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Discussion Starter #21
So I have replaced both tanks do to broken parts in both tanks... fuel line have been changed on the frame rail.... I checked all the clamps as well.... I’m getting very steady fuel coming in... I literally took a shower in diesel trying to mess with that.....

when truck starts pressure builds up to 30-35 psi..... when crazy idling starts fuel pressure goes down by itself to 10psi... after engine being shut down pressure stays at 10 psi and slowly goes back down to 0 psi.

i Picked up a new pump few minutes ago and will replace it in the morning....

So it’s common to have a bad pump out of the box ?
 

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I wouldn't say common but it has known to happen. You sure the fuel lines aren't pinched of the fuel bowl somewhere. I had that issue on several
 

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Discussion Starter #23
I double checked both all fuel bowl connections. Now my supply and return are braided 3/8 ID coming from fuel tank switch but no kinks anywhere...... can that be because I’m not running solid tube for fuel?
 

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Highly doubt it
 

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Discussion Starter #25
Bugman and Doc in your opinion should I replace the mechanical pump in the morning? Maybe it is bad out of the box
 

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If that is causing your low fuel pressure then yes
 

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Discussion Starter #27
Doc I don’t really know how to see if that’s what causing my low pressure...... I’m over here arguing with my teacher about my fuel tank not being sealed and that could cause my return fuel not being right..... my fuel tank IS NOT sealed.... but the whole thing is full of gas....... please explain
 

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Lets start here..

Where are you testing the fuel pressure at?
 

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Doc I don’t really know how to see if that’s what causing my low pressure...... I’m over here arguing with my teacher about my fuel tank not being sealed and that could cause my return fuel not being right..... my fuel tank IS NOT sealed.... but the whole thing is full of gas....... please explain
I hope the tank is full of diesel and not gas. The tank not being "sealed" , I have no idea what that means. It is not a pressurized tank!
 

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Doc has you pretty much covered but I also don't know what you are saying when you say that the tank is sealed.

Also check the filter housing and see if it is full of fuel or if it is down a little. If it is down a little I would say that you got a bad pump.
 

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Discussion Starter #31
When I say tank is not sealed, I mean there is a tube that go inside the tank and there is a second rubber tube that it not sealed with a clamp
 

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Discussion Starter #32
Replaced a bad or weak mechanical pump that was purchased from Advanced Auto Parts.
So before I was getting 35 psi and it wouldnot hold at all, starts to drop after engine come on....
New pump I’m getting 60 -65 psi with shim mod ( that will be taken out).

I am still getting the same results as far as idling......Sounds just a littlebetter than the video but still the same......

what do yall think about EBVS? Can I have a bad sensor? The tube is clean. Sensor looks like crap and plugged up
 

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Sounds like you need to go back to the injectors
 
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I can understand the reluctance to swap injectors - the thought of fluids in the cylinders made me cringe! There are some good videos on YouTube that explain how to do them - bleed off the oil and fuel pressure way before, use / borrow a bore-scope to check out the cylinder to be sure nothing has gotten in there, etc.

But you need to swap the # 7 injector with a known good one, and if you cannot "borrow" one, you need to swap with one of your own. Good luck, Trif.
 
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Hello. Swap the injectors. Dry out the injectors bores with paper towels, pull glow plugs on the injectors you remove before cranking the engine this will allow any fluid left on the piston to escape without hydro locking and bending push rods. It will cranka long time before restart expect lots of exhaust smoke once it heats up. You will need to drive it hard about 20 miles to clear all the air from rails then you can get a good retest of the injectors. Look into the valve cover gaskets connection to be sure you don't have a burnt out connection. Before doing all this work.
 

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It sounds like you have a dead injector solenoid at idle. Easiest thing to do is remove your valve covers and start disconnecting the injector plugs one at a time, go through ALL OF THEM and see which one(s) make no change in the sound of the engine
[/QUOTE This is what and why a buzz test is one of the first things that should be done. It will tell you if the IDM is a possible issue. If all the injectors pass the test then you know it is not the solenoids on top the injectors or hopefully not the IDM, injector driver module.. I have heard cold engines do this and have found it is often the injector itself due to a lack of proper clearance between the armature inside the injector and the injector housing and also the proper clearance from the armature to the solenoid itself. Clearance should be .014 + but not more than .016 under the plate to the cover that is held down by 4 bolts, and shoot for around .006 between the top of the plate and the solenoid. Also if the issue continues even as the engine is warmed up, it could be caused by a faulty discharge nozzel and pintel valve leaking which causes timing issues for that cyl. The swap test is an easy process. Pull an injector from any one of the cylinders which you have pull the valve cover from. The firing order for these engines is a one off from most other common V8's. On one side you have 1-4 and the other side is 5-8. I have found conflicts with scanners identifying misfiring holes on these engine due to the scanner trying to pick which one is causing a power balance issue and telling me false information in the past. Doesn't happen regularly. But, you need to have someone run a power balance test and find which cyl is not doing its job. Once you know which hole is not contributing equally, have that injector tested for flow and leakage, you can check the solenoid yourself with an ohmmeter, or swap it with any of the others from the same side. This is easier than swapping injectors since you will not be removing it and running into the possibility of loosing the seal from the injector crush seal at the nozzle. There's a lot of advice out there that can get you into trouble by not doing the right thing with these engines so be wary. Do the scan first ! Trying to do what is said above here by disconnecting each injector one at a time is a good way to get yourself shocked !!! These injectors use a voltage that can hit you good. Also by disconnecting them this way will set a code in the PCM. It will not stay there after you reconnect and restart the engine but there is a possibility of damaging the IDM by doing this! It is also messy with the cover off,. engine running and trying to work with the plugs between the rockers while the engine is running.
 

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Hello. Swap the injectors. Dry out the injectors bores with paper towels, pull glow plugs on the injectors you remove before cranking the engine this will allow any fluid left on the piston to escape without hydro locking and bending push rods. It will cranka long time before restart expect lots of exhaust smoke once it heats up. You will need to drive it hard about 20 miles to clear all the air from rails then you can get a good retest of the injectors. Look into the valve cover gaskets connection to be sure you don't have a burnt out connection. Before doing all this work.
before you go the trouble to swap the injectors, plug in a known idm. they do wierd things when they get water in them.
 
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