Cold Start Barely Start
#21
01-25-2012, 12:53 PM
Fuel pump should prime for about 3 seconds at initial key on. Should be on solid while the engine is turning. (no matter whether you are cranking, or it is actually running.) All controlled by the PCM. (it controls relay ground.)
Hook up the gauge, put it where you can see it from the drivers seat, and crank the engine, see what cranking fuel pressure looks like. The pump can make all the right noises, but still not put out adequate pressure to run the engine.
Hook up the gauge, put it where you can see it from the drivers seat, and crank the engine, see what cranking fuel pressure looks like. The pump can make all the right noises, but still not put out adequate pressure to run the engine.
#22
01-25-2012, 12:57 PM
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#23
01-25-2012, 01:05 PM
Your fuel pump is toast. Either that, or the regulator died. Not sure if there is a good way to test the regulator, aside from replacing it.... but, if you are going to go thru all that, just replace the whole thing, and be done with it. Go with a good name pump though, denso, or delphi. Stay away from airtex, or dorman.
#24
01-25-2012, 01:06 PM
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Originally Posted by Thomas Ellis
lets stop throwing money at it.do we have power & signal at the injectors.a bad crank sensor will not send a fire single to the injectors. to low fuel pressure and the injectors will not fire.i wood start here.
#25
01-25-2012, 02:04 PM
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I took a 5 gallon bucket, filled it full of fuel, put the pump in, plugged her into and she made a bunch of noise and pumped fuel. While I know that a pump can pump the correct PSI but incorrect Gallons Per House or vice versa, but I dont think the fuel pump is an issue. Here is another video.
#26
01-25-2012, 02:53 PM
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FOR SOMEONE WHO WORKED ON DODGES FOR 5 YEARS THEY SHOULD KNOW THAT THE CRANKSHAFT SENSOR SENDS PULSES TO THE ENGINE CONTROLLER TO CONTROLL TIMING AT DIFFERENT ENGINE SPEEDS. IT IS ALSO THE SIGNAL FOR THE CONTROLLER TO BEGIN ITS FIRING SEQUENCE.
ALSO IT IS THE PICKUP IN THE BOTTOM OF THE DISTRIBUTOR KNOWN AS THE CAMSHAFT POSITION SENSOR WHICH RUNS THE FUEL PUMP. IF YOU HAVE NO POWER @ THE COIL, YOU NEED TO DETERMINE WHERE IT IS LOST. THE COIL HAS TO HAVE POWER TO SPARK. ONE OF THE WIRES ON THE COIL IS SUPOSED TO BE HOT IN THE START AND RUN POSITION OF THE IGNITION SWITCH. THE OTHER WIRE ON THE COIL COMES FROM THE DISTRIBUTOR. THERE IS ONLY ONE OR TWO WIRES ON THE IGNITION SWITCH YOU NEED TO START A VEHICLE.ANY VEHICLE. (OLDER CARS ONLY NEEDED ONE) THESE ARE KNOWN AS IGNITION WIRES # 1 & 2. THESE WIRES ARE HOT IN THE RUN & START POSITION AS WELL. THEY POWER THE FUEL SYSTEM AND THE IGNITION SYSTEM. IF YOU HAVE EVER INSTALLED A REMOTE STARTER YOU WILL KNOW EXACTLY WHAT TWO WIRES I AM TALKING ABOUT. IF THE DIST. BOX HAS POWER THEN IT IS DEFINETLY NOT A PROBLEM WITH THE IGNITION SWITCH OR ANY OF THE WIRES NEAR THE STEERING COLUMN. ANYHOW YOU HAVE TO FIND OUT WHERE THE COIL GETS ITS POWER FROM AND SEE WHY IT ISN'T THERE. YOU CAN BYPASS THIS AND RUN A SWITCHED POWER FROM ANY WIRE THAT IS HOT IN THE RUN AND START POSITION ONLY. REMEMBER TO FUSE THE WIRE IF YOU DECIDE TO DO THIS. PLEASE LET ME KNOW IF YOU FIGURE IT OUT . ANY MORE ? JUST ASK.
