6.9 misfire at higher rpm

[6.9idi_sam]

Hey guys I just installed my facet pump got it running drove it around for a day and now I have a misfire at higher rpm. My injection pump is turned up some could that be the cause? There's no leaks anywhere.

 

[jwalterus]

what pressure and flow rate are your getting from the facet?

 

[icanfixall]

No simply turning up your fuel wont cause a high rpm misfire. Now tell us at what rpm is this misfire. Also tell us how many miles are on the injectors and the injection pump.

 

[6.9idi_sam]

Facet is doing 11. Probaly about 45k on injectors and pump all remained installed by ford. Truck runs fine and starts fast and ran fine yesterday all day.

 

[6.9idi_sam]

I feel like it advanced the timing

 

[79jasper]

Yeah, but I would bet money on a wot run you are dropping pressure like crazy. Like a air leak or restriction somewhere.

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[6.9idi_sam]

Also to add my truck doesn't have a rpm gauge

 

[6.9idi_sam]

What else would it be? My return lines are less then a year old.

 

[IDIoit]

could be a valve spring issue?
weak lazy valve springs will cause premature float and can be mistaken as a miss.

 

[6.9idi_sam]

No I don't think so. My engine is really healthy only has a 116k. My friend told me his dura max did the same thing when he did a bigger cp3 said it like backfires and runs like **** then cleans up if he like brake boost which is what do to clean mine up

 

[6.9idi_sam]

Whenever it's doing it it blows white smoke with a bit of a blue to

 

[6.9idi_sam]

The injectors are old like 20 years they just don't have many miles

 

[IDIoit]

comparing your navistar to an isuzu could be the issue.

i seriously would be looking at the valvetrain.

but i dont know jack.

 

[6.9idi_sam]

I'll probaly need to do some injectors. A couple of them are oily around the caps. It has to be injectors I don't know hat else it can be. There is like a ticking noise at lower rpm

 

[Agnem]

I doubt your problem is valve train. This is more typically due to an injection pump problem, however it could also be injectors. The smart way to approach it would be to get your injectors tested, and if they are good, then get a pump. But I can tell you that your injectors will not likely be perfect, and the money spent to test them at 45,000 miles is a poor investment, since IF they do find a bad one or two, and you choose to replace it, you will be out the cost of injectors and a return line kit. The best return on investment with these trucks any time there is a fuel system issue, is a new pump and injectors all at once. That way, you get your 100K out of a matched system, and it doesn't spend the next decade nickle and dime-ing you to death.

Any time you turn up your fuel, you do divert fuel away from the advance circuit, retarding it slightly. You could try activating the cold advance with an alligator lead and running it that way to see if your problem goes away.