17,000psi... now that aint right?

I'm not exactly recommending this BUT if you pull the plug off the FCA it will default to max rp. If it maxes out the rp gauge then you know its not a weak cp3.
 
Huntingman27062 said:
pulled the banjo bolt and ran a reg bolt in it... well... a oil drain plug that actually fits fine and you can get them at any autoparts store... ive seen these $40 custom made bolts but thats dumb to buy... got mine from autozone...
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Fuel will leak past the bolt you put in. replace it with a real cap.
 
jsf350 said:
snap on scan tool will show- called for and actual recieving fuel psi
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see that just reminded me... when they checked my fuel pressure... AandM diesel in macon ga... the called for always matched what it said i was turning... and neither went higher then 17k... going down the road or anything... they always matched.... but never matched what the book said i should have which i think was 23k or something...
 
TheBigNasty said:
I'm not exactly recommending this BUT if you pull the plug off the FCA it will default to max rp. If it maxes out the rp gauge then you know its not a weak cp3.
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ive done this on accident... pops a code too... but i didnt try it when i was checking fuel pressure... hhmm...
 
TheBigNasty said:
I'm not exactly recommending this BUT if you pull the plug off the FCA it will default to max rp. If it maxes out the rp gauge then you know its not a weak cp3.
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do it at idle only

Huntingman27062 said:
see that just reminded me... when they checked my fuel pressure... AandM diesel in macon ga... the called for always matched what it said i was turning... and neither went higher then 17k... going down the road or anything... they always matched.... but never matched what the book said i should have which i think was 23k or something...
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23k is normal from cummins-- is funny yours is only saying 17K (PERIOD)

even tried testing in od @ wot?
 
JasonCzerak said:
Fuel will leak past the bolt you put in. replace it with a real cap.
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mmm unlikely but possible i guess... ill disconnect the line further down and see if any is still passing... when i took the banjo bolt off at idle in the first place it was barely leaking any fuel out... so its not real bad anyways... not this bad...
 
jsf350 said:
do it at idle only



23k is normal from cummins-- is funny yours is only saying 17K (PERIOD)

even tried testing in od @ wot?
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deff.. idle only... probly let jeff garmon do it since i dont have anything to read it...

yeah 17k at wot and od... and goingdown the road and everything... most it would get... and the "called for" stayed right there with it at 17k... roughly...
 
To find out if it's high fuel return, weather it be leaky tubes or bad injectors, separate the fuel return line that comes off the back of the head, put the end of the hose into a clear container, crank the engine over like you are going to start it, if more than a few drops of fuel come out while cranking it's in the injectors and/or tubes, if not it's most likely the CP3.


Not to be stupid but I don't see any lift pump mentioned in your sig...what kind of fuel pressure do you have at the CP3 inlet?
 
LReiff said:
To find out if it's high fuel return, weather it be leaky tubes or bad injectors, separate the fuel return line that comes off the back of the head, put the end of the hose into a clear container, crank the engine over like you are going to start it, if more than a few drops of fuel come out while cranking it's in the injectors and/or tubes, if not it's most likely the CP3.


Not to be stupid but I don't see any lift pump mentioned in your sig...what kind of fuel pressure do you have at the CP3 inlet?
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ok ill give that a try also...

ive got a gauge on it at the frame and run 9ish psi... in tank conversion... sorry... ill stick that in there...
 
i swapped in my original (tested good) injectors today... and made sure the dang injector tubes were pretty dang tight... 37lbs i know... but maybe alittle more this time around... the tubes looked good... no dents in the tips or cracks... new copper injector seals... still the same... in fact if anything it takes longer to start now then it did... probly 12 turn overs before it finally cranks... sucks real bad...

bout to list these extra injectors on ebay if any of yall are interested... like i said my truck ran the same with these in it as it does now so i guess there ok...

i coudnt see how to unhook the line off the back of the head to test for bypassed fuel or whatever... its tight back there and as it may be possible... but it doesnt look easy...
 
also went back and pulled the line off the top of the relief valve and started her up... she didnt leak a drop from the valve... only the line of course... but it used to... guess that has to do with the pressure being so low... i dunno... didnt leak at idle or reving it up... before it drizzled at idle... i was going to put the banjo bolt back in it but i lost the dang thing... could have sworn i put it in the glove box...
 
LReiff said:
separate the fuel return line that comes off the back of the head


Not to be stupid but I don't see any lift pump mentioned in your sig...what kind of fuel pressure do you have at the CP3 inlet?
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where do i seperate this at exactly? i want to try it tomorrow... i also have a cap that i made awhile back but never used for the rail to cap off individual injectors... this should isolate a bad tube also correct? when i block off one line and the truck starts will it start right up and just run off the 5 or will it have a hard start cause its starting on 5 injectors...
 
Well first of all I wouldn't try the cap idea you have for the individual injectors.

The place he is talking about separating the line is actually the banjo bolt that connects the line to the back of the head. Not fun to get to but not impossible.

I think you have a priming problem and a programming problem. The hard start seems to be independant of the low rp. I think this because you said on the scan tool of Garmons the actual was matching the demanded. That tells you right there that the ecm is getting what it wants. You just need to find out why it is only calling for 17k. For the priming problem check to make sure you have no leaks anywhere in the fuel system...including the cap to the filter because they are known for cracking and leaking.