ALSO IT IS THE PICKUP IN THE BOTTOM OF THE DISTRIBUTOR KNOWN AS THE CAMSHAFT POSITION SENSOR WHICH RUNS THE FUEL PUMP. IF YOU HAVE NO POWER @ THE COIL, YOU NEED TO DETERMINE WHERE IT IS LOST. THE COIL HAS TO HAVE POWER TO SPARK. ONE OF THE WIRES ON THE COIL IS SUPOSED TO BE HOT IN THE START AND RUN POSITION OF THE IGNITION SWITCH. THE OTHER WIRE ON THE COIL COMES FROM THE DISTRIBUTOR. THERE IS ONLY ONE OR TWO WIRES ON THE IGNITION SWITCH YOU NEED TO START A VEHICLE.ANY VEHICLE. (OLDER CARS ONLY NEEDED ONE) THESE ARE KNOWN AS IGNITION WIRES # 1 & 2. THESE WIRES ARE HOT IN THE RUN & START POSITION AS WELL. THEY POWER THE FUEL SYSTEM AND THE IGNITION SYSTEM. IF YOU HAVE EVER INSTALLED A REMOTE STARTER YOU WILL KNOW EXACTLY WHAT TWO WIRES I AM TALKING ABOUT. IF THE DIST. BOX HAS POWER THEN IT IS DEFINETLY NOT A PROBLEM WITH THE IGNITION SWITCH OR ANY OF THE WIRES NEAR THE STEERING COLUMN. ANYHOW YOU HAVE TO FIND OUT WHERE THE COIL GETS ITS POWER FROM AND SEE WHY IT ISN'T THERE. YOU CAN BYPASS THIS AND RUN A SWITCHED POWER FROM ANY WIRE THAT IS HOT IN THE RUN AND START POSITION ONLY. REMEMBER TO FUSE THE WIRE IF YOU DECIDE TO DO THIS. PLEASE LET ME KNOW IF YOU FIGURE IT OUT . ANY MORE ? JUST ASK.Well problem solved. Thanks for all of your help, P.B. you were right on the mark. I found the crankshaft sensor tested good when tested with a meter. However when I removed it to test it I found a large piece of a magnet stuck to it. Where the magnet came from I do not know. To test it remove the crankshaft sensor and leave it plugged in, turn the ignition on and pass a piece of metal like a putty knife across the end of the sensor, If the sensor is good you will hear the fuel pump cycle and a few relays click. Also if anyone else runs into a no start problem on a Ram a Dodge Tech told me that is real common for the ECM to lose its ground
#27
01-25-2012, 03:07 PM
The first part by PB isn't quite accurate for the trucks. No clue about wherever it came from. Cam position sensor has nothing to do with the ignition circuit. All it is for is to tell the pcm where in the firing sequence the engine is, so it knows which INJECTOR to fire. PCM gets ALL of its cues for the coil from the crank sensor.
In your test videos, you did not build pressure at fuel pump prime, nor did it build pressure while cranking. Try your bucket test again, but, put your thumb over the output. My guess is, you can easily stop the flow.
In your test videos, you did not build pressure at fuel pump prime, nor did it build pressure while cranking. Try your bucket test again, but, put your thumb over the output. My guess is, you can easily stop the flow.
#28
01-25-2012, 03:28 PM
Champion
It sounds to me like you may have a leaky fuel line causing the fuel to drain back over time or a plugged fuel filter (or weak pump). Could a really stretched timing chain cause harder starts? I know its a long shot to even consider but I'm curious.
have you pulled a plug and checked for gas after a failed cold start?
Last edited by Augiedoggy; 01-25-2012 at 03:33 PM.
#29
01-25-2012, 03:42 PM
The pressure tester needs to be hooked up to the rail. Turn the key to the on position(not starting) and see what the pressure does. It should hold at the required pressure for at least an hour, -5lbs in that time. If it does not, the regulator is toast, simple as that. If it does, start the motor and watch the gauge. And instead of removing the fuel pump 900 times, a flow test can be done right at the valve on the rail.
#30
01-25-2012, 04:05 PM
Champion
OP did say its even hard to start with ether.... would that still be the case with a weak pump?
never mind my question was answered later in the thread..
I have a vw kitcar that does the same thing but only after sitting for a few weeks because the fuel drains back in the lines and the fuel pump is too leak to reprime it without actually manually siphoning or blowing it through
never mind my question was answered later in the thread..
I have a vw kitcar that does the same thing but only after sitting for a few weeks because the fuel drains back in the lines and the fuel pump is too leak to reprime it without actually manually siphoning or blowing it through
Last edited by Augiedoggy; 01-25-2012 at 04:41 PM.