Question about Cars & Trucks

1 Answer

2003 Nissian Altima 2.5

Fuel pressure is running at 50 psi, checked injectors electrical with noid light and have spark at all cylinders and replaced the plugs. I know that the pressure should be 35 psi. could the problem be the pressure regulator or the injectors? I find it hard to believe all injectors would quit at the same time. I did read that high fuel pressure could keep the injectors from working.

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that gotĀ 5 achievements.


    An expert whose answer gotĀ voted for 20 times.


    Uploaded 5 video answers.

  • Expert
  • 141 Answers

You may have max fuel pressure when the engine is not running because the pressure regulator( if its a vacuum regulator ) does not have vacuum until the engine is running (they increase fuel pressure as vacuum decreases) to answer the question the fuel pressure even at maximum will not keep the injectors from firing

Posted on Dec 11, 2012


6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 1 Answer

SOURCE: 1999 Yukon cold start problems.

1999 Yukon Start Issue - I have replaced the octopuse, battery, fuel filter, fuel pump, still having problems starting in cold weather, sometimes after a heavy rain.

Any suggestions?


Posted on Dec 08, 2008

  • 116 Answers

SOURCE: 1999 chevy blazer wont start


if your losing fuel pressure after the pump runs the drain back valve in the pump has failed.

and i doubt that you are seeing enough fuel pressure to run a vortec engine.

low fuel pressure equals a non running vortec

Posted on Apr 11, 2009

  • 1071 Answers


crank sensor is bad

Posted on Jul 21, 2009

  • 15 Answers

SOURCE: 89 GMC K2500 5.7L TBI not spraying fuel

have you checked the coolant temp sensor? it controls air-fuel mixture.

Posted on Feb 04, 2010

  • 409 Answers

SOURCE: 1988 silverado, tbi 350 has 12 psi fuel pressure,

Fuel pressure is a little low, check the pressure regulator, and the fuel filter

Posted on Mar 09, 2010

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Paul Thanks for the info. Also I have replaced just about every part on this car and can not figure out why it runs for about 30 minutes then shuts off. What else can be wrong.

There are several thing that cause the engine to die. #1 Electrical Install a spark noid on plug wire this lights up as the plug gets it power if this signal is lost then test the crank shaft sensor L-6 engine located on drivers side of engine at transmission just to the left of master cylinder V-8 engines it is just behind the passenger cylinder head . #2 Fuel pump control test for fuel pressure at service port about 36 psi running and as you rev the engine it should go up 40-45 psi and when shut off it should retain pressure above 30 psi when dies check pressure loss of pressure could be due to fuel pump relay is bad #3 just the fuel pump is shutting off.

Apr 27, 2014 | 1991 Jeep Cherokee Limited

1 Answer

Misfire p0303

Check wiring harness around and including plug to the coil pack. Also check fuel pressure with vehicle running. I'm not sure of the specs but, Iit should be around 35 to 40 psi. at idle, and 50 to 75 at higher RPM's. I've seen Fords run with a bad fuel pump and demonstrate these exact symptoms

Mar 06, 2014 | Ford Cars & Trucks

1 Answer

High co reading for emission

what rpm or speed, both? which Civic engine????? of the 5
and what country????? we can not guess this... ever.
and no one ever says.. here. 99% true.
why is not easy. 50ways there are.
it's running rich. (we have one good input. this)

but here are the reasons, (not the 50 causes) all the below are tests.
it's misfiring. is rich misfire.
causes: many I'll assume the cars 12v power is 10 to 145v at all times. 13.3v running minimum.
1: low compression on one or more cylinders. 150psi w.o.t is min.
2: bad spark or not timed right. to any cylinders. or all. tests.
3: bad fueling. above must be good (tools used and tests)

now if compression is good. and the EGR main down leak
if spark is good, what causes high HC,
simple misfire.
what causes misfire.
  1. bad spark plugs (ever tune it up? now be the time, huh?)
  2. bad injectors, leaking or clogged. clean em.
  3. fuel pressure too high, 28 is min, max (see end)
  4. you find one injector , NOID lamp test stuck ON.
  5. o2 sensors stuck lean (exhaust leaks)
  6. Fuel pump regulator stuck closed, causing #3
there are 5 engines, (why not state yours.??????0
1.5 L to 3.0L
the fuel pressure is different on all .
40-47 PSI. 1.7L and 2.3L
47-54 PSI on 2.0L and 2.2L
41-48 PSI on 3.0L
and then the exceptions
1-- Except SULEV: 48-55 psi SULEV: 47-54 2 Except SULEV: 47-55 psi SULEV: 48-55 psi
if you read the FSM,, it shows tests at the rail.
fuel pressure.
fuel regulation test.
shut test
injector leak down test.
and the injector balance test.
we do them all, or fail;.
all this is FSM.

