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Fuel Pressure Regulator location?


tmpafford

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Where can I find the fuel pressure regulator? I am having problems with starting my 97 STS. I have to let it crank for about 4-5 seconds and sometimes I have to give it a little gas to get running. I don't think there are any codes showing up, but I have not checked them lately. I also have a little stutter to the purr of the engine (I feel more than I her a purrrrrrrdrrrrrrrrdrrdrrrrrrrrrrdrrrrrrr). I am assuming that these are all related to the FPR.

I will be taking the car in to get the fuel rail replaced under the recall, but I would rather replace the regulator myself than have the dealer do it.

Where can I find it and what does it look like?

Mac

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It is a small round canister type thing located on the fuel rail. I believe it is on the rear bank side. It is identifyable by the vacuum hose plugged in to the top of it. Check to see if it is bad by removing the vacuum hose while the engine is running and look for fuel leaking out of the nipple. A bad FPR will usually cause hard "hot" start situations. If yours is a cold start problem it may be a weak (failing) fuel pump. BTW, the FPR has to be removed from the old fuel rail and reinstalled in the new one so if it needs to be replaced there should be NO charge for the installation at the dealer, only the cost of the FPR.

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...so if it needs to be replaced there should be NO charge for the installation at the dealer, only the cost of the FPR.

You have never dealt with the dealers in Houston. They take the labor costs right out of the book. It does not matter that they have already charged the same labor for another part.

I had that happen when I was getting my carpet replaced due to high water. I thought that since the center console was going to be removed, I could get them to fix the AC fan for the rear seats and fix the ash tray lid. They quoted me the same labor to remove the console twice! I said that I was already paying for the console to be removed, why should I pay it two more times? I was told that that is how their pricing system was set up. Bunch of crooks!

I could have them replace the FPR when I get the fuel rail replaced under the recall, but I will have to pay for the labor to have the fuel rail pulled and replaced. Unless they have changed their system in the last year or so.

I will try the vacuum hose test. I have had hot start problems also. Twice in the last year I have been unable to get the car to start after shutting it down for a few seconds. I just thought I had a small "vapor lock" that was cleared by pumping the gas pedal while cranking.

How could I test the fuel pressure? Or should I just pay the dealer to look at it while they do the fuel rail? I had the FPR replace about three years ago.

Thanks

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If there isn't any fuel leaking from the FPR nipple while the vacuum hose is disconnected and the engine is idling, the FPR is good. A stuck/leaking injector may be causing the hot start problem.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Not only have I not dealt with dealers in Houston, I rarely deal with dealers, period. I do most of my own wrenching. I would call another dealer and see if they area going to double charge you. This guy is obviously a crook.

If you have a fuel pressure guage just screw it on the fitting on the fuel rail. It looks just like a tire valve. I think the pressure should be about 45-50 psi. It may drop slightly during cranking but if I recall Guru's previous post correctly, it should not drop drasticly.

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Ya, there were three things that came to mind. Fuel pump, Fuel Pressure Regulator or Injectors.

I could not see injectors being the cause of a long crank being required for startup but they might be the cause of the stutter at idle.

The fuel pump could be the cause of the low fuel pressure at startup, but wouldn't I have problems with maintaining speed if it is that bad?

Fuel Pressure Regualtor seemed the most likely thing. I assumed that is was some sort of electrical pressure sensor that was fouled, but it sounds like it is a diaphragm type pressure sensor. If there is a small hole in the diaphragm it would slowly leak out the fuel pressure while parked. This would explain the long cranking time required. The engine vacuum would then have to overcome the small amounts of fuel being on the wrong side of the diaphragm before the suction would affect the diaphragm.

How easy is it to get to the vacuum hose on the FPR? Do I have to take the decorative cover off the intake or can I just pop the hood and pull off the hose?

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A leaky injector will usually aid in cold starts as it will richen the mixture somewhat like a choke on a carberated engine but likewise will be detrimental to hot starts as will the FPR.

Yes, you'll have to remove the "beauty" cover and you'll see the FPR on the rear bank fuel rail. It is a diaphram with fuel pressure on one side and engine vacuum on the other. If it has a leak, the pressure will leak down and the fuel will go into the manifold aiding in a cold start as mentioned above.

A fuel pump can go bad in many ways. I have had one where the engine would just fall flat on it's face at WOT but ran fine otherwise even at highway speeds, and that was only after running for about :15-:20 minutes ('92 Deville). I had another ('95 Blazer) that caused hard start situation but ran fine otherwise. And yet a third ('93 Blazer) that would just kill the engine, then restart and run fine. A girl I work with drove in one day last winter just fine, then the car refused to start to go home. I diagnosed it as a fuel pump and sure enough when she had it towed in it was the pump. It had died in it's sleep.

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Ya, there were three things that came to mind. Fuel pump, Fuel Pressure Regulator or Injectors.

I could not see injectors being the cause of a long crank being required for startup but they might be the cause of the stutter at idle.

The fuel pump could be the cause of the low fuel pressure at startup, but wouldn't I have problems with maintaining speed if it is that bad?

Fuel Pressure Regualtor seemed the most likely thing. I assumed that is was some sort of electrical pressure sensor that was fouled, but it sounds like it is a diaphragm type pressure sensor. If there is a small hole in the diaphragm it would slowly leak out the fuel pressure while parked. This would explain the long cranking time required. The engine vacuum would then have to overcome the small amounts of fuel being on the wrong side of the diaphragm before the suction would affect the diaphragm.

How easy is it to get to the vacuum hose on the FPR? Do I have to take the decorative cover off the intake or can I just pop the hood and pull off the hose?

I am also from the Houston area, and just recently went thru the same trouble with my Fpr. If you need help ckecking it out let me know as I just did mine 2 months ago. Also if you plan on having the fuel rail done, I would highly recommend David Taylor Cadillac, they even cleaned my throttle body at no charge.

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Way to go Mark. Name names. Give the good guys a plug and the bad guys a black eye.

Larry, my car has only been to the dealer once in ten years and that was for the new fuel rail. I don't plan on making it a habbit. My experience at that dealership was good as they let me watch them change the rail.

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Way to go Mark. Name names. Give the good guys a plug and the bad guys a black eye.

Larry, my car has only been to the dealer once in ten years and that was for the new fuel rail. I don't plan on making it a habbit. My experience at that dealership was good as they let me watch them change the rail.

WOW, letting you watch is almost unheard of. We are alot alike. I think mine has been in 2 or 3 times under warranty but the fuel rail is the first time since then. Non the less, the good ones deserve a plug as a lot of people reading this board may not do their own wrenching.

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...I would highly recommend David Taylor Cadillac, they even cleaned my throttle body at no charge.

That is where I bought my car. Great Dealership! However they are the farthest from my home and office now. The other two (Tom Peacock and McGinnis) leave you feeling like something was wrong, but you just can't put your finger on it. I have never been cheated by the other two or felt like they did an inferior job. Just the opposite. I think they do good work, but I just left with that little nagging feeling. Could this have been better if I had gone to Taylor?

Thanks guys! I will do the tests this weekend.

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