rough idle/ slight skip with new injectors

05lonestar

05lonestar

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Jan 7, 2008
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hey guys, serious question here. i just recently installed a set of flux 3's and the truck literally runs like garbage when the engine starts cold. this is the second set of flux's that i've gotten. the first set had a cracked injector body. this set once the motor warms up, seems to idle fine but you can still feel a pulsation at idle or under a load between 1200 and 1900 rpm. is this a normal thing? i was told to check the crossover tubes and i did find a slight flat spot on one of them which i will be replacing on monday when cummins is open, but as for the remaining problem. my rail pressure seems to be normal. i am running only a smarty s06 with the tnt/r program with the setting on 3 for injection timing for larger injectors and power level on 9 and rail pressure set to 1 for stock. when it is back to stock, it runs worse. these injectors according to don were tested fine before they were sent back to me. i am running a stock cp3 with a t&c wild rail. i completely flushed everything before i installed the injectors. any feedback would be greatly appreciated. rail pressure on startup from being cold is usually between 6 and 8kpsi, and i never see pressures over 22kpsi.
 
I installed flux 2's last weekend and my truck does the exact same thing you describe. I installed new connnector tubes and my rail pressure is fine runs great when warm. It has a rough shaky idle and goes away quickly if I drive it down the driveway. Maybe others can comment if this is normal???
 
no, this does not sound normal. Don's injectors should idle super smooth -- much smoother than a stock set. If the new connector tube doesn't fix the problem, get them back to don.

-jp
 
For sure not normal, a set of Don's 5's idled smoother than when the truck was new.

Your sure there isn't a mechanical issue? I take it the truck was idling normal before the swap?

The obvious check lash again, make sure one didn't get too tight.
 
Joesixpack said:
For sure not normal, a set of Don's 5's idled smoother than when the truck was new.

Your sure there isn't a mechanical issue? I take it the truck was idling normal before the swap?

The obvious check lash again, make sure one didn't get too tight.
Click to expand...

i'll recheck the lash, just did it after i took the defective set out due to the bad injector filling my crankcase full of diesel. just so you guys know, our crank cases can hold 9 gallons of fuel..... at the expense of a turbo. the stock set i have idles fine and never made the skipping noise. i have a buddy of mine who is going to hook up his scan tool and cancel each injector individually to see which one it may be causing the problem. this whole thing would be so much easier if there was a way of getting ahold of don m directly. i've had scott from massdiesel as my middle man throughout this whole issue and its a pain in the ass.
 
Same problem with my truck since the install of my flux 3s.. I have been meaning to look at it. Its really rough in the morning and lobes bad.. Goes away once its warm but it still has a little shake every few revs at idle.
 
Yup.. keep us updated on what you find out. I ordered mine through Bob Wagner so I may be pulling these and sending them back to Don so he can check them out.
 
well just did the scan tool thing with the injector cancelling and found the #3 injector to have no change on idle. gonna pull it and put a stocker back in just to see if its the injector itself or what. also gonna recheck the valves and stuff and make sure lash is good and everything. if thats all good, this will be the second set within a month that's gone back to don.

speaking of that..... Mr. soup nazi, you have any opinions before i send these back to you again?
 
05lonestar said:
well just did the scan tool thing with the injector cancelling and found the #3 injector to have no change on idle. gonna pull it and put a stocker back in just to see if its the injector itself or what. also gonna recheck the valves and stuff and make sure lash is good and everything. if thats all good, this will be the second set within a month that's gone back to don.

speaking of that..... Mr. soup nazi, you have any opinions before i send these back to you again?
Click to expand...


Not sure what size of nozzle's yours has but I would have swapped #1 with #3 so that they were still flow matched...for example a stocker on one cylinder next to 5 of Don's 5's is going to still idle funny.


It could be a tweeked solenoid, I think thats something that can slip by diagnostics if its not actually in a engine.
 
well i took the #3 out and put the #1 in place of it, then took my stock injector and swapped nozzles and reinstalled it in the #1 along with the new crossover tube that i found the flat spot in and it seems to run much better now. i also noticed that the injector body he had replaced that was cracked from the first set was completely wiped clean of any serial numbers and the nozzle was engraved with the number 5. i still think t here is something fishy going on here. my buddy took video of a before and after. i'll post the link as soon as he gets it posted up on youtube.
 
Joesixpack said:
Not sure what size of nozzle's yours has but I would have swapped #1 with #3 so that they were still flow matched...for example a stocker on one cylinder next to 5 of Don's 5's is going to still idle funny.


It could be a tweeked solenoid, I think thats something that can slip by diagnostics if its not actually in a engine.
Click to expand...

i was forwarded in an email that these injectors he sent me back were actually tested in a truck...........
 
My 3.3's do the same thing..... How long is the turn around from Don running?...anyone know?
 
After all the back and forth on this I think the best thing for all involved would be for you to reinstall your stock injectors and send us the Flux 3's for a refund.

We cant see eye to eye on this and we certainly dont want any "bad feelings between us"
 
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