do you want us to guess or test?
the latter avoids the 50 guesses. 49 being wrong.$$$$$$$$$$$$$

Feb 24, 2014 | 2001 Honda Civic

2 Answers

I have a 89 rs camaro with the 5.0l can anybody offer suggestions on what the possible fuel system issues are with year and model? I've changed the fuel and air filters rebuilt tbi ran fuel system cl

check fuel pressure TBI injection fuel pressure should be 9 - 13 psi.make sure fuel pressure above 10 psi because throttle body need at least 10 psi. in order to work right.if all is good check see if PCM firing the fuel injectors.go to auto parts store buy noid use noid light you have to disconnect fuel injector electrical connector then plug noid light into fuel injector connector.crank engine watch noid light should blink meaning PCM is firing fuel injectors if noid light steady not blinking PCM not working.if noid light dont light up you have open circuit in the fuel injectors wiring.if check engine light flashing have vechicle code scan.bad tps sensor will also cause problem you are having.

Apr 03, 2013 | Cars & Trucks

2 Answers

P0 308

when the engine is cool spray carb cleaner around the intake manifold

Oct 10, 2012 | 2000 Ford F250 Super Duty Crew Cabs

1 Answer

Dead cylinder number 2 bad injector number 2

use a digital volt meter,put it on the ohm scale check number 2 fuel injector should be 11 to 16 ohms if not reads zero fuel injector faulty.if numbe 2 fuel injector okay.use noid light hook it to fuel injector electrical connector with fuel injector disconnected and see if pcm is firing the fuel injector noid light should blink when cranking the engine.if light steady pcm not firing 2 fuel injector,if noid light dont light up.there is a open in the wiring connector 2 fuel injector 2. if fuel injector okay,check spark plug, carbon foul you have a bad ignition coil or wire if you see oil on spark plug you have worn piston ring or leaking valve guides allowing oil to foul out spark a compression test check compression to see condition of the cylinder.

Sep 01, 2012 | 2005 Pontiac G6

1 Answer

96 nissan altima automatic. Wont start I turn the key and get nithung. Have piwer to the radio windoes etc but simpke.wont even begi. To turn

Hi there:Sound like a starter problem, also check battery charge. Spark, fuel and compression... all three of these are tested when the engine is being cranked over. There are two way of checking for fuel. Fuel pressure and fuel trigger. Both are very important and must be present for the engine to start. Fuel pressure is self explanatory. You just hook up the gage and see what the reading is. Fuel trigger is check with a noid light. The injector gets unplugged and the noid light gets plugged in to the injector clip. With the engine cranking over, this light must blink. This is the signal to the injectors from the computer. You can have all the fuel pressure in the world, but it wont matter if the injector is not pulsing gas into the cylinder like it should.

Compression tester, spark tester, fuel pressure gage and noid light are all accessible at your local auto store. All three tests play a very important part in diagnosing a no start condition. Be extremely careful when doing these tests.

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Aug 07, 2012 | Cars & Trucks

1 Answer

Engine turns over, but won't start!

what you need are two things....a set of injection noid lights and a fuel pressure guage. check the pressure at the rail (there might be a schrader port for this). If there is no pressure here inspect the fuel pump relay in the relay box. If you have around 40-45 psi at the rail once you cycle the key unplug the injectors one at a time and check for injector pulse.

Sep 20, 2009 | 2003 Nissan Altima

1 Answer

94 Altima Running Rough

MAKE SURE WIRES ARE GOOD, to check injector Get a noid light and take that injector plug and plug into noid light it should light up everytime injector would pulse.(IT SHOULD BE A STEADY PULSE) contact if you need more help

Dec 27, 2008 | 1994 Nissan Altima

1 Answer

Wont start

spark and fuel pressure at the times while it not starting? I hope so.
Will it start if you spray carb cleaner in the intake? If so we are dealing with an Injector issue Several injectors could be failing when hot It's very common also you need to hae a NOID light to verify that the injectors are being PULSED by the ECM if you have NOID and spark and fuel pressure then the only thing to do is while its stone cold. OHM all the fuel injectors and record all the reading for each cylinder.
Drive it then once it will not start, quickly do the ohms test again and record all readings again and any readings that are lower are likely bad injector windings and you need new injectors.
Any questions email me at please rate this advice

Oct 03, 2008 | 1992 Buick LeSabre

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

59 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cars & Trucks Experts


Level 3 Expert

76846 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

Randy Ohler

Level 3 Expert

14585 Answers

Are you a Car and Truck Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides