How do i check the fuel pressure on my 2.4 engine? It doesn't have a test port on the fuel rail.

To check the fuel pressure on a 2004 Chrysler Pacifica with a 3.5L engine, you will need to locate the fuel pressure test port. This is a small, threaded port that is usually located on the fuel rail. The fuel rail is a metal tube that runs along the top of the engine and supplies fuel to the fuel injectors.
To check the fuel pressure with a fuel pressure gauge, follow these steps:

1. Locate the fuel pressure test port on the fuel rail. It should be a small, circular port with threads on the inside.
2. Attach the fuel pressure gauge to the test port. The gauge will have a hose with a fitting on the end that screws into the test port.
3. Turn the ignition key to the "On" position but do not start the engine.
4. Observe the fuel pressure gauge. The needle should move to indicate the fuel pressure.
5. Compare the fuel pressure reading to the manufacturer's recommended fuel pressure specification for your engine. This information can usually be found in the owner's manual or by contacting the manufacturer.

Does it have spark ? Instead of trying to test fuel pressure , spray carb cleaner into the engine through the throttle plate or vacuum hose an see if it starts an runs ,at least till carb, cleaner is used up. What engine does it have ?

Engine Controls and Fuel - 2.8L
Engine Controls and Fuel - 3.6L
Engine Controls and Fuel - 6.0L

Fuel Rail
The fuel rail consists of 3 parts:
• The pipe that carries fuel to each injector
• The fuel pressure test port
• Six individual fuel injectors
The fuel rail is mounted on the intake manifold and distributes the fuel to each cylinder through the individual injectors.

You have to take the plastic cover off the top of the engine to see it .

Here are the usual suspects:
stuck fuel valve/float valve in the carburetor.
clogged fuel filter. or fuel line.
defective fuel pump.
electric fuel pump may be just a blown fuse, or wiring problem. good hunting.

There is a fuel pressure test port on the top of the engine in the pipe )also called the rail) that sits over and supplies fuel to the fuel injectors. You will need a special test gage to hook up to the test port valve. Below is a picture of a typical GM fuel supply rail and test port.

is this and EFI car, or CARB engine, 1990 (USA ) is a transition year.
my guess is USA< EFI.
with a fuel pressure gauge,
we do all 6 tests listed in the FSM. book.
but here are 2.
key on cranking presssure.
idling presssure.
if MPI enigne (engine not stated) we check while gunning the throttle.
test 3.
then leak down tests.
and injector balance tests.

with this.
http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

method varies by , 1.6L or 1.8L engines.

some cars have a fuel RAIL, MPI engines there is a test port there.
on some cars the fuel filter has fuel test port.

last but really first, is the engine, which is it>?>>???

• 1.6 L 4A-FE (L01) I4
• 1.6 L 4A-GE (LW0) DOHC I4

those are TOY name,, see that 4A >?
the L01 and LWO are GM names for the the engine
the FE means fuel injected engine.

• Geo Prizm base model (based on Toyota AE92 chassis) 1989-1997

sadly there is no, fuel rail fitting, (you'd have make one)
the FSM shows removing the fuel filter. output. line
and connection the guage there.
The fuel pressure should read 38-44 psi
key on pressure not running.
RAIL method beats all test. bar none !
and is.
running would be about 5PSI less. from what you got above.
if not a drop running, the FPreg (FPR) is bad. or
you lost vacuum to it. the vacuum of the running engine
drops pressure,.
that is just 2 tests. there are more , ask.
on my cars lackng rail fittings, i add a Schrader valve, (fuel rated)
from summit racing.

any thing you do here, must be rated for 75PSI,
no funky carb lines. hose and what not are going to work. here.

1.6L DOHC (same way as the ISUZU impulse ) same car.
4XE1 engine twin cam.
has MPI injection with fuel rail, regulator and loop
disconnecting the feed line and stuffing it with guage only does 1 of 5 tests. done on MPI. it does JUST the shut test.
the correct way it to check it at the filter or rail tests ports on most cars.
in some cases you must add it.
they sell banjo fittings with test ports at summit racing dot com.
so the first question on all MPI cars, is , where is the stock fittings.
other cars the rail has a schrader valve or a plugged hole to add one. (test port) did you look first for this?
to test the FPR, unplug the vacuum line running
and pressure will jump up 6 to 10 psi.
this simulates wide open throttle pressure, a key fact in getting full power from engine, i test cranking presssure, idle, 3000rpm
and wot pressures to be sure the PFR is working, not just the pump.



the spec at the rail is.

Late 1986 to 1993 I-TEC MPFI system (after VIN 0908197)
Regulator vacuum line connected-36 psi
Regulator vacuum line disconnected-42.5 to 45 psi

the shunt test can hit 60 pis easy. do so for only 5sec.
as this stresses the pump .

the only rail drawing , shows no fittings (cheap buggers)



not even a cheap plug...

below is the twin cam, 1.6L
buy a TEE feeting, and put it at upper, red arrow.
use clamps rated for fuel injection, not chezzy screw band clamps as seen on carb cars. use the correct parts.
or you will get leak and it will not be pretty,
the filter as at 14 ID. this is the pressure feed side of the loop.
30 to 60psi , so all parts must be rated over 60, psi, (100psi is a nice goal)



now the words directly from the IMPULSE FSM.

