If I were to guess and your info is ACCURATE,

Blocked fuel filter
OR
Leak between fuel pump and the sender- holder so fuel isnt building any pressure .
OR
Regulator is jammed open so the fuel is being returned from the rails before any pressure is built up.

Get a pressure gauge on the rail.

Verify the pressure or lack of it

I would begin by removing the return off the regulator blocking it and momentarily activating the pump.
If it pins the pressure guage then the regulator is the culprit.
If no pressure and you are positive ( back to your info) the pump is running, you either have the big leak inside the tank or the filter is plugged solid.

 

If I were to guess and your info is ACCURATE,

Blocked fuel filter
OR
Leak between fuel pump and the sender- holder so fuel isnt building any pressure .
OR
Regulator is jammed open so the fuel is being returned from the rails before any pressure is built up.

Get a pressure gauge on the rail.

Verify the pressure or lack of it

I would begin by removing the return off the regulator blocking it and momentarily activating the pump.
If it pins the pressure guage then the regulator is the culprit.
If no pressure and you are positive ( back to your info) the pump is running, you either have the big leak inside the tank or the filter is plugged solid.

The Fuel is getting to the engine. I captured it in the second half of the video I recorded and added a link to.

 

No fuel pressure at schrader valve either means that the fuel filter is completely blocked or the fuel pump assembly is not doing what you expect.

You mention Fuel Pump Working - How do you know this?

Replace $12 filter if you're unsure, but probably not the case

Fuel pump may not be pumping
Tank may be out/low on gas
Tube coming out of fuel pump may be broken/split/disconnected

 

Fuel pump is operational and the line is in tact. I disconnected the inlet line and recorded fuel coming out at the fuel rail.

 

My apologies - I didn't watch the video initially.

I'd start with what 95wagon mentioned and look at the fuel pressure regulator.

With a fuel pressure gauge on the shrader valve, Pinch/block the return line and see if it builds fuel pressure.

 

I took the battery to Autozone to get charged. I will work on the Regulator in the AM.

 

If you haven't get a gauge on it.

Fuel running out of the hose at no pressure doesn't nessasarily mean there isnt a leak at the pump ,
It could freely run out the line at the front with no restriction but stop flowing , pissing away in the tank, as soon as you ask the system to build pressure.

Or the regulator is dumping the fuel back to the tank not allowing the pressure to rise in the rails

 

If you haven't get a gauge on it.

Fuel running out of the hose at no pressure doesn't nessasarily mean there isnt a leak at the pump ,
It could freely run out the line at the front with no restriction but stop flowing , pissing away in the tank, as soon as you ask the system to build pressure.

Or the regulator is dumping the fuel back to the tank not allowing the pressure to rise in the rails

With the return hose disconnected there was no fuel coming out to go back to the tank. It seems like the fuel is getting stuck at the injectors. Wouldnt the fuel injectors send enough gas to an engine and start it even if it rev'd low?

 

please always use a fuel pressure gauge. Pumping gas into the engine compartment like that is extremely risky.

Can you post a video with your phone directly below the gas tank while you turn the ignition on? I want to hear how the fuel pump sounds.

I have learned the hard way on these cars and others that just because you can hear a fuel pump running doesn’t mean it’s producing usable pressure.

 

I added the video you requested to my iG story.

https://instagram.com/boprestoration?igshid=ZmZhODViOGI=

 

Got it. Fuel pump sounds healthy but it's not loading up (RPMs start out high but then they should drop as pressure builds). Based on that, I don't think it's the fuel filter clogged. I'd drop the tank and verify that there's not a leak between the pump and the top of the sending unit. If the sending unit has been replaced, there's a known issue that the newer sending units used a rubber hose not rated for 43psi, and it splits after 300 miles. You'll get exactly the behavior you're seeing here.

If you drop the tank and find a ruptured hose, this is the part you may need: Goodies Speed 75114.

