrected (sounded like it had a cam) and drivability was horrible. figured tuner sucked, so had it retuned 6 times, got idle better, drivability was still horrible. - it would shutter really badly when decelerating, throttle response was horrible (big lag when you would start to accelerate from a stop, after slowing down applying slight gas would load the car up pretty bad)

finally started thinking, hey, maybe the tuner doesnt suck, maybe its something else.

-replaced filter/reg combo
-replaced pump (cut hole in floor, very easy to do honestly, can post pix if anyone needs)
-checked all lines to see if they were bent or clogged.

this process has taken forever. in the end, it would found to be this.

the fuel pump i purchased had a regulator ON THE PUMP (if you get a new pump check this!!! very important!!) and the fuel filter i purchased has a regulator in it (the one that costs over 100 has a reg in it, the 10-20$ ones do not). this was causing the issue. went to oriellys bought the filter from an 06 cobalt ss (as tim had suggested since they are the same, which they are BUT DO NOT LOOK THE SAME!!) installed the part. fuel pressure dropped from 85-95psi at the rail to jumping between 55-65psi at the rail. my tune is dog poop and i was using a cheap gauge that caused the jumping around. but, figured id post this up because it caused me a lot of wasted money and even more frustration.
 

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06' STS V
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ok, so finally after getting the new pump installed in sept with new fuel filter/reg combo from acdelco at the same time, i got the car to idle, and run correctly. the tune in it sucks now, but its ready to be tuned correctly now. here is the run down.

-car was leaking fuel from on top of tank.
-take to dealer, have them replace fuel lines from pump to filter, replaced the pump, replaced the filter (never was done)
-all parts installed, took to tuner as soon as it was assembled, he tuned the car. it never idles corrected (sounded like it had a cam) and drivability was horrible. figured tuner sucked, so had it retuned 6 times, got idle better, drivability was still horrible. - it would shutter really badly when decelerating, throttle response was horrible (big lag when you would start to accelerate from a stop, after slowing down applying slight gas would load the car up pretty bad)

finally started thinking, hey, maybe the tuner doesnt suck, maybe its something else.

-replaced filter/reg combo
-replaced pump (cut hole in floor, very easy to do honestly, can post pix if anyone needs)
-checked all lines to see if they were bent or clogged.

this process has taken forever. in the end, it would found to be this.

the fuel pump i purchased had a regulator ON THE PUMP (if you get a new pump check this!!! very important!!) and the fuel filter i purchased has a regulator in it (the one that costs over 100 has a reg in it, the 10-20$ ones do not). this was causing the issue. went to oriellys bought the filter from an 06 cobalt ss (as tim had suggested since they are the same, which they are BUT DO NOT LOOK THE SAME!!) installed the part. fuel pressure dropped from 85-95psi at the rail to jumping between 55-65psi at the rail. my tune is dog poop and i was using a cheap gauge that caused the jumping around. but, figured id post this up because it caused me a lot of wasted money and even more frustration.
So the regulator is on the pump?
That means I can just get the cheaper fuel filter?
 

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Discussion Starter #3
They changed setups in 07. Tim stated his reg was not on the pump. Mine is an 06, but never saw the pump they removed. Since the replacement was OEM I'd guess its on pump from factory in 06.
 

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06 sts-v
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What I've ran into with mine with lower pulley tims tune spectre intake tb and injectors it's lean on top got a kenne bell boost a pump started installing monday gotta finish wiring up and going to go log but mine was lean up top and I melted a piston so be carful!!
 

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2006 STS-V and 2007 STS-V The Murdalac
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I must add that the melted piston was with someone else's tune. No one's ever done that with my tune.
 

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Discussion Starter #10
My idle is dead on. 14.4-14.7. Never moves out of that range once warmed up. I have never had an issue with running lean up top. Excluding when fuel leak was there then after the dealer screwed my rail pressure. Should be good now. But if not I have another fuel pump ready to be installed so I don't care.
 

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black 08 sts-v
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3 Posts
I am trying to replace the fuel pump module in my car. What pump did you use, and did you have to change inectors or electrical?
 

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06 sts-v
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Oh ye sorry Tim, car was tuned by somebody who didn't know what they were doing which caused meltdown didn't mean to make it sound that way
 

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Discussion Starter #13
second time i got a carter pump. bought the last rockauto had in stock. i think they can be found on ebay now. you need to do nothing but change the pump is everything is stock. i cut a hole under the rear seat and gained access to pump that way. hit the lock ring off with hammer and long screw driver. disconnected the fuel fittings on the top of the pump and electric connector . started pulling the pump out (you will find there is a crossover hose attached to bottom of pump!!! you need to push the two square tabs OUT then pull the hose off the barb, makes sense when you see it trust me) put new pump in and your done.

please do us a favor and take pix of the stock pump that you remove!!!! and also list the year of your v. trying to figure out wtf the deal is with the alldata info not being accurate
 
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