Testing

1. Relieve the fuel pressure.
2. Disconnect the fuel line near the engine and install fuel pressure gauge T-connector in the line.
3. Connect the fuel pressure gauge to the T-connector.
4. Start the engine and check the fuel pressure, it should be:
5. 4XC1-Turbo and DOHC I-Mark, G200Z Impulse: 35.6 psi with the vacuum hose of the pressure regulator disconnected and plugged. 28.4 psi with the vacuum hose connected and at idle.
6. 4ZC1-Turbo, 4ZD1 Impulse and 4ZE1 engine: 42.6 psi with the vacuum hose at the pressure regulator disconnected and plugged. 35.6 psi with the vacuum hose connected at idle. Disconnect the VSV before checking pressure.
7. V6 engine: 9.13 psi at the fuel pressure line after the fuel filter.
8. 4XE1 SOHC and DOHC engine: Flow test, disconnect the hose from the EFI fuel feed line at the engine and place in a suitable container. Apply battery voltage to the fuel pump. Pump should supply 1/4 quart (0.24L) within 15 seconds. Pressure test, connect a pressure gauge in the fuel pressure line after the fuel filter, located at the driver's side frame rail. Disconnect the vacuum hose from the pressure regulator. Apply battery voltage to the pump. After the pump stabilizes, the pressure should be 35-38 psi (245-256 kPa) and hold steady.

At the rear of the engine on top of the intake is a fuel delivery rail to the injectors, in the rail is a fuel pressure test port that looks like a tire fill valve. You need a special test gauge to tap in, you can buy one at most auto parts stores that works with most makes fuel pressure ports.

Hi.

If fuel pressure is low and you have already replaced the fuel pump, then the problem is usually the fuel pressure regulator. The pressure regulator is in same assembly with fuel filter. The assembly is located to the fuel tank, bolted to the truck's frame. The pressure is tested connecting a gauge like this : Set Sealey VSE952 to the port on the fuel rail. The pressure on Grand Cherokee must be around 49 psi plus or minus 5 psi. If engine runs but pressure is below 44.2 psi , check for a blockage in fuel supply line between fuel rail and fuel pump module (e.g.kinked line). If the line is not blocked, replace fuel pressure regulator and filter. Test pressure with and without fuel cap on.

Another test to be done is reading pressure, then shutting the engine off with the gauge connected. If pressure goes down too quick, then the regulator is defective. After 5 minutes the pressure should not go below 24 psi. If it does replace the regulator.

If regulator is OK check for leaks at the injectors that can cause fuel pressure drops.To check for injectors leakage clamp off the rubber hose of the pressure gauge tool between fuel rail and the port. If pressure staysr above 24 psi and before was dropping, then a fuel injector or the fuel rail is leaking.

Below a diagram representing the fuel rail and test port. The engines from same years like your six cylinder have the port and rail in the same position.






Regards.

Ginko

The fuel pressure should be 49 psi. On all engines except the 3.0 liter you can check the fuel pressure at the fuel pressure test port located on the fuel rail. On the 3.0 liter engine you can disconnect the quick-connect fuel line fitting at the fuel rail and install a fuel gauge with a (T) fitting and adapters to check fuel pressure. Start the engine and check the fuel pressure. Hope this will help.

Keep in mind that you have several components there:
- Fuel Pump Sender Assembly,
- Fuel Pressure Regulator,
- Fuel Rail Assembly, and
- Fuel Injectors.

1.- Fuel Pump (Sender Assembly) - TESTING
Refer to the accompanying charts for fuel pump diagnosis and testing.

The fuel injection system remains under pressure, even after the engine has been turned OFF. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and/or personal injury.



Fig. 3.1L engine OBD system check to be done before fuel pump relay circuit diagnosis




Fig. 3.1L engine fuel pump relay circuit diagnosis (1 of 2)




Fig. 3.1L engine fuel pump relay circuit diagnosis (2 of 2)




Fig. View of the fuel pressure test port (Schrader valve)-3.1L engine

A - 3.1L engine fuel system pressure test (1 of 4)
B - 3.1L engine fuel system pressure test (2 of 4)
C - 3.1L engine fuel system pressure test (3 of 4)
D - 3.1L engine fuel system pressure test (4 of 4)



Fig. The fuel pump/fuel sender module assembly is mounted in the fuel tank


2.- Fuel Pressure Regulator - REMOVAL & INSTALLATION

(the fuel pressure regulator, which is located on the fuel rail assembly)

NOTE: Before removing the fuel regulator assembly, place a clean shop towel under the regulator to catch any fuel drips

1. Properly relieve the fuel system pressure.
2. If not done already, disconnect the negative battery cable.
3. On the 3.1L engine, remove the intake manifold plenum, as outlined in .
4. On the 2.4L engine, remove the fuel rail. Refer to procedure earlier in this section.
5. Detach the vacuum line from the regulator.
6. Place a shop towel under the regulator to catch any fuel that may drip out. Unfasten the fuel pressure regulator retaining screw, then remove the regulator by twisting and pulling it from the fuel rail.
7. Remove and discard the O-ring seal. Inspect the filter screen for contamination and replace if necessary.
   

To install:

1. Prior to assembling the pressure regulator to the fuel rail, lubricate the new rail-to-regulator O-ring seal with clean engine oil.
2. Place the O-ring on the pressure regulator and install the pressure regulator to the fuel rail.
3. Install the retainer or coat the regulator mounting screws with an approved thread locking compound and secure the pressure regulator in place. Tighten the mounting screw to 76 inch lbs. (8.5 Nm).
4. If removed, install the fuel rail assembly to the engine.

WARNING The fuel return pipe must be connected before tightening the regulator retaining screw to prevent the regulator from rotating. Rotation of the regulator could damage the retainer and spacer bracket and lead to a fuel leak at the regulator inlet.

1. Connect the fuel feed line and return line to the fuel rail assembly, use a backup wrench on the fittings to prevent turning.
2. Attach the vacuum line to the regulator.
3. On the 3.1L engine, install the intake manifold plenum.
4. Connect the negative battery cable. Turn the ignition to the ON position for two seconds, then turn it to the OFF position for ten seconds. Turn again to the ON position and check for fuel leaks.

continue...