nexus6 wrote:
WWDiesel wrote:
If it was a fuel filter issue, it would affect it a whole lot more while running than at startup!
From what you describe, it sounds like it may not be building proper fuel rail pressure at times to allow the injectors to fire while cranking?
There are several things that can play into this!
Fuel Pressure Solenoid end of fuel rail
Fuel Rail Pressure Sensor side of fuel rail
The below two items are the same thing, but you may see them called two different things.
Located on back of CP3 injection pump:
Fuel Pressure Regulator
Fuel Quality Solenoid
You really need to know what your fuel rail pressure is doing when this phenomenon happens in order to do a proper diagnosis!
GordonCRD on this forum is really the subject matter expert in this area!
is there any way i can check the fuel pressure? or check the functionality of the solenoid or pressure sensor? ILl check my OBD reader but i dont think it has fuel pressure as a field i can view
update
ok I connected torque pro to my OBD reader and when it does this rough running the pressure fluctuates fairly wildly. But I feel this could be a symptom rather that a cause. what sort of values should I bee seeing?
Id love it to bee the fuel filter head because I can replace that fairly easily.
I double checked what codes I'm getting
P0102
p0403
p1140
which are all related to the EGR system?
B2TAE - cant find any info on this one
B2tae would be some sort of Body (BCM) code, but I can't find any information either. Low voltage, dead batteries, or a jumpstart can sometimes make the modules vomit up nonsense codes.
Regarding your fuel heater I very much doubt it has anything to do with the symptoms you describe, but as it is a safety issue, I suggest moving it to the top of your list.
P0102 is a Mass Air Flow sensor circuit fault. It incorporates the Intake Air Temperature function, which may circle you back to the "Never when hot - Never when cold, - only when somewhere in between" issue. Do you know when this code appeared? Is it persistent? (comes back immediately after being cleared) or could it be an old code? I've had to do little tricks with the MAP sensor and Fuel Pressure Sensor right next to it. I don't know why, but they seem to be prone to have intermittent continuity issues. I don't know if it was wires or connector pins, but when I put new connector ends on, it hasn't happened since. My guess is from engine vibration working on them constantly.
P0403 Your EGR solenoid isn't making the ECM happy. This is normal after doing Weeks EGR "fix" Tunes can solve this issue, or, you can take the solenoid off the EGR valve body, plug it back into it's connector, and zip-tie it out of the way. I wrapped mine in rags so it wouldn't rattle about or wear on things.
P1140 Vacuum reservoir solenoid (over by the power steering fluid reservoir) shows an electrical fault of some sort. Could be the solenoid it's self, or just the wiring or connectors. It may also be an old code.
Have you cleared all of the codes, then see which ones come back? How they come back? Under what conditions?
I see you've tried a lot of things, so I'm not assuming you overlooked anything. I just want to make sure so we don't overlook things.
You state that your fuel primer button is always fully firm. I didn't see any mention of a fuel lift pump, but that statement leads me to believe you have some sort of lift pump installed? Please correct me if that is wrong. If you do, that would rule out a whole subsection of possible problems.
Most scanners - even my crazy little $25 POS I got from an Amazon Day Sale last month, - shows some elements of Live Data. If you have someone monitor that while you start up a few times, and drive around, it's slow, but you can log some data points of Fuel Rail Pressure to see what it's doing.
Diesels running rough when starting cold is normal, but when it's partly warmed up, all it should do, if anything, is just take an extra revolution or 2 to fire up.
The injector leakage possibility mentioned by others is a very reasonable theory, the problem is, if you don't live conveniently near a competent diesel service business, you may lose some days loss of use while things go back and forth. But that's the only way you will find out which injector is causing the problem, - if any. Most good shops have reasonable testing rates. The big bucks come out when it comes to replacing with properly tuned injectors. Captain Dean found that the ones from Britain can come already tuned to the same injector code as original, (you don't have to re-program the ECM) and the prices are reasonable?