Dies when warm

[MMeier]

Friend is working on a 2004 (305HP) that runs fine for about 2 miles when cold. As soon as it starts to warm up , the thing will die on him, replaced LP, filter, checked air filter while he was at it also. No codes stored or thrown. . any ideas ?

 

[HOBrian]

Does he have rail pressure gauge?



The over flow might be stuck open or when warm opens up and stays open??

 

[cerberusiam]

Check and re-torque the cross over tubes.

The over flow might be stuck open or when warm opens up and stays open??

What overflow are refering to? The only bypass is in the COV which is spring loaded. Is that what you mean? Thats possible but don't think have ever heard of a COV completely failing like that.

 

[MMeier]

No RP gauge . Anything related to the FCA perhaps, I threw him my spare one to try out , but haven't heard back as of yet . ALso was thinking it could be something PRV related ?l

 

[cerberusiam]

ALso was thinking it could be something PRV related ?l

Possible, but thats expensive to test along with FCA and COV. Four people on 2 different forums have solved the same problem with a re-torque, free.

 

[MMeier]

I'll tell him about the retorque also. They have never been apart before, though. Guess I could loan him my rail cap too to try out .

 

[cerberusiam]

They have never been apart before, though.

Two of the people I talked to had unmolested trucks also. Thought it was weird that would happen but the re-torque solved the problem. The others had 5-15k on replacemnt injectors and they loosened also. On at least one it was minimal tightening on only some of the tubes and it solved the problem.



Dunno, a place to start I guess.

 

[JJPage]

At 7k miles on new F1 injectors, 60 miles from my house with few tools, my truck decided to die, just as if I turned off the key, then would re-start and die, again over and over.



I was able to limp into Dave Smith Motors in Kellogg,Id. No codes, all sensors tested ok, but when they did an injector return fuel measurement, it was way high (240ml@60sec, I believe), they were sure I needed all new injectors... .



To make a long afternoon story short, we decided that they would check the torque on my cross tubes, all were loose. After a re-torque, a 6 hr visit and $200. 00 dollar bill/invoice(which I thought was very reasonable), We were back on the road and not a single occurrence since. That was about nine month's ago.



Prior to that day, it had stumbled a few times,rail press drop to 2/3k, but would quickly recover. I had already checked and replaced several components(fca,cov,rp sensor,lift pump,rprv,injector harness,removed ez/tst) I was at my wit's end, thought about cross tubes, but never checked.

 

[MMeier]

Well, it wasn't the FCA, acted the same with my spare in there. I'll look up the specs on the tubes and tell him . Keep the ideas coming !!

 

[JJPage]

Well, it wasn't the FCA, acted the same with my spare in there. I'll look up the specs on the tubes and tell him . Keep the ideas coming !!

37ft lbs on the cross tubes.

 

[cerberusiam]

37ft lbs on the cross tubes.

Yeah, what he said.

 

[MMeier]

I'll relay the info !

 

[MMeier]

Ding, ding, ding...

... we have a winner !!! Crossover tubes it was !!! 3 were basically finger tight, including #4 which just had its rail to tube line replaced at the "dealer", hmmmm, have to wonder here a bit Thanks for the help once again guys !!! Oo.

 

[Prairie Dog]

Why do loose crossover tubes cause this? I can see them leaking and maybe causing a miss or even a knock but I can't see why it would just die. Can someone educate me?

Thanks,
Scotty

 

[mini14]

excess fuel return

 

[MMeier]

Does the fuel go through the return system, or leak into the crankcase ? Wondering myself.

 

[mini14]

afaik its going to return the fuel to the tank, or youll c wet tube nut on the head

 

[SRadke]

Through the return system. Out the banjo in the back of the head and back to the tank, you'll never see it. Same thing can happen if you ding/knick a crossover tube pushing an injector in. Scar the surface and the fuel leaks by. Doesn't take much of a ding at 20k psi.

-Scott

 

[Rascal]

Could someone please explain exactly where and how to retorque the crossover tubes.

 

[JJPage]

As you look at the injectors, where they go into the head, you can see the retaining nut under the injector line nut.

To re-torque, remove the injector lines, intake horn. torque the retaining nut to 37ft lbs, #6 is a pain, have patience. You will want to hold the retaining nut stable with a wrench while re-installing the injector lines.

The reason the truck dies with loose tubes, is it cannot maintain rail pressure high enough to fire the injectors. If they leak long enough, new cross tubes may be necessary, that high pressure can carve a groove through the seat surface of the tube, and they will not seal.