 

you do the fuel pressure gauge ... the correct pressure is 45-47 psi to turn the key on no engine cranking ..
the fuel pressure is dropping around 37psi no engine running ....
also if the fuel pressure is using the hose in the container your not gone to do the pressure ....
my 96 Impala changed the fuel pump ,,,, inspected it of the electrical contacts cleaned it .. the fuel pump was the positive contact and the harness connection then I changed the connector .. the fuel pump motor was the positive brush and the brush was worn out ....

 

Are you saying that the regulator was moved to the pump? Should the fuel be coming out as more of a spray?

 

@arnoldsmind no. Follow my instructions above; disconnect the fuel lines and filler neck and drop the tank.

 

I'm headed to Harbor Freight to get a Fuel Pressure gauge. If there is no pressure what is the next step? If it was holding pressure shouldnt fuel come out of the schrader valve?

 

the GM valve is the fuel pressure of the schrader valve on the intake manifold ,, .harbor freight uses the hose and the connector of the GM pressure gauges .. the shut off valves around the gauge ..
...then the fuel pressures are many other connectors of different companies ..

Fuel Injection Pump Tester

Amazing deals on this Fuel Injection Pump Tester at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

Think we kinda covered this .
If you are not building pressure , first disconnect the return line off the regulator .
If fuel is coming out and you are not building pressure the regulator is bunned.
The regulator should be closed at anything below the rated pressure.


IF nothing comes out of the regulator and no pressure is being built up , the likely culprit is a leak inside the tank.

BTW you do not need to crank or either start the engine.
Next to the AC accumulator you will find a single loose red wire with a terminal on it .
If you feed it 12volts the pump will run.

 

You posted as I was typing.
I beleive there is a pressure threshold below which the injector will not pass fuel .

 

Purchasing is not expensive, but for as many times as you'll use one most parts retailers will 'loan' (with deposit) a complete setup. I grabbed one from AutoZone last month to check the Sister In Law's SUV. Their kit turned out brand new and with every imaginable adapter and fitting. And yes, it was the pump and all I had to do was lift the back seat to expose the hatch.

 

What am I looking for that would differentiate between the problem being the Fuel Pump vs Something else. My Vice Grip Garage school of automotive technology license taught me that if the Schrader is dry there is no pressure and the Fuel Pump is out. But that’s not the case here. A leak in the tank doesn’tThere's fuel delivery. The leak would have to be in the fuel line, and that would show as a fuel on the floor. Full transparency, I’m dreading having to drop the tank, It’s half full. I want to explore all options before changing out a working fuel pump and being back at square 1.

 

Last time for me ,

If the line INSIDE the tank is loose or has a split, fuel will still run out the front when there is no resistance ( as in an open line )



Ask it to build system pressure and the fuel chooses the easy route and pushes through the split and doesn't flow forward anymore.

A really lame pump can exhibit similar symptoms.

Can flow fuel at zero pressure , will flow nothing when asked to build pressure.

Rarely bad grounds can show similar simptoms but I doubt it here.

As in bad ground , the current finds a new route to ground like, through a lamp filiment.

As it to make pressure , the draw goes up and the " new path" will not carry the load and the pump stops.

Good luck with your search.

 

Last time for me ,

If the line INSIDE the tank is loose or has a split, fuel will still run out the front when there is no resistance ( as in an open line )



Ask it to build system pressure and the fuel chooses the easy route and pushes through the split and doesn't flow forward anymore.

A really lame pump can exhibit similar symptoms.

Can flow fuel at zero pressure , will flow nothing when asked to build pressure.

Rarely bad grounds can show similar simptoms but I doubt it here.

As in bad ground , the current finds a new route to ground like, through a lamp filiment.

As it to make pressure , the draw goes up and the " new path" will not carry the load and the pump stops.

Good luck with your search.

No pressure confirmed with the gauge. Here is a pic of the gas.

 

Agree with @95wagon. You're gonna have to drop the tank.

One trick to empty the tank on these cars is to disconnect the fuel filter connection, put a hose over that line and aim the hose into a gas can. There's a red jumper next to the underhood fusebox, put 12V on that and it'll turn the fuel pump on. Use that to pump the tank out.

 

my fuel pump was burning the 12 volt connector LOL then I replaced the harness connector and replaced the GM fuel pump .....

 

Please post the outcome of your case. I am having similar issues. Thank you!

 

Will do. Fuel pressure gauge arrives today

 

Or you could just drop the tank already... The pressure gauge is not going to tell you anything you don't already know.

 

I will. I will work on finding that fuel pump trigger wire. I will go through all steps given by forum member. I will take all the advice I asked for. I will get over my PTSD from dropping a full tank. Ended up snapping a line on my last install.

 

I'm closer to swapping in a carb and intake like this guy.

 

Here is a video of the inlet hose running. I blew through the same hose and was able to blow through, I just looked like a trumpet player.

Login • Instagram

Welcome back to Instagram. Sign in to check out what your friends, family & interests have been capturing & sharing around the world.

instagram.com

 

The carb won’t like 0 fuel pressure either.

 

my 1984 camaro berlinetta 7-10 psi...gasoline manual .of the engine fuel pump ....not electrical motor..
305 cu in 4 carb .. 1984 to today ! runs good ..

 

You've confirmed that the reason the engine doesn't run is that fuel is not getting through the injectors into the engine - Good

This means that either the injectors are not being told to open by the ECU or that there isn't enough fuel pressure to open the injectors when the ECU commands them open.
The injectors need a minimum fuel pressure to open - if there isn't enough pressure, they won't open just a little and the engine runs at low power when the ECU commands them open - they won't open at all. This is an "AND" scenario - you need the fuel injector commanded open by the ECU - AND - more than 45psi fuel pressure for the injector to open and deliver fuel to the engine.

Injector commanded by the ECU and less than 45 psi fuel pressure = no fuel in the engine
More than 45 psi fuel pressure, but no command from the ECU = no fuel in the engine
Injector commanded by the ECU and 45 psi of fuel pressure = fuel in the engine and it'll run

You mentioned that you have a fuel pressure gauge - what does it read with the key on/engine off? You can't tell anything by looking at the port, you need a pressure gauge to tell what the fuel pressure is.

 

You've confirmed that the reason the engine doesn't run is that fuel is not getting through the injectors into the engine - Good

This means that either the injectors are not being told to open by the ECU or that there isn't enough fuel pressure to open the injectors when the ECU commands them open.
The injectors need a minimum fuel pressure to open - if there isn't enough pressure, they won't open just a little and the engine runs at low power when the ECU commands them open - they won't open at all. This is an "AND" scenario - you need the fuel injector commanded open by the ECU - AND - more than 45psi fuel pressure for the injector to open and deliver fuel to the engine.

Injector commanded by the ECU and less than 45 psi fuel pressure = no fuel in the engine
More than 45 psi fuel pressure, but no command from the ECU = no fuel in the engine
Injector commanded by the ECU and 45 psi of fuel pressure = fuel in the engine and it'll run

You mentioned that you have a fuel pressure gauge - what does it read with the key on/engine off? You can't tell anything by looking at the port, you need a pressure gauge to tell what the fuel pressure is.

The gauge doesn't move at all. Under any circumstances.

 

Got it - Next step is to remove the return line and see if there is any fuel coming out of the engine going back to tank.

If so, time to check the fuel pressure regulator.
If not, it's time to drop the tank and pull the sender/pickup/pump assembly.

You mentioned that the tank is ~1/2 full - You can drain it by disconnecting the line to the engine and running that into a container similar to what you showed in the last video. Over on the right (passenger) inner fender up by/behind the fuse box, there is a single red wire hanging out about 4-6" with a black female electrical terminal on it. With the key off, use a jumper wire and connect this red wire to the positive side of the battery (or the aux post on the fuse box) and it will power the fuel pump directly.

Drop the tank as noted by others in earlier posts. With it mostly empty, it's really not that bad of a job. If things are rusty, start spraying them down with penetrating oil regularly before you start.

