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Discussion Starter #1
I recently had the fuel pump swapped out to correct the slow pump prime on cold starts. Drivability and performance has improved with the new fuel pump and power-cleaned injectors, but the invoice says it's at 58PSI (original test was 45PSI with key on, engine not running, and 35PSI with engine idling). My HAYNES shop manual says THOSE are the correct specs, but the dealer told me it was too low and is the reason I was having cold start issues from time to time.

So who do I believe? And is there any harm in running the car with 58PSI (the receipt did not specify whether the engine was on or of at the time of reading)?

I also have a fuel gauge reading issue after the pump swap (which they did troubleshoot with another new pump assembly w/sending unit). They tested both new units and my old unit (the new sending units put out 90 ohms, my original one 103 ohms). They told me they tweaked the float (not sure how that was done, but they told me they did not bend it).
 

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Discussion Starter #3
Invoice shows 58psi. Was told it needed to be 55-60 for this car (and this was at a GM dealer)

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Discussion Starter #4
Is it possible they installed the incorrect fuel pump assembly (i.e. for the LS1 car vs my LT1)? Asking because I also have an inaccurate fuel gauge as a result of this (which I already brought it back to correct, and they told me they needed to "tweak" the float).
 

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Is it possible they installed the incorrect fuel pump assembly (i.e. for the LS1 car vs my LT1)? Asking because I also have an inaccurate fuel gauge as a result of this (which I already brought it back to correct, and they told me they needed to "tweak" the float).
Tweak the float? What?

Might be the wrong pump.
 

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Discussion Starter #7
Part number on invoice was 19179528 (which I googled, and came up for 96-97 f-body cars). I might have to go there and ask more questions.

Is it even possible to install an LS1 fuel pump successfully in an LT1 car?
 

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Discussion Starter #8
Went back to the dealer and they admitted that they were referring to a 1998 model regarding the correct fuel pressure. However, the part they ordered is the correct part (they order parts based on the VIN number, so I assume it is correct).

I guess I need to re-check the fuel pressure on my own? Not sure why they specified 58PSI on my invoice after the repair.
 

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Discussion Starter #10 (Edited)
Well, I now have a much bigger issue to deal with.:craz28:

Now the car will not start at all! Had it out this morning, came back home. Was about to go back out, and now it won't start up (cranks but won't fire up).

Needless to say I already called the dealer to arrange for a tow truck to pick my car up and fix it. Also mentioned the gas gauge issue is still not fixed either (gauge read 1/2 this morning when I filled it up, it took just under 5 gallons).

EDIT - Fuel pump did prime for 2-3 seconds as usual when I turned the key on...
 

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Like everyone stated, 43.5psi is LT1 pressure. You can still check the pressure even though the car won't start. Mine is around 45 PSI primed, not running. Hits ~42 when idling. I have a walbro 255lph pump also.

The invoice probably says 58psi by default since they thought it was a 98, and the dealer probably never even measured the actual pressure.

The float/gauge problem can only be a result from 1) wrong pump/float assembly, or 2) they broke it on install. There is no "tweaking" of the fuel pump float required if you simply swap out the fuel pump.
 

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already called the dealer
I think that is your problem. You've already had some discrepancies about the parts and even what work they've done. (That's not a slight on dealers- it's about your specific relationship with your shop.)

It really sounds like you've lost trust in your shop- trust that they can actually solve your problem. Might be time to find another shop.

Nothing wrong with getting a second opinion.
 

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Discussion Starter #13
I think that is your problem. You've already had some discrepancies about the parts and even what work they've done. (That's not a slight on dealers- it's about your specific relationship with your shop.)

It really sounds like you've lost trust in your shop- trust that they can actually solve your problem. Might be time to find another shop.

Nothing wrong with getting a second opinion.
Took it back to the original dealer that performed the work, since the work is supposed to be guaranteed (if I went somewhere else, I'd have to pay again for repairs, already paid enough for the fuel pump install). They seem very cooperative and want to help me out when I explained both of these issues to them.

Really had no time to shop around for another shop since the car needed a tow.
 

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Discussion Starter #15
You should pull your carpet up and see if they cut a hole in your floor to swap the pump!
No, they definitely did not cut a hole. I saw the tank on the floor when in the shop (and I guess they will be doing it once again). I have a feeling something came loose inside the tank which is why my car would not start up again.
 

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Discussion Starter #17
Defective fuel pump....looks like they're dropping it once again! I also asked them to fix the fuel gauge issue.

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Discussion Starter #18
Defective fuel pump....looks like they're dropping it once again! I also asked them to fix the fuel gauge issue.

Sent from my LG-P925 using AutoGuide.com App
They said one of the plastic pieces where the hose attaches to the pump broke off while in the tank.
 

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I hold 45psi on the dot. But it is a walboro pump
 
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