NEED HELP Fuel Pressure regulator location
- Thread starter Harut
- Start date
Mooseman
Moderator
Mooseman
Moderator
02-05: Regulator on the fuel rail with a return line. Filter on the output line near the tank.
06+: Regulator and filter in the fuel pump module in tank. No return line.
06+: Regulator and filter in the fuel pump module in tank. No return line.
Mooseman
Moderator
Mooseman
Moderator
And sometimes, mostly when engine was hot, car starts hardly. What is the problem? Fuel pump or what???
Mooseman
Moderator
You have to do some proper diagnosis work. Hook up a fuel pressure test gauge, check the pressure and see if it holds for any amount of time after turning it off. Fuel pressure specs are in the manual (link in my signature)
No, first of all I can't find the location of pressure regulator. And moderator say me that after 2006 they put regulator and fuel filter together with fuel pump. So now my car have hard starting when engine is hot.
Yes, I read the thread. I understand that you came in asking where the regulator is. My question was, what problem were you having that led you to think that you needed to find the fuel pressure regulator?
And how is that related to the hard starting when hot?
One thing that I'm thinking about is that the fuel system will also have a check valve in it to keep the fuel pressure up when the engine (and thus the fuel pump) shuts down. (I don't know the technical details on this year/model). If the check valve doesn't hold the pressure, then the fuel in the rail/fuel lines vaporizes. So on a hot start, the injectors are getting gas fumes rather than liquid gasoline. The result is a rough start.
If you want to check that, then next time on a hot start, turn the key to the run position - don't turn it all the way to where the engine cranks. Just to where all of the dash lights come on. Turn it back off. Then go to run position again (no crank). Do that about 5 times. Then turn the key all the way (to where it cranks/starts) and see if that gets it to start up smoothly. The goal is to basically prime the fuel system back up to pressure and purge the gas that has turned to fumes.
If that helps, then the answer doesn't change. The check valve is likely in the fuel pump, so it would need to be changed.
Of course, I still don't know what made you ask about the pressure regulator to begin with. And you can learn the same thing more accurately using a fuel pressure gauge (as mooseman suggested).
So I have 2002 trailblazer and 2006 envoy, both 4.2. In trailblazer pressure regulator is in the front of engine, but in envoy there are no regulator in the same front of the engine, I can't find. And that's why I ask where is the regulator? And if in 2002 model you can change the regulator for about $20 , now in 2006 model you will change whole fuel pump plus labor, and the same $20 work will cost you about $500. And there are no any relation between my first and second threads.
Mooseman
Moderator
On your 2006, the regulator is in the tank with the pump and filter. It's all in one unit. If any one of them fail, the whole thing has to be replaced although I have never seen the filter fail. Regulators do fail. Again, you have to do proper diagnostics before condemning it.
For future reference, people hang around here to try to help (and to goof off). It works out better for people who need help if they just make a separate thread for each question. Q1) Where is the FPR on XX year/model? Q2) I have a hard starting problem, especially when the truck is hot.
If you don't see a relation between the questions, then putting them in the same thread makes it harder for you to get help.
I'm not knocking you. Just saying that you'll get better / clearer help if you're more clear. So just trying to help you get help. (And still no one knows why you want to find the FPR on the '06).
To follow up with Mooseman's suggested diagnostics, I found it useful to construct an inexpensive gauge that fits the schrader valve on the fuel rail. You can leave it installed on the fuel rail for as long as you care to test fuel system operating and holding pressures.
The clearances surrounding the schrader valve are somewhat restricted, so a few extra bends in the gauge stem may be desirable. These were all Amazon sourced items totaling less than $30.
The clearances surrounding the schrader valve are somewhat restricted, so a few extra bends in the gauge stem may be desirable. These were all Amazon sourced items totaling less than $30.
So regarding my problem that my car have a hard starting when hot. I checked the fuel line pressure. When engine working there are constant pressure, but when I turn of the engine the pressure going down to zero. This means the pressure regulator is dead( there are no leaks from fuel line). But since 2005 to 2009 envoy and trailblazer lineup change the location of regulator from front of engine to the inside of fuel tank, instead of $20 I buy $300 fuel pump plus $300 labor and replace it. Now everything is ok with car starting, it's starts in cold and in hot wery well.
flyboy2610
Member