Loss of fuel pressure

[Rogerb3116]

My daughter has a 2006 Buick Allure with a 3.8. The car is in excellent shape with only 80,000 miles on it. If it sets overnight, it takes about 10 seconds to start. Any other time it starts immediately. If you turn the key on and wait 10 seconds, it starts immediately. It appears that it is losing fuel pressure when it sits for a long time. There are so many things it could be, fuel pump, leaking injectors, fuel filter, rusted fuel lines, etc. I am looking for some advice on what you think it most likely is to give me a place to start. Thanks for your help. Roger

 

[Chris142]

My guess I s that there is a check valve at the bottom and,part of the pump assembly that's bad. If it was an injector it would run rough at first.

 

[Warstud]

Sounds like a bad fuel pressure regulator .

 

[Lubener]

Sounds like a bad fuel pressure regulator .

Only if fuel leaks out the vacuum nipple which means the diaphram has ruptured.

 

[Lubener]

My daughter has a 2006 Buick Allure with a 3.8. The car is in excellent shape with only 80,000 miles on it. If it sets overnight, it takes about 10 seconds to start. Any other time it starts immediately. If you turn the key on and wait 10 seconds, it starts immediately. It appears that it is losing fuel pressure when it sits for a long time. There are so many things it could be, fuel pump, leaking injectors, fuel filter, rusted fuel lines, etc. I am looking for some advice on what you think it most likely is to give me a place to start. Thanks for your help. Roger

Connect a fuel pressure gauge to verify either low fuel pressure or bleed down is happening which would require a little troubleshooting..A fuel filter would be a cheap item to check and should be changed with a new pump anyway. I had a Buick 3.8 series 2 behave exactly like yours and it was a weak pump delivering lower than spec fuel pressure.

 

[Rogerb3116]

Sounds like a bad fuel pressure regulator .

Where is that?

 

[Rogerb3116]

Connect a fuel pressure gauge to verify either low fuel pressure or bleed down is happening which would require a little troubleshooting..A fuel filter would be a cheap item to check and should be changed with a new pump anyway. I had a Buick 3.8 series 2 behave exactly like yours and it was a weak pump delivering lower than spec fuel pressure.

The fuel pump was my first guess

 

[JavierH19]

Most likely the fuel pressure regulator which is like a little diaphragm on the fuel rail to prevent the pressure from bleeding back. Happened to my truck after 328k on the original. Cheap simple fix.

 

[Warstud]

Where is that?

 

[Rogerb3116]

Thank you. That looks easy

 

[Lubener]

Thank you. That looks easy

Don't assume it is bad. Pull the vacuum line off and cycle the key a few times to see if fuel squirts out. Its purpose is to keep the pressure from going too high. In a properly functioning system, pulling the vacuum line off while the engine is running will cause the fuel pressure to go up. If it's not leaking fuel out the vacuum port, look elsewhere for the cause of your problem or you are just wasting your time and money..

 

[Rogerb3116]

Thanks. I will let you know