Engine won't start

When you park on a hill the fuel seems to run back into the tank. I have replaced the fuel cap thinking that it didnt seal very well, but thats not it

Is the fuel pump in the tank as well?

Engine Performance problem
2000 Oldsmobile Bravada 6 cyl Four Wheel Drive Automatic 137000 miles

Our Bravada works fine in warm weather. But once temp falls under 20 degrees at night it wont start until it warms back up above 30 degrees or so.

I recently replaced a fuel pump on my bravada. My gas tank has a leak so I replaced the tank with a used one from a junk yard.

When lowering the leaky tank it slipped and fell breaking a post from my fuel pump. I decided to use the fuel pump that came with the tank to save money. TUrning the key, I can hear the pump kicking on and off but not starting the car. Now my car kicks a P0452 code. I notice my pressure sensor could use replacing. But would that cause it not to start?

ALSO I noticed in the bottom of the used tank I got a little bulb looking thing rolling around, I removed it. I assume it connects to the vent on the gas tank. WOULD that be a reason for it not to start? Lastly I read on another post where someone was having my issue and a response was is your does your battery constantly die. Could the two be related? Even jumping my car for a half hour, if the cables are off it dies very fast. Any help appreciated.

I assume it COULD be a bad pump but hoping not. Thanks in advance

The P0452 is a low fuel tank pressure code. If you look under the hood, you should be able to find a pressure test port near the center of the intake where the fuel lines enter. It should look like a valve stem cap on a tire. If you can borrow a fuel pressure gauge and attach it here, you will be able to take a manual pressure reading. I will have to look up the specs for sure, but I believe it should be between 50 and 60 psi. If fuel pressure is too low the vehicle will not start. The injectors on the 4.3 vortec are pressure activated and wont open even if the fuel pressure is one or two psi lower than spec. Considering that its a used fuel pump on what already is a sensitive fuel system, I would verify pressure before wasting time on anyother tests.

When checking the pressure should the vehicle be in the on position or key off

Key on cranking the engine so that it has enough time to build fuel pressure.

No I didnt. Unfortunately it could be days before I can do something on a fuel pressure gage. I dont have one, and the only place that does loan out charges up front for them first so it will be a couple days before I get paid to rent a gage. Also what is that little thing I was describing in the tank? I was bulb shaped

I cannot get my 2000 Bravada to start. At first I thought it was the distributor, since after it rains mine can be difficult, and usually requires drying with a low-power heat gun. When this did not work I listened for the fuel pump, which did come on when I put the key in, and both the exhaust and engine (by way of air intake port) smelled like gasoline, leading me to believe it was an electrical, not fuel, problem. I tested the volts at the distributor cap and saw that there was no power reaching it. The rest of the powered things on my car work fine (radio, windows, power seats etc.) So it seemed strange that there was no spark plug power. The starter sounded fine, so I guess something is grounding out somewhere along the way, or I have a bad coil. Any advice on what might cause this?

Hard to say what the bulb shaped object is. It is most likeley part of a broken vent or pressure control valve, but the possibilities are endless without seeing the object or knowing the dimensions of it.

I am wondering what the result was ofr flyfisher65"s question above. I am having the same issue with my 2000 Bravada. When it rains, it doesn't want to start. I was stranded at work on Christmas Eve when the truck decided it wasn't going to start for me. No rain at that point. It made a horrible clicking noise which made me wonder if the starter is bad. I'm in the process of replacing the starter now. All electronics on the truck worked when I tried starting the truck so I know it isn't a battery issue. Help! Also, mine has no heat. The thermostat has been replaced and it doesn't have coolant. The hoses under the hood get hot, but there is no hot air coming into the truck. Only cold air. I'm at my wits end with this truck. And I'm a girl!