04 lb7

[turbojoe]

Got a friends all stock 04 LB7 277k and she just quit running. started running a little rough (NO SMOKE) then quit. changed fuel filter/primed/new rebuilt filter head.. still nothing. No codes or nothing.

Ive been looking at all of the hard/no start theads and everything that people have found out is still good on this truck.

-Absolutly no smoke out the tail pipe while cranking
-the EDU fuse is not blown or any other fuse.
-swapped EDU relay also
-bale connector wires and wires by FICM are not chaffed
-even checked under the fuse panel for wire chaffing/connections
-Tryed different FICM still nothing
-Has Cam and Crank signal present while cranking
-has 4500-5800 rail psi while cranking
-cranks at 185-205 rpm
-efi live says 1.9-2.1 mil.sec. for all the injectors
-Has an Edge/attitude BUT i unplugged it so thats out:thumb:
-it gets plenty of fuel to the filter/plunger is hard
-it has never had an extended cranking problem...so i dont think return rates are a problem.
-and it cranks unusually fast, that the exhaust hits something under the truck
- im sure i didnt mention some other things that i tried but these came to mind at the moment.

So as you can see im just about out of ideas

Any help would be awesome.
Thanks,
Joe

 

[blk smoke lb7]

pull each fuse to check it,i had a fuse check good and i finaly replaced the injectors as a last resort and when it didnt fire after that we pulled each fuse instead of just checking with a probe to the tops and we found the fi fuse blownlow on 1 side and it curled up and touched the other side so it showed good on both tops of the fuse

also there is a very big 125 amp or 175 amp under the plastic shroud of the fuse box i blew that 1 also just something else to check any diesel in the oil?

 

[calabria69]

Regulator???

 

[blk smoke lb7]

fprv maybe letting the presure go to the tank instead of the injectors

 

[turbojoe]

no diesel in the oil either. i unplugged the regulator and still nothing.

which fuse did you say was blown?

thanks,
Joe

 

[turbojoe]

Checked all the related fuses including the mega fuse....still nothing

 

[Chevy1925]

Got a friends all stock 04 LB7 277k and she just quit running. started running a little rough (NO SMOKE) then quit. changed fuel filter/primed/new rebuilt filter head.. still nothing. No codes or nothing.

Ive been looking at all of the hard/no start theads and everything that people have found out is still good on this truck.

-Absolutly no smoke out the tail pipe while cranking
-the EDU fuse is not blown or any other fuse.
-swapped EDU relay also
-bale connector wires and wires by FICM are not chaffed
-even checked under the fuse panel for wire chaffing/connections
-Tryed different FICM still nothing
-Has Cam and Crank signal present while cranking
-has 4500-5800 rail psi while cranking
-cranks at 185-205 rpm
-efi live says 1.9-2.1 mil.sec. for all the injectors
-Has an Edge/attitude BUT i unplugged it so thats out:thumb:
-it gets plenty of fuel to the filter/plunger is hard
-it has never had an extended cranking problem...so i dont think return rates are a problem.
-and it cranks unusually fast, that the exhaust hits something under the truck- im sure i didnt mention some other things that i tried but these came to mind at the moment.

So as you can see im just about out of ideas

Any help would be awesome.
Thanks,
Joe

This worries me. Try a compression test and lets see how they come out. whats the coolant level like?

 

[turbojoe]

Well i checked to see if any fuel was returning, just to make sure its getting fuel and it is. it fills the the foot part of the 2L bottle after about 20 secs. of cranking.

Chevy, im about to do a compression test in a few mins.

thanks
Joe

 

[NemesisDP]

Take a can of dust remove and turn it upside down and spray a LITTLE into the intake to see if it will start. Then you might be able to scan it with it running. Rail pressure on mine was fine at cranking but at idle was all over the place found the wires to a sensor? regulator? staight down from the wireing harness(where u unpluggered the edge) had been eatin. Dam mice

 

[turbojoe]

Well its got compression 400 psi...:thumb: i looked at the harness and couldnt see anything, you said the fprv wires were eaten? they go from the sensor straight into that plastic harness cover... and the wires are not chaffed at the bale connector.

 

[Chevy1925]

all 8 400+?? id be lookin at changing the FCIM with a known good one

 

[turbojoe]

I did change the FICM with one of our trucks and still nothing

 

[Chevy1925]

I did change the FICM with one of our trucks and still nothing

Ah didnt see that above. Stock tune? did you try changing ECMs?

 

[turbojoe]

i havent tryed ecms because i dont have an 03-04 truck to try it with.

 

[dmaxvaz]

see if grubb or toman has a spare 03-04 ecm

 

[turbojoe]

well she magically started:woott:. i unplugged the FRPV and cranked it a couple times and she stumbled and smoked then ran rough and didnt rev. then i shut it off and plugged it back in. then it ran ok and revved but was still kinda rough for about 10-15 minutes driving it around. and the balance rates were all over the place some where -7 and some were +15. but then it smoothed out and so did the balance rates back to normal....

Maybe the regulator was stuck or something, cuz he said he put some weird additive that i never heard of and it made it stick???.

So i put two quarts of ATF in it and drove it for about 2hrs. and it hasnt hicupped or nothing.

It does seem to have a little bit of pressure knock cruising but rail pressure is normal.

Anyway giving it back tomorow and we'll see how it goes.

thanks,
Joe