1984 6.9 fuel not goin from ip to injectors

[riphip]

Don't get snakebit out there in the weeds

 

[IDIBRONCO]

Might be a dumb question, but could it be off a Chevy and not for a idi? I thought I read on here that they run the opposite direction. Am I off in the weeds here?

It can't be off of a Chevy. Even if a GM one would bolt up (I'm not sure that they would physically interchange), the injector line fittings are bigger on both ends of the GM lines than on ours. That's going out on a limb and assuming that the 5.7 uses the same style of lines as the 6.2/6.5. Also the flange that actually fits against the gear housing is triangle shaped on the GM pumps while it's round on ours. You can't confuse the two. I'm thinking that with the return line off of the top of the injector pump, then some fuel would come out of the lines on the injectors "backwards" towards the injector pump while cranking the engine over. When all of the return lines are attached, it's a closed system. The excess fuel that comes out of the injector pump would make the fuel go in only one direction, away from the engine toward the fuel tank. When the system isn't closed, the fuel could go in "all" directions. Another example would be a round of ammunition and a gun. If the round is exploded out in the open, then the force of the explosion will go in all directions. If fired inside the gun like it was designed to be, the force of the explosion will only go out the end of the barrel. There's A LOT of difference in pressures here, but it's the best way that I can describe it.

 

[84f250]

So I got another pump from a better know place, got the other one returned thankfully. but it still won’t fire, and pretty much fuel isn’t goin into the new ip and just backing up and running thru the return lines, iv checked and tested everything fuel related but still won’t get anything at injectors, I’m not sure what else it could be ?

 

[Thewespaul]

Do you have an electric fuel pump? It could be possible you have too much inlet pressure and it’s siezing the head

 

[84f250]

It’s not electric, the original tank has a good gash in it, so I have it running outta a diesel can on the side of the truck, could that be causing issues ?? This is my first 6.9 so I don’t know to much about them. The can is completely full and the line is fully submerged

 

[Thewespaul]

Can you post a picture of your setup?

 

[84f250]

You must be registered for see images attach

 

[84f250]

That can is just hooked up to the pump on the side of the motor ? But shouldn’t it work fine ? Like on gas trucks ?

 

[Thewespaul]

Cool buggy. How much cranking have you done? Do you have a tach to see what rpms it’s cranking at? Should work fine with that setup

 

[84f250]

It doesn’t have a tac, it cranks decent but maybe it just not enough? My 2000 7.3 did that once in the fall where it wouldn’t start but turned out the starter wasn’t doin a good enough job and thanks it’s my gf’s and now I’m hooked on vw’s lol

 

[84f250]

It’s pushing fuel fast tho all the way to the ip

 

[Thewespaul]

You may not be cranking fast enough, pull all the glow plugs out and crank it, it will spin over freely and you should get fuel then. Its like taking spark plugs out of a gasser

 

[IDIBRONCO]

Off topic, but what kind of three wheeler is that? It looks like a 110/125m, but it's hard to tell. I haven't seen a hitch like that before.

 

[84f250]

Okay I’ll try that and I have a two 85 handas lol ones a 125 and ones a 200

 

[IDIBRONCO]

Cool. I have one or two (maybe more) myself. I was just riding one earlier today.