94 sc 400. after pressure test i re placed the fuel pump and filter, both original!!! because a progressive drivability issue. Start and drive cold its OK, but as soon as closed loop, spit sputter stall low idle ect.... so far the fuel pressure before and after regulator is the only thing that tested bad. New pump, filter, wont start at all now. 12v test at pump, no power. what the FFF did i miss on the pump install.

P0087 is Fuel Rail/System Pressure - Too Low, indicating a fuel system problem.

What causes the P0087 code?

• The most common cause is a clogged fuel screen or filter
• A failing fuel pump
• A restricted fuel line
• Improperly reading fuel pressure sensor will set P0087 as well

What are the symptoms of the P087 code?

• Check Engine Light illuminated on the dashboard
• Vehicle may run poorly
• Loss of engine power, noticed during acceleration
• Engine misfire
• Vehicle may stop running

How does a mechanic diagnose the P0087 code?

• A mechanic will begin by using a scan tool to read any codes present.
• Once these codes are identified and the freeze frame information looked at for each code they will be cleared.
• Next a road test will be performed under similar conditions as the freeze frame data.
• If the Check Engine Light comes on a visual inspection of the fuel tank, fuel lines, and fuel filter will be performed.
• Manual fuel pressure readings will then be taken at the fuel rail and compared to specifications. A scan tool will then be used to compare manual readings to what the ECM sees.
• Lastly, the fuel pump will be tested.

Common mistakes when diagnosing the P0087 code

• Mistakes are made when steps are skipped or not completed.
• Though the most common cause is a clogged fuel filter this will not fix all vehicles and circumstances.
• It is important to follow the steps so unnecessary repairs are not performed wasting time and money.

How serious is the P0087 code?

P0087 can lead to serious drivability issues. If the vehicle starts running poorly and having misfires it must be diagnosed ASAP to ensure safe driving. If the fuel pump is failing or the fuel filter becomes completely clogged, this may cause the engine to die while driving resulting in serious issues for the driver. A qualified mechanic should be contacted and repairs should be done to get the vehicle safely back onto the road.

What repairs can fix the P0087 code?

• Replacing the fuel filter or screen
• Replacing kinked fuel lines
• Removing and replacing the fuel pump
• Replacing a faulty fuel pressure sensor

Additional comments for consideration regarding the P0087 code

A manual fuel pressure tester is needed to diagnose P0087. This allows us to check fuel pressure at the fuel rail and then use the scan tool to check what the fuel pressure sensor is reading. Both of these readings are needed to test the fuel pressure sensor.
An advanced scanner is also needed to monitor fuel pressure sensor data.
Some vehicles may not be equipped with an external fuel filter. These vehicles will only be equipped with the fuel screen that is attached to the fuel pump. These are generally replaced as one unit since the gas tank must be removed from the vehicle in most cases.
Care should be taken when test driving a vehicle with a failing fuel pump. If the fuel pump is failing it may do so when driving causing the vehicle to die while driving or not be able to be restarted.

Did you do fuel system testing when hot ? Fuel pressure and flow testing ? Did you view scan data ? Does it have spark when it won't start an run ?
Taking the vehicle to a qualified drivability tech maybe the best thing to do. What are the fuel trims at , short term an long term ,or the O2 sensor's switching , what data is the PCM seeing for the mass air flow sensor , for that matter all the sensors ? ECT , TPS , MAP
048 Engine Hard to Start or No Start Scan Data for Starting Problems
002 Fuel System Tests Start Here

There is no emergency fuel shut off switch on your vehicle , ford vehicles have one , called inertia fuel shut off .
If they replaced the fuel pump an your still having the same problem i would check fuel pump relay and the electrical circuit for the fuel pump . Voltage drop testing the electrical circuit will show problems most people would attribut to a bad fuel pump , but it's not the pump.
Testing Electric Fuel Pump Problems with Voltage Drop Test
Fuel pump electrical circuit diagnosis no fuel pressure testing GM

I would take it back an tell them to fix it correctly . or demand your money back .

check fuel pressure possible fuel pump issue

It can be caused by a bad crankshaft sensor, plugged fuel filter, or clogged tank internal filter, as well as a failing fuel pump. Although the crankshaft sensor may not seem to be related to the fuel group, fuel demand is anticipated by counting the RPM's which is the crankshaft sensors job.
Now "hard to start" issues can be fuel pump pressure problems. But do not forget the "cold start routine" which requires a temperature sensor to set the engine management system for a cold start. It becomes less of a factor when the engine is warm but would not be responsible for low fuel pressure.
A simple test for vacuum leaks is to have the engine running and use a spray bottle of water on vacuum lines, intake gasket seams, EGR pod and the brake booster. A leak will reduce RPM or stall the engine.
For the internal tank filter, sometimes the plastic screen on the fuel pump deteriorates and clogs the pump intake. To test that, blow air into the fuel test port. This will help clear debris inside the tank temporarily, then check fuel pressure without driving the car and stirring the tank up. If pressure improves you know the root cause of your problems.

yes,

your statement is fuel pump work ok, have you tested for proper fuel pressure. just because the fuel pump works it could have less pressure needed to start the engine. maybe the fuel filter is plugged. start out by replacing the fuel filter, if this doesn't fix it, you need to pressure test the pump. even 10 psi reduction in pressure will allow the engine not to start.

Other than the idle control/throttle sensor the other items will not usually cause bucking or change of idle. After you drive awhile from a cold start the coolant temp sensor comes into play,then the EGR valve if vacuum is involved under load. So I quess your mechanic missed monitoring the 02 sensors after testing the fuel system. Hard to imagine. Have to road test hot for Egr and other drivability issues. You need a good drivability tech and always stick with best in their field. Hard to find. Have you ever gone for a drive with the person going to work on your car sitting in the pass seat. If they don't insist on that before they ever look at your veh or take your money--enough said. Did they call you to see if your happy with their performance? If not move on. MAF,AIT, most likely on idle and EGR on bucking. Quick look at 02 sensors You or they did a good job,Just didn't hit a home run,still on second base.

When was the last time the fuel filter was chg.? If thats not an issue best to get a fuel pressure test.

if you have not put a fuel filter on yet i would, and then do a fuel pressure test. if filter don't help and pressure is wright, might be water in fuel. do fuel filter, pressure test, fuel additive, might be cheap fix. if what i said don't work, and everything else checks out ok, then the only thing left is fuel regulator. but also don't loose sight of it being electrical too.