Dodge Repair Questions? Ask a Mechanic for Answers ASAP
Hello and welcome! What size engine do you have? Are there any codes in the computer?
What is the fuel pressure at when cranking?
Ok, well, we need to check fuel pressure to start with. Maybe we have low voltage to the pump, restricted fuel line or filter or some sort of restriction in the fuel rail. Just because the pump is new does not mean the fuel pressure is good. We need to start by checking fuel pressure.
Fuel pressure should be 44 to 54 psi.
Please call me so I can assist you over the phone.
YES and YES
However, if we talk over the phone now, I can explain how the system works so you will know what to check next depending on the fuel pressure readings.
I do work during the week so it might be better to talk on the phone now.
Sounds good. Have a good night.
Hello! It's Amedee from just answer. I am just checking in to see if you need any further assistance?
Hello! 40 psi while cranking?
The fuel pressure specs are between 44 and 54 psi. Although that it out of specs, the engine should still start and run on 40 psi. Ths injectors should still open up while cranking.
YES, we will need to check fuel pressure while cranking.
You would need to check injector pulse using a noid light to see if the injectors are pulsing while the engine is cranking over. You would use a tool called a noid light.
No, one bad injector will not prevent the rest of them from firing.
Air in the fuel line will not cause this issue.
YES, with the pump off the fuel pressure will be less.
Just please check fuel pressure while cranking and reply back to me tomorrow.
Please watch my video.
You can get a universal noid light..
Or you can use the same set I have.. It has all of the application in it. YES, one of them will fit your truck.
TO be honest, I have never used a voltmeter to check the ground signal trigger to the injectors from the PCM. I dont even think you will get a relaible reading. You need to use a noid light.
The test light will tell you if there is power to the injectors while cranking. It can also check the ground signal trigger going to the injectors but it is very tricky. You need to hook it up backwards and look very very close for a flashing light. It is very dim. This is best done at night or in a dark garage so you can see it flash. Again, it will be extremly dim and will flicker as the engine is being cranked over.
Ok, lets stay that there is injector pulse and everything is working good. So there is fuel pressure and injector pulse. This means the engine has fuel. That only leaves no spark and or no compression. We would need to check those next.
But if it runs on starting fluid, this means it has spark and compression. Maybe you have bad injetors or even bad gas??
If the engine runs on starting fluid and your sure it has injector pulse, then either the engine is flooded, not getting enough fuel because the injectors are not opening up enough or you could simply have bad gas. I supoose the injectors could be bad.. but what are the chances all injectors went bad at the same time? I have seen gas sitting around for a year still work just fine. This means something could have been mixed with the fuel.. such as water??
Well, if the vehicle sits and it was raining during this time, this could be it. Something could have allowed rain water to get in the tank..
Hello and sorry for the delay! YES, the noid light in that kit will fit your truck. If what you are telling me is true, then it has to be bad gas. However, you would not want to drop the tank without knowing for sure.. so be sure to check injector pulse first.
You could jumper the fuel pump relay to run the fuel pump constantly. Disconnect the fuel line at the fuel rail and drain the fuel into a bucket. Once all of the fuel is out of the tank, you could then add fresh gas and see if tht does the trick. You could then take a close look at the gas that came out of the tank. Just an idea..
Lol.. I think that was more than just one question. :)
You can remove the fuel pump relay and jumper the relay to allow contant power to the fuel pump.
No, it should not run contantly with the key on.
YES, you could unbolt the fuel rail and lift the injectors up (still attached to the fuel rail) and see if they spray while cranking the engine over.
Hello Bill! IF the IAC is bad, all you have to do is step on th gas pedal a bit while cranking and the engine will fire up. This will allow air into the engine (if the IAC motor is stuck closed) and it will start with no problem. YES, this is possible.. but I would have thought you would have tried to step on the gas pedal just a bit while cranking?
If the noid light is flashing while cranking, then yes, the injectors should be opening up while cranking.
IF the battery is strong enough to crank the engine over, it is strong enough to open the injectors.
IF there is plenty of fuel pressure while cranking, there is no need to check the fuel pump relay. But you can always use a different fuel pressure gauge just to be sure you are getting a correct reading.
Any shop in your area should be able to dispose of the old gas for you.
I know we have been working on this a while now and I have not yet been compensated for helping you. I would appreicate a positive rating for my time and knowledge I have shared with you thus far. We can still continue our conversation even after you rate my answer. No extra charge.
I will be looking forward to your reply.
If you can get your hands on a fuel pressure gauge that has a vlave that you can open and leave open to allow fuel to flow freely out through a tube so you can take a fuel sample or just simple drain the fuel tank, then yes, go that route. If not, just unscrew the fuel pressure line from the rail and run a hose to a container.
Good morning! Thank you for that long reply with a lot of detail. YES, I understand the problem is not fixed yet. However, just because you dont have the right tools to accomplish this diagnoses does not mean I have A) not spent a lot of time with you and B) that my answer is not correct. Does that make sense?
YES, I will continue to work with you for as long as you need. All I ask is that you provide a positive rating once we are done here and that you do all of the tests correctly that I need in order to diagnose this problem.
Hello! It's Amedee from just answer. I am just checking in to see how things are going and to see if you need any further assistance? I see you have read/veiwed my last post but you have not replied back. Is there anything else I can assist you with? Is there anything I can clear up for you? Please let me know so I can help. Thank you!