help! tech question

[mustang2105]

will having air in diesel fuel system cause the starter not to crank fast enough?? Reason i ask is because i changed a injector pump on a 7.3 IH engine once and after it would crank so slow with brand new batteries. I thought starter was bad so i bought a new one .Same problem. I changed cable ssame problem. I went ahead and decided to crack the injector lines . I cracked the started over and then it worked right. Someone told me air in the fuel line wouldn't affect the starter but i think i'm having a similar problem with a Bobcat. let me know if i'm right or wrong.

 

[jimmer2880]

I know that ignition timing on a gas engine will effect cranking speed/ability. I imagine the same thing goes for injector timing on a diesel.

EDIT:
Sorry - just re-read your post. I have no valuable info (as usual).

 

[Soundguy]

Since the injector is sealed till it pops off.. the cyl shouldn't see any difference in anything ahead of that injector tip anyway.

I've seen people run a diesel off wd-40.. heck.. I've started/ran a 353 detroit on wd-40 long enough to figure out the fuel pump was bad.

IMHO.. air int he lines was NOT effecting your starter

soundguy

 

[JB4310]

From my little experience running Ford tractor fuel tank empty,
before I could get the system primed I tried to get it turning with ether. That bound it up and it cranked very slowly, like the battery was run down, making it even harder to get going.
Had to pull it with another tractor to get it started.

Were you using stating fluid?

 

[Donsyl]

Hey Mustabg, if you have air in the lines, you can crack them open and see if you have a manual hand pump and bleed ouut the air. Now for the starter, the air in the lines, if you have any, will not make the starter slow. i dont know about all diesels, but is the timing on the engine that your working on get timed by the injector pump? I know that i had a cummins 4 cylinder on a piece of equip. and you could move the inj. pump and change the timing, change the way it ran.........just a thought...good luck....Don