You questioned how the system inside the tank could be bad if there is fuel coming out up at the engine.
Imagine a garden hose connected to your house, stretched out straight, no kinks, no spray nozzle, just an open end. You turn the handle on the faucet so water flows through the hose (same as turning the key on and powering the fuel pump). Water (fuel) comes out the other end - no problem, just like the test you have run on your car with the fuel line disconnected.

Now, in the middle of the hose, take a knife and cut a foot long slit along the length of the hose and repeat the test - water (fuel) comes out the end more/less the same as it did before, right? But if you put a nozzle or your thumb on the end of the hose, it won't build any pressure because all the water (fuel) goes out the slit. This is one scenario of what may be going on inside your fuel tank.

The other possible option is an issue with the fuel pump itself - Either electrical in nature (there's voltage to the pump, but not the ability to carry a load and therefore build pressure) or the pump itself has started to fail mechanically where it can push some fuel, but not build pressure.

 

Got it - Next step is to remove the return line and see if there is any fuel coming out of the engine going back to tank.

If so, time to check the fuel pressure regulator.
If not, it's time to drop the tank and pull the sender/pickup/pump assembly.

You mentioned that the tank is ~1/2 full - You can drain it by disconnecting the line to the engine and running that into a container similar to what you showed in the last video. Over on the right (passenger) inner fender up by/behind the fuse box, there is a single red wire hanging out about 4-6" with a black female electrical terminal on it. With the key off, use a jumper wire and connect this red wire to the positive side of the battery (or the aux post on the fuse box) and it will power the fuel pump directly.

Drop the tank as noted by others in earlier posts. With it mostly empty, it's really not that bad of a job. If things are rusty, start spraying them down with penetrating oil regularly before you start.

You questioned how the system inside the tank could be bad if there is fuel coming out up at the engine.
Imagine a garden hose connected to your house, stretched out straight, no kinks, no spray nozzle, just an open end. You turn the handle on the faucet so water flows through the hose (same as turning the key on and powering the fuel pump). Water (fuel) comes out the other end - no problem, just like the test you have run on your car with the fuel line disconnected.

Now, in the middle of the hose, take a knife and cut a foot long slit along the length of the hose and repeat the test - water (fuel) comes out the end more/less the same as it did before, right? But if you put a nozzle or your thumb on the end of the hose, it won't build any pressure because all the water (fuel) goes out the slit. This is one scenario of what may be going on inside your fuel tank.

The other possible option is an issue with the fuel pump itself - Either electrical in nature (there's voltage to the pump, but not the ability to carry a load and therefore build pressure) or the pump itself has started to fail mechanically where it can push some fuel, but not build pressure.

that dirty gasoline is a mess yellow dark color ...then flush out the gas .. drop the tank inspect the fuel pump and the electrical connectors .. also the fuel pump filter screen ..

 

Drop the tank. Upgrade the fuel pump (walbro 255lph) and add adjustable regulator (accel or aeromotive). Set to 45psi. My car just ran like schitt when my OEM injectors went bad. If you are replacing injectors too,, don’t go cheap and replace them all (no hecho in China - unless Delco (ha!)

also, though it doesn’t sound like it in the video, but you may want review intake side for leaks or loose connectors. Loose MAF and MAP will also cause car to turn on and right back off.

 

I will get after it on Friday.

 

My vote, in agreement with others, is an issue in the tank. Unfortunately.

For example, this is a fun failure mode to sort out. This allowed a fuel trickle but wouldn't build pressure. And at first glance you don't see the split. If yours has a black rubber hose like this, forget it. They fail readily. The better design is the plastic corrugated flex hose. But even those can fail too, just much less often. Also check the pump/sender interface. Or just replace the whole sender and pump.

 

many fix it to change the rubber hose in the gas tank LOL !!!!!!!!!!!!!!!!! is a breakdown ..
plastic hose and is the OEM .....

 

Got it running. I bought the fuel pump, but didn't install it. I put a couple bottle of octane booster in it over the weekend and like magic. We have a runner.