New to this forum and short on time which is why I did not to a big search for what my issues are. If anyone can help it would be great, thanks.

I have an 03 CTD that I just installed a Raptor RP100 on. Now backing up a little. She would not start or would take a long time to start (hot or cold). Did what trouble shooting I could without a flow meter etc. Blew out all the lines, changed the fuel filters (trying out every brand of filter I could find), and have the OEM filter right now in her.

If I pull the filter out completely she will start with no issues what so ever, not even a full revolution and it will fire every time. Thought it was a flow issue. About a year back my son had a guy in Texas remove the OEM lift pump and installed the pump that goes in the tank, this is when all the issues started.

SO!!! If I have to remove the filter in order for her to start I figured it was a flow issue most likely caused by the pump in the tank. Bought the Raptor RP100 and install her last night. She started fine after I primered her and then let her sit over night. This morning got in her, and it took about 30 sec to start, tried it again this afternoon and now she will not start at all. If I pull the filter out I would bet a paycheck she will fire immediately, just as usual.

This is where I need some help, any suggestions as to what I need to look for? Thanks

 

Is your lift pump running? If you take the filter out and bump the starter it should pour fuel out of the top of the filter bowl.

 

Ok so it starts without the filter! Not really a restriction there when new. So move on to the CP3 It will self prime and actually pull fuel if the lift pump is not working! Do you have a rail guage? Maybe a inline fuel guage pre CP3? Several things in the fuel system will do this but without any guage readings your shooting in the dark! So get some guages!!

 

the lift pump was removed last year when it went bad. The guy who did the work put the mod with the pump in the tank. Ever since then it has been acting up.

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I do not have guages, which I know this is an issue and I am pretty much shooting in the dark. The one thing that strikes me as odd is that it will start just fine with no filter. After you re-install the filter, with in a day or so it will go back to not staring at all.

 

Sounds to me like you have a fuel leak down problem. If fuel stays primed it will fire every time. Here is a link to how to check fuel pressure How to check fuel pressure for Under $20 that is the cheapest place to start. The other choices are u have a leaking injector or a bad check valve in CP3 pump or in the fuel return

 

Had the same problem in my 03 ram. Placed draw tube in tank and installed airdog165 pumps mega fuel. Still had real hard starts.It turned out to be fuel pressure limiting valve which is on the fuel rail . cummins part is pricey.I bought a part from dr.performance for about 60.00 worked great

 

Is the in tank pump still in the tank, and fuel being drawn through it? The raptor may have a hard time pulling fuel through the tank pump.

 

thanks for all the information. I left out one piece however.

Yesterday when I tried to start her I first primmed her at the CP3 pump inlet line. Do any of you have a Raptor 100? If so, how much pressure should I have at the CP3 pump, when I crack the line? The reason I ask is that when I popped that line, not a whole lot of fuel comes out pretty much I get the initial squirt then it just runs down the side of the pump.

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Yes the pump is still there, and no it is not being drawn through the old pump. I cut the feed line from the pump and attached another piece of tube to it for the suction tube.

I am going to remove the tank either today or tomorrow. Look at the video I provided, I will do just that and make a suction tube identical to his.

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Thanks, I will keep that one in mind as well.

 

Where is said video?

 

Yea, not sure why the link will not show, but if you do a youtube search for "AirDog Installation - Video 2 of 2 " this will show you what I plan on doing. I have something similer done right now.


BUT!!!! Morning two, she started up this morning, a little long in the start but it started. Let her warm up then took her for s ride. Came back and turned her off, waited 30 seconds and tried to start her up again WITH NO LUCK. This is the second day in a row now that she will start cold and once warm she will not start again.

I have re-named this truck *****