Very good information.i have been doing my homework for a month on my lb7. Thank your for explaining the order of operations. Best on you tube and forrums 👍
@hddm3
5 жыл бұрын
Awesome. Very through! Thanks so much. Cant wait for more
@MrBusy427
7 ай бұрын
Excellent video
@sneakypete123
9 жыл бұрын
excellent video. would love to see a cummins return flow rate test and lift pump test. where to hook up and everything. keep up the good work. also do you find on cummins, the injector on time should also be 0.40ms if current ramping the injectors?
@PGFuelInjection
9 жыл бұрын
Yes, on the 5.9L engines the pulse width of the main injection event is about the same. This reading is taken at operating temperature.
@sneakypete123
9 жыл бұрын
PGFuelInjection thank you for the reply. keep the videos coming.
@ricardoayala5028
4 жыл бұрын
Thank you very much for all this info. My truck is a lb7 I don't have problem to start but at idle is rough no white smoke no power any help will be highly apriciated thank you
@PGFuelInjection
4 жыл бұрын
Checking the cylinder balance rates with a scan tool should point to which cylinder is the issue. A low number means an over fueling injector and a high number could either be an under fueling injector or in rare cases, low compression. If you have a surge at idle with fuel rail pressure, you may have an issue with the pressure regulator.
@ricardoayala5028
4 жыл бұрын
@@PGFuelInjectionthank you very much. fpr just got replace with an oem bosch search got better but still there I'll run an injector cleaner maybe that helps balance rate are very high
@JoelAutomotiveInaction
9 жыл бұрын
How did you performed that test to collect the fuel?? engine cranking 30 seconds or idling? thanks good video
@PGFuelInjection
9 жыл бұрын
Joel Automotive In action This test was done with 15 seconds of cranking. On LBZ and later engines there is an enhanced test done at idle with the rail pressure commanded to 120 MPa.
@mattm5423
7 жыл бұрын
Thanks for this video.
@robertriddle4822
Жыл бұрын
Thank you.
@gregd8038
2 жыл бұрын
And they say a Ford 6.0 is hard to diagnose or work on. Not as hard or complex as this. Just my 2 cents
@josep.7387
2 жыл бұрын
I had the same problem i just check the baterries and one of them was low voltage so i replaced it and problem fixed
@russellpugh5554
4 жыл бұрын
Would the same things apply for a lb7 with a hard start/long crank, but ONLY when warm. Has no white smoke and idles smooth
@PGFuelInjection
4 жыл бұрын
Yes, high return flow can show up as hard starting cold, hot, all the time, low power or any combination of the above.
@nicksinko4600
4 жыл бұрын
Russell did you find out what's wrong with your lb7... I have same issue
@russellpugh5554
4 жыл бұрын
Nick Sinko I had a leak in the fuel filter housing and it had would let the fuel leak down and lose pressure
@hamstercottage3942
Жыл бұрын
😢
@MrBusy427
7 ай бұрын
How do you get the truck to crank for 15secs without firing while doing the return test
@deanmckenze
8 жыл бұрын
did this truck have any other symptoms other than the long crank time.........Rough idle or smoke at idle or anytime?
@PGFuelInjection
8 жыл бұрын
This truck just had a hard starting issue. You can see in the video that the injector balance rates are within GM's spec of +/-4 mm3. Also the pulse width was around the 0.40 ms which is normal.
@chuckmaypole7378
4 жыл бұрын
No
@michaeldobovsky1528
5 жыл бұрын
i have a 2003 duramax . you will get an engine light on for bad glow plugs a code reader wont tell you which plugs are bad you have to test each one to find the bad ones.
@PGFuelInjection
5 жыл бұрын
Possibly on a California emissions vehicle but the only code that will set on a LB7 Duramax otherwise is for voltage feedback. This is just telling you if the relay supplied voltage to the glow plugs but does not indicate an issue with the glow plugs themselves.
@ap5598
5 жыл бұрын
make sure ignition is off, using a12v test light connected to battery positive touch each of the glow plugs on the end where the nut is holding the wire to the glow plug. If the light doesn’t turn on the glow plug is bad.
@mattm5423
7 жыл бұрын
Why don't mechanics that worked on my truck us logic like you do, instead of just saying LB7? Replace all the injectors and we'll see...
@cumminsmilitia2063
4 жыл бұрын
Did the injectors fix it?
