Jump to content

Rough Running


Recommended Posts

Alright I got shims from work using their punch die set thing and did some other things like put in new copper washers and banjo bolt washers on everything. Upped the pop pressure from 220 to 280 (stock is 260). Well now it runs like crap. It just sits there and chugs. I have good fuel pressure and no fuel leaks. So the real question is, do I actually need holes in those shims? I'm thinking the fuel is getting past the edges of the shims and allowing it to run, barely, but don't know if it works like that or not.

--- Update to the previous post...

A video to entertain the masses. Think I might go ahead and take the shims out and see what happens. I didn't touch the injection pump so it couldn't be the culprit.

http-~~-//www.youtube.com/watch?v=pB6EqzZq6tA

--- Update to the previous post...

Well I got impatient and just took them back apart. I need this truck in the morning. Anyhow, the myth has been busted.

Posted Image

The return goes up through the center straight through the spring and everything. The OEM shim was facing the nozzle and the other shims were on top of it so you can see the intense pressure trying to push it's way out of the injector return line. Little more and it woulda put the holes in the shims for me lol. So why did it run rough! Return lines relieve excess fuel that is under pop pressure, so what exactly does that mean? What exactly is it's purpose..

Link to comment
Share on other sites

  • Administrator

It a bleed hole. Mine are the exact same design... The center hole vents out the side of the injector to the return rail. So basically you have trapped pressure on the upper side of the needle pressing it closed even harder than the spring hence its desire to stall. Kind of how the CR injector works.

Link to comment
Share on other sites

post-45-138698185378_thumb.jpg pics of one of the injectors I took out. Thats what 5 minutes of running looks like. Basically the same as after they've been in for 5 years, oddly enough. Difference is that all wipes off and its back to how I polished it looking, driving it and getting heat cycles into it cooks it on there. post-45-138698185388_thumb.jpgOne where it just blew through, actually was like that on two injectors. That's all 3, blew them all. 2 injectors had no marks on the shims whatsoever :cookoo:

post-45-138698185368_thumb.jpg

Link to comment
Share on other sites

×
×
  • Create New...