No rail pressure

[Evan@InglewoodTrans]

I changed the injectors on the truck and now the truck has no rail pressure and I have no idea why ive been messing with it all day with no luck. Ive logged fuel rail pressure a few times and it stays at 150 psi wether just sitting with key on or cranking. However once this morning it spiked at 750 it seems to have gotten worse the more stuff ive tried lol. Here is what ive tried.
1 Made sure all the high pressure lines I touched and didnt touch are tight.
2 Disconnected fpr (just in case)
3 Cracked all the lines thinking maybe some air in the system. (on edit when i do there is fuel but it is foamy and full of air)
4 Removed the valve covers and reasembled the fuel lines to check for leaks
5 Checked and double checked the triple checked all electrical connections.
6 Only Pulled glow plugs on passenger side so far but no fuel coming out .

Any ideas ?

 

[sweetdiesel]

OK i would start with logging while cranking
then unplugg the regulator and see if it changes, if it does go to 160mpa then you know that the fuel rail sensor is working and you have no issues on the low pressure side.

if it doesnt change i would check the fuel rail sensor is plugged in and perhaps your FPR crapped out,

what about the fuse for the the injectors? check that?


get as much info as you can and eliminate all you can and we can figure it out

 

[sweetdiesel]

Dont check high pressure lines with your hands. Common rail can fluid jet your fingers


Just sayin:hug:

 

[x MadMAX DIESEL]

Dont check high pressure lines with your hands. Common rail can fluid jet your fingers


Just sayin:hug:

Heard dat, unless you wanna go get your hand spit open by the doctor

 

[sweetdiesel]

I know you said you checked all connections but injectors are all plugged in?

this may sound crazy but i had a reg stuck one time and gave it a FONZY tap and bang the truck fired

 

[Evan@InglewoodTrans]

OK i would start with logging while cranking
then unplugg the regulator and see if it changes, if it does go to 160mpa then you know that the fuel rail sensor is working and you have no issues on the low pressure side.This morning when logging fuel pressure it would change while cranking now it just sits right at 150 and doesnt change whether the fpr is plugged in or not.Either way it never got higher than 750 and that only happend once.

if it doesnt change i would check the fuel rail sensor is plugged in and perhaps your FPR crapped out,Checked the fuel rail sensor this morning and about 40 more times lol its plugged in

what about the fuse for the the injectors? check that? Not yet


get as much info as you can and eliminate all you can and we can figure it out

Thanks for the help :hug: any suggestions are great.

 

[sweetdiesel]

if des FRP went to 160 + mpa when you unplugged the regulator then im going to geuss the regulator is fubared since it cant make that......ASSuming you dont have low pressure issues.

Check the pressure at the brass thing of a majingy by the alternator,If its a LB7 you can just pull the hose off behind the special fitting. you will know if you have pressure by putting your thumb over it

 

[sweetdiesel]

Also make sure you boost the battery as you need crankng amps to make it work.

 

[sweetdiesel]

Do you have a lift pump? If not your not going to have pressure.

 

[sweetdiesel]

Do you have a lift pump? If not your not going to have pressure.

And in that case you better pump the crap out of the primer

 

[Evan@InglewoodTrans]

ya i have a lift pump.

 

[sweetdiesel]

for shits and giggles unplug the fuel rail sensor and crank it iver and log it.


this is a single cp3?


does your value change when boosting the battery?

 

[Evan@InglewoodTrans]

for shits and giggles unplug the fuel rail sensor and crank it iver and log it.


this is a single cp3?ya single cp3


does your value change when boosting the battery?

Not sure because they have been everytime ive logged I didnt want them getting weak from all the cranking

 

[sweetdiesel]

Not sure because they have been everytime ive logged I didnt want them getting weak from all the cranking

just when you think you have cranked too much, crank some more

keep a good charge and always log

 

[Noreaster]

So how did you make out last night?

 

[Evan@InglewoodTrans]

I'm still trying things as we speak it's driving me nuts.

 

[Evan@InglewoodTrans]

I managed to screw somthing up during the process I would love to know what there isnt that much there that i messed with. I really need a another set of lines to do more testing so I can eliminate anything after the rail other than that im at a loss here.

 

[Evan@InglewoodTrans]

Well after welding another set of feed lines shut and installing them to check if the problem was injector related I cranked a little bit and sure enough it built rail pressure fine. It's sucks but I'm just glad Im looking in the right spot now after tearing my hair out trying to figure it out.Thanks for the idea Trent :thumb:

 

[TrentNell]

Well after welding another set of feed lines shut and installing them to check if the problem was injector related I cranked a little bit and sure enough it built rail pressure fine. It's sucks but I'm just glad Im looking in the right spot now after tearing my hair out trying to figure it out.Thanks for the idea Trent :thumb:

good to know , if you need me to get them tested to see which ones are bad let me know , and yes having HP caps to isolate parts of the system is invaluable to diagnosing RP problems , glad it help Evan .

 

[Evan@InglewoodTrans]

I worked down the line replacing the full feed lines until rail pressure wouldnt build anymore to try and narrow the culprit or should I say culprits down.im just happy to hear the truck start. Thanks for all the suggestions simon i really appreaciate it :hug: