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2003 DeVille DTS
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228 Posts
Discussion Starter #1
I ran out of gas, and foolishly cranked it a little too long, trying to squeeze another hundred yards out of it. (I did manage to get to a safe place)

Since then, the car idles horribly, near stall, and accelerates roughly under medium or heavy load. Still seems normal at cruising speeds.

I figure I've damaged the fuel pump, but then I also figure a fuel pump would either simply work, or not work. It starts every time no problem, it just seems like it's going to drop dead at any moment. Code P1599 near stall shows up, and also a new message "check fuel gage".

SO, can a fuel pump be "near" failure? It idled a little roughly before I ran out of gas, but not nearly as rough as it does now. I figured the previous was fuel pressure regulator, but haven't looked into it.
What's the best way to tell for sure?

Pump is about $300 with shipping from GMpartsdirect, and the instructions call for a couple of special tools, but otherwise seem pretty easy. If I replace the pump, should I do the regulator too? 85k miles.

Thanks to anyone who reads all this and replies!
KD in NH
 

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108 Posts
If you ran it dry then you sucked any "gunk" that may have accumulated in the bottom of the tank through the pump and into the filter. I'd probably change the fuel filter first and see if that offers any improvement.

Steve
 

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1999 STS - diamond white
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5,229 Posts
Yup, I agree with Steve. You either sucked up debris or water. Let us know how it comes out. Pun intended.
 

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Cadillac Owners Connoisseur
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1,164 Posts
It's also possible that the fuel pump has burned up AND there is junk stuck to the screen. The pump runs while you're cranking it, and if it's running dry, it has no cooling may have overheated. You can check the fuel pressure, but I'm willing to bet it's low. Can you hear it when you turn the ignition on? It should run for about 2 seconds. If the thing got hot enough, it could have melted the wiring above the fuel tank, and that could cause the fuel gauge message you have. Someone else had that problem with a bad fuel pump a while back and I remember reading about it here. If you use the Search feature above, look for fuel pump melted harness or similar stuff.
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,778 Posts
Pull the vacuum hose off the FPR while idling and look for a leak at the nipple. R & R it if it is leaking.

A fuel pump can die in many ways. I have seen them die in their sleep to a slow agonizing intermitten failure. Check the fuel pressure, ignition on, engine off. Check it while cranking and while idling as well as driving. Fuel pressure should remain "relatively" steady. There will be some fluctuation with throttle but it should be only a few PSI I believe.
 

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2003 DeVille DTS
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228 Posts
Discussion Starter #6
Thanks for the replies folks.

I changed the filter, it helped a lot, but there's still a problem. I'll probably change the FPR as I've always suspected a problem there anyways, rough idle etc.

But I think the main problem is now gunk at the pump itself, or pump 'failure'. I figure if I'm gonna open up the tank to clean the pump filter or whatever, I might as well put in a new pump. Not cheap, but worth the peace of mind I think.

So in the end, I will have replaced pump, fpr, and filter. About the wiring harness, can I see it from the access panel, or do I need to drop the tank?

Next time I'll pay attention when the display says 'low range'.

Thanks again
KD in NH
 

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94 ETC,97 STS
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3,531 Posts
The harness in the tank can deteriorate. Inspect it when you pull the pump. The filter in the tank may be clogged. It is inexpensive but you have to pull the pump to replace it.

You may want to check the fuel pressure before and after.

Especially when running as low flow may look good at idle but drop pressure quickly as rpm's increase.
 

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2003 DeVille DTS
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228 Posts
Discussion Starter #8
Well, I've gotten to the filter and fpr. Before I crack the gas tank open, is there anything else to look at?

It almost stalls at especially at idle, especially when cold. At highway speeds it struggles though it never feels like it will shut down.
Definitlely seems like more than an injector or ignition problem, but what the hell do I know? $300 plus a day's labor on the fuel pump is gonna suck if that's not it, amkes $50 so far on filter/fpr a drop in the bucket.

One last thing, the book calls for both the fuel pressure gauge, and also some kind of tool to pull the pump. Do I really need them?

Thanks
KD
 

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2003 DeVille DTS
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228 Posts
Discussion Starter #9
Well I've ordered the fuel pump. The pressure gauge seems easy enough, but wrench J 39765 is an odd looking duck. Any I've found online are ~ $100. J 39765A is about $7, but doesn't appear to be the same. Is what I need available to rent anywhere?
This repair seems easy enough, for want of the right tools! Ideas, anyone?

Thanks
KD in NH
 

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Super Moderator
White Diamond '03 DHS (with DTS floor shift)
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86,778 Posts
Before you go through all this, get a guage on the rail and check your fuel pressure.
I am not sure what kind of tool you need but, many times GM has a "special tool" that a screwdriver will take the place of. The last time I pulled a pump, all I needed was a screwdriver and a hammer to tap the cam lock ring loose. Of coarse there was a "special tool" for the job. Maybe someone who has done one recently will chime in.
 
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