@juanmoreno2675
2 жыл бұрын
Hi there, how do you make sure if is not your cp3 pump ?
@PGFuelInjection
2 жыл бұрын
Check out this newer video. kzitem.info/news/bejne/lqeq3KGfqGJ1e6w
@anthonyfilippini1102
4 жыл бұрын
What should the cranking RPM be on an LB7?
@PGFuelInjection
4 жыл бұрын
Cranking RPM should be a minimum of 150 but ideally around 180-200
@anthonyfilippini1102
4 жыл бұрын
Thanks for the reply. I’m having hard cold start issues with my LB7. I took it to a shop for a bad ficm and they said the return rates where all within spec. and the balance rates are good. They also installed a lift pump and cp3 pump because it was not making the desired pressure. My cranking rpm fluctuates between 140-180rpm and my fuel rail pressure is only getting to 1.1kpsi (7.58mpa). Do you think my cranking rpm could be causing the problem?
@PGFuelInjection
4 жыл бұрын
@@anthonyfilippini1102 Without seeing and hearing your engine cranking, it is hard to tell what is going on. Does it sound like it is cranking slow or does it have a skip? Actual FICM issues are rare on LB7 engines, what was the issue? A good fuel system should be able to build over 100 MPa at cranking RPM. Many shops install lift pumps for low rail pressure issues and then the CP3 but 80% of low rail pressure issues are injector related. What was the result of the injector return flow test? Also the fuel system needs to be checked for air.
@anthonyfilippini1102
4 жыл бұрын
PGFuelInjection I was having long cranking issues when it was cold, so I ran the AC Delco injector cleaner and top end cleaner though the engine (disconnected the fuel lines on the rear of the driver side and ran the cleaner mixed in a 1/2 gallon of diesel). That idled for almost 2hr. Then I connect the fuel lines back up and bleed the system. Drove it about 1/2 mile and it went into limp mode. Code was for the 1 bank of injectors not firing. I took it to a shop that specializes in diesel repairs near me. They said it had a major air leak in the fuel, and said they recommend installing a lift pump with bottom sump in the tank, they didn’t think that was my only issue but could do other tests before the air leak is fixed. They installed the lift pump, still didn’t run. They had a used FICM they put on and said the truck starts right up and drives ok, but my rail pressure was a little low when driving. They said there was no air leak (the primer button is rock hard, I can’t push it down at all). I asked them about the injectors and they said the balance rates are good and the return rates are good (I’m not sure how they did the fuel return test and the actual results). They recommend welding up the fuel pressure relief. They did that, and said the fuel pressure is still low when you get on it, and said the cp3 pump is bad. They assured me my injectors are good, so I had them install a CP3. I got the truck back and the truck runs great (more power then it ever had), but the next morning it took about 10sec to start at 40degees F. Lately it has been getting worse and sometimes it won’t start unless I plug it in. When cranking gray smoke is coming out the tail pipe, so I think it’s getting fuel? But once it starts a puff of black smoke comes out and the gray smokes clears up in a couple of seconds. Yesterday I saw my cranking rpm only went up to about 130 rpm. I cleaned my engine grounds and now on my edge monitor the cranking rpm go from 140-180rpm, but it sounds smooth. I started this morning in about 8sec with a coolant temp of 36deg F. So it’s starting quicker. This morning I did a voltage drop test on the starter and glow plugs. The stated was good, but the positive on the glow plugs was 2.2V. I have to look into that. I also bought a new starter I’ll install. I’ve been cranking my a lot and I think it’s original, I’ll see if that will get my cranking rpms up a little more. I really hope is not injectors!
@PGFuelInjection
4 жыл бұрын
@@anthonyfilippini1102 Was the repair facility a diesel performance shop? In our shop the diagnosis would start from the beginning. Is the rail pressure slow to build when the starting issue is present? From there a pressure/vacuum gauge is installed as well as clear fuel lines to look for air. If that checks out, the fuel system is commanded to full pressure at idle 160 MPa. If the system cannot build this pressure, there is an issue. The CP3 pump can be tested with a scope to verify all three plungers are functioning. Next is the injector return flow test. During this test the pressure relief valve is tested to see if it is leaking as well This can be done in about one hour and pin point the source of your issue 100% We also would test the glow plug and intake air heater system. More than half of the trucks we seen have burn out glow plugs but since they set no codes on the LB7 the customer is unaware. This engine will start without glow plugs down to about 15°F.
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