LB7: I need help

[LB7 Lover 1994]

Okay guys, I just got my truck back from the mechanic today.

We had 100hp injectors put in, the fuel lines that run from the filter head to the FICM were replaced, two fuel lines were replaced, all return and feed lines were also replaced.

The main reason for it going to the mechanic was to have the injectors replaced.

The second reason was because after leaving it on incline for an extended period of time it will start, and then after 10-15 seconds it will die.

I am stumped, and have no idea what could be the cause of this.
I havent called my mechanic back yet because I just back from college about an hour ago.

Does anyone have any idea what so ever this could be caused by? Could this be the CP3.

Any opinions are greatly appreciated.

 

[Evan@InglewoodTrans]

Did they rebuild the fuel filter housing?

 

[LB7 Lover 1994]

I did that about 2,000 miles ago and he even done it again just to be 100% sure that was not the cause.

 

[AKlowriderZ71]

It does sound like air getting in the fuel line somewhere.

Usually bad CP3 will not make enough rail pressure to start at all, or just be too weak to keep up with high fuel demand under heavy load. Never seen one start, run, then die.

 

[o4dirtymax]

Do you have a lift pump...? After it dies will it start right back Up?

 

[LB7 Lover 1994]

No I do not have a lift pump. No I have to get out and pump primer button multiple times before truck will start.

 

[LB7 Lover 1994]

Usually bad CP3 will not make enough rail pressure to start at all, or just be too weak to keep up with high fuel demand under heavy load. Never seen one start, run, then die.

Thats sorta what I was thinking but I didn't know. Also I am so stumped by this and a little agitated that after spending $4,400 this problem is still existent, that I am just thinking of every single possible cause.

 

[AKlowriderZ71]

Well, you could use this as a legitimate excuse/reason to get a lift pump on your truck. Once your fuel system is running under pressure instead of vacuum, your leak will show up. Then you can fix it.

 

[LB7 Lover 1994]

Well, you could use this as a legitimate excuse/reason to get a lift pump on your truck. Once your fuel system is running under pressure instead of vacuum, your leak will show up. Then you can fix it.

Haha never thought of it that way. Ill have to try and pitch that idea and see how it goes over :roflmao:

 

[02greysixer]

Does it do it at all fuel levels or worse at below 1/2 or 1/4 tank

sent from a galaxy far far away

 

[LB7 Lover 1994]

All fuel levels it can be full and do it or it can have an 1/8 of a tank and do it

 

[deerejohn]

it sure sounds like the filter head. if you have to prime it up every time.

 

[superswamper003]

My truck is doing the EXACT same thing!! I cant figure it out, im going to replace the filter today and hopefully that will fix the issue. If not, then I have no clue how air is in the system

 

[DIESELMAFIAPER.LB7]

Make sure the filter is on tight ive seen that do this

 

[cat_dr.]

Also so another thing to check is the wif sensor. Mine was leaking causing the same issue after I rebuilt my filter head.


Roll Tide!

 

[02greysixer]

Get a long piece of 1/2 fuel line and bypass everything but the filter and lines going from the filter to the cp3. Take your piece of hose and hook one end on the filter on the inlet side then put the other end in a full fuel container on the ground next to the truck. Get it all primed and running then let it sit. Make sure your hose stays submerged in fuel. I'd zip tie a big nut or something to it. Also make sure your makeshift tank is below the filter head like the trucks actual fuel tank. If it's above you'll just gravity feed fuel in and the test won't be accurate If you still lose prime it's your filter head or something between that and the cp3. If you don't lose prime then it's something between the ficm and tank.

Or if you have the funds go ahead and buy a lift pump. You'll need one eventually if you plan to get a hot tune, that'll make it real easy to find your issue.

sent from a galaxy far far away

 

[superswamper003]

So what happened with this?? Did you find the problem?

 

[LB7 Lover 1994]

My mechanic ordered and installed a billet plug where the WIF sensor is supposed to be. But the filter head has a crack so now I am on the hunt for a used filter head.

 

[superswamper003]

Oh ok, mine is still acting up.. Its getting really annoying now, the only problem I can think of is the whole filter housing assembly is skrewed up, or the seals are bad.

 

[02greysixer]

A brand new filter head can be had fairly reasonable. Comes with a new filter, wif sensor and fuel heater all assembled. Ready to bolt on, hook hoses up and prime. I think I paid right at $150 from the dealer

sent from a galaxy far far away