Who knows I could be entirely wrong, but this is the conclusion I come to from the symptoms described.
 
TheBigNasty said:
Well first of all I wouldn't try the cap idea you have for the individual injectors.

The place he is talking about separating the line is actually the banjo bolt that connects the line to the back of the head. Not fun to get to but not impossible.

I think you have a priming problem and a programming problem. The hard start seems to be independant of the low rp. I think this because you said on the scan tool of Garmons the actual was matching the demanded. That tells you right there that the ecm is getting what it wants. You just need to find out why it is only calling for 17k. For the priming problem check to make sure you have no leaks anywhere in the fuel system...including the cap to the filter because they are known for cracking and leaking.

Who knows I could be entirely wrong, but this is the conclusion I come to from the symptoms described.
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thanks abunch for the info... im gonna try and give that a try tomorrow but not sure if i can get it to hold the container and be able to turn it over myself... the thing with capping off each injector is kinda what i found in the cummins manuel when i researched the return test or whatever... except it said to do this with some special cap from dodge... and to measure the fuel return at each injector to find the bad injector/tube... my case probly a tube if it were to fail the test... i was tryin to see if i could bypass the return part by it fixing the hard start at the bad tube... if its a tube... wait? if its connected on the back of the block how in the world would i be able to hold a bottle back there up against the head flush or i there a smaller line or something? where does the line run to from the back of the block? would it be easier to disconnect it there? i guess i can look myself tomorrow... duh... lol...

it was actually AandM diesels (macon ga) scan tool that read this for me (called and they told me they could find my bad injector with there scanner... charged me $85 and couldnt do it... never going back)... but i want Garmons to check my FP again before i buy anything else... just to make sure...

ive changed the fuel filter twice since ive had this issue and they always came with a new o ring for the bowl so shouldnt be a problem... i dont leave any fuel spots anywhere or anything like that...

i dont know why its calling for 17k psi... i dont have a progammer or anything like that... boost fooler at the most... would timing do anything to cause this? ive done the tone ring mod... which you cant really screw that up... other then that nothing should have changed... maybe the pressure sensor is bad and reading more pressure then whats there? so in turn tells the cp3 not to turn as much? possible? i dunno...

i know you guys have given me several ideas and im trying them one by one but im always looking for more! im starting to get real ill as ive been fightin this issue for months now... finally got the money saved to rebuild my injectors... had them tested first cause it still didnt feel right and sure enough... still not fixed... if i had the money id just drop it off at Jeffs and say fix it... but i dont see that happening anytime soon... as much as we both would like it... lol...
 
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ive also drained my filter bowl... left it open... and hit the starter and got fuel from the pump so thats deff working... and ill look around for any other issues as well... on my 98 the sending unit was cracked where the nipples came out for the fuel lines and wasnt holding pressure... that was fun trying to find...

i dont understand why taking my boost fooler in and out doesnt make a power difference either... unless it does the same thing as my little eBay boost elbow... i know when i installed the BF it made a big difference...
 
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The line from the back of the head runs into the firewall side of the filter housing, directly opposite of the side the cp3/rail return connection to the filter housing.

Something I forgot to ask, is the hard start consistent or is it mainly after the truck has sat for awhile? You said you had a fuel press gauge...is there a way you can watch it when you start it after it sits for awhile, see if it takes a second or two to build psi or if its instantaneous.
 
i think its consistant... i just went outside and started it 4 times... the first time was alittle longer then the other three but the other three where the same... it has been sitting for probly 5 hours and its now about 40 degrees... there so many turn overs now that i cant keep count... 15ish maybe... its weird because it started better with the other injectors in it... but with the other injectors most of the time i would get a studder start and have to start again... but these tested good so maybe its just the way there installed or something... because these injectors started better before i took them out then they do now that there back in... lol... maybe it has to do with the seating of the injector tubes in the injectors more then it has to do with the injectors...

my fuel pressure gauge comes on with the radio so before i turned the motor over i looked at it and it was reading 7psi and everytime i started it it was at 7 or 8 psi... which i think 8 is where its suppose to be... so i seem to be keeping pressure up to the pump...

i read a link where the guy said he replaced his cascade overflow valve and it fixed his hard start... is that even possible or did he mean the overflow valve?
 
Not sure on that one. I imagine he meant his PRV...on the rail...but you have yours capped so that wouldnt matter. When you changed the injectors how did you reinstall the injector/connector tubes?
 
TheBigNasty said:
Not sure on that one. I imagine he meant his PRV...on the rail...but you have yours capped so that wouldnt matter. When you changed the injectors how did you reinstall the injector/connector tubes?
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followed one of these write ups that a big company did for there injector nozzles... dropped in the injectors... then the tubes... hand tightend the tubes... then torqued the injectors and put all that back together then toqued the tubes... thats what it said to do anyway... sounds like the smart right order to me anyway... 8inch pounds on the injectors but i did alittle tighter then that... 27ftlbs on the rockers and it said 37 on the tubes but ive read else wear to torque to 43...

well mines capped with my own bolt which the guy above made me question it but i still think its fine... either way the valve wasnt leaking today anyway
 
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Ok just wondering, that should work fine. I like to tighten the tube first then the injector but either way should work fine.
 
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