Engine/Transmission (1998.5 - 2002) Hard starting update

[Hookemupman]

I am still having the hard start symtoms cold or hot it just will not want to start,turns over fine just acts as if its not getting fuel. I have heard that the vp pump does not like excessive fuel pressure. I have about 15 pounds of fuel pressure. If i unplug the transfer pump and try to start it will fire right up so my question is my transfer pump putting out to much pressure. The truck runs perfect when it finally starts. Also if i crack the injector lines and tighten them up before trying to start it really seems to help,it will start almost instantly. I hope this makes sence what is happening. Thanks for any input. Jason

 

[DieselLady]

I am still having the hard start symtoms cold or hot it just will not want to start,turns over fine just acts as if its not getting fuel. I have heard that the vp pump does not like excessive fuel pressure. I have about 15 pounds of fuel pressure. If i unplug the transfer pump and try to start it will fire right up so my question is my transfer pump putting out to much pressure. The truck runs perfect when it finally starts. Also if i crack the injector lines and tighten them up before trying to start it really seems to help,it will start almost instantly. I hope this makes sence what is happening. Thanks for any input. Jason

I am having pretty much the same problem. I called 1-800-DIESELS and spoke with the Cummins Tech and he said it was the excessive pressure. In the manual it says you should have between 5-7 psi at cranking and a minimum of 10 psi at idle. It states that you will get a hard start if you have too much pressure at cranking. The tech said that the vp 44 needs a difference in pressure from the input to the timing side or the timing gets confused. Not sure why. So I installed a toggle switch to the wire that activates the relay for the fass so I could turn it off when I cool it down. If I leave the fass off for starting it turns over and starts right up. If I leave the fass on it does its 2 sec prime and I will get a hard start. Now the check engine light has come on and I get a P0122 code which is for the TPS voltage too low. I think this is from excessive cranking. If I use the toggle after three good starts the light goes back off. The only thing that does not make sense is I will still get a bad cold start in the morning even when I turn the fass off. But I may have more than one issue going on here. Haven't quite figured out if I am getting a little air in one of the lines after I installed the new injectors. One biggy to remember if you toggle the fass is make sure you don't forget to turn the fuel back on. I have done this a couple of times now and I am possibly going to get a delay relay instead of the toggle so I don't forget, or bye bye vp 44. I am going to go through all the injector tubes and recheck for leaks etc to make sure this is not the problem first. I don't like the idea of having to turn the fuel off each time I park the truck. I will also update if I find the solution to the problem. Betty

 

[nps]

I am still having the hard start symtoms cold or hot it just will not want to start,turns over fine just acts as if its not getting fuel. I have heard that the vp pump does not like excessive fuel pressure. I have about 15 pounds of fuel pressure. If i unplug the transfer pump and try to start it will fire right up so my question is my transfer pump putting out to much pressure. The truck runs perfect when it finally starts. Also if i crack the injector lines and tighten them up before trying to start it really seems to help,it will start almost instantly. I hope this makes sence what is happening. Thanks for any input. Jason

You might try to put a regulator on the fuel supply line. Believe aeroquip sells them. Read about it here.