So I've been having this rough idle problem since installing my Swamps 200/100 injectors. Injectors where brand new along with UVCH, motorcraft ipr and icp. My problem is once the truck gets up to operating temp it will have a slight miss at idle only. And is a little sluggish taking off. Hpop pressure is good. I've thrown so many parts at it trying to figure it out. Any help would be greatly appreciated!!

New parts,
IPR
ICP
ICP pigtail
CPS
EOT
MAT
Fuel pressure regulator on fuel bowl
Fuel filter
New optima yellow top batteries
New alternator
New flex plate

Upgrades
Swamps 200/100 injectors
Garret GTP38R turbo
Non-ebpv pedestal
Non-ebpv turbine outlet
Airaid cold air intake
John Woods Street Performance Trans
Mag-hytec all around
4.56 gears
Boost, pyro, trans, and hpop pressure gauges
Superlift 10" lift
40" Nitto Trail Grapplers

 

What and who are you using for tunes? This may all lie in the tuning you are running. Have you spoke to them and told them what is happening?

 

I am using swamps tunes that came with the injectors.

 

First, let me say WELCOME to FTE!!!

Second, it sounds like quite a nice build. We like pics

Third...oh yeah, your questions...

Have you done any intank mods yet? Hutch mod, replaced lines from tank to intake side of fuel pump?

The internals tend to break down, especially with ULSD they introduced after our production vehicles, and it sucks air.

It may or may not be the main cause of your sputtering, but DEFINITELY needs to be addressed. Injectors hate air.

Do you have a fuel pressure gauge? Strongly recommended. I currently have a post filter gauge, but am going to add a pre filter gauge, too. That way I can check the state and health of the fuel filter at any time- especially if there is anything unusual going on.

I'm not an injector expert, but from what I've read those are pretty large and require careful tuning to get them to "behave" under low load and idling. That all requires steady fuel, too.

 

I have not been able to do any in tank mode yet. I was thinking maybe the screens in the mixing chamber are clogged. I do not have a fuel gauge yet unfortunately so I can't monitor my pressure. And do you recommend anyone that makes a in tank mod kit?

 

I'm thinking that if it's a fuel intake problem it would be worse under highest demand, not at idle.

 

I didn't use a kit, just some SS line, union, 30R9 fuel line, and injector hose clamps.

Bent the line to shape, installed new pickup foot, eliminated the screens. Some nice writeups on here.

I have mine in one of my threads, but can't lay my hands on it at the moment, LOL

 

I'm thinking "air" not volume. If the fuel supply isn't dead-on stable, those big injectors are gonna cough and sputter.

Have you seen this video, emptying my tank with the fuel pump before the intank mod?


See all the air and glops of fuel delivery? I'm told the iPhones don't show the annotations which have the details.

I was horrified at how BAD the air and delivery was!

 

Forscan or Torque Pro or similar can help with some info, like a PERDELS test to show which cylinders are misbehaving. Time for some diagnosis to go along with all the new parts.

Sounds like it's going to be a fun truck once it's sorted out!

 

Very interesting and good point. Between this and that O ring in the hole I've learned some good things today.

 

But what is causing the air in the fuel line. Because this happens even when the tank is absolutaly full and the entire fuel sending unit is submerged. Where could the air be coming from?

 

The quick disconnect fuel fittings are sealed with an oring. That whole thing gets fatigued and allows air to get sucked in through there while drawing fuel from the tank, then BAM- the line gets sucked tight against the fitting and no more air....until the suction drops again.

This is why many of us replace the fuel line between the tank and the pump. Apparently the QD fittings are fine with pressure, just not as good with suction and air.

At least that is how it was explained to me

Then there is the duckbill in the tank...

 

Maybe a damaged injector O ring is culprit on the fuel side. Also doest it when warm, how's your compression #'s.

 

I'll have to check the injector o rings. Unfortunately I do not have the equipment or the money to do a compression test at this time. But I do know when I last had the compression tested it was when I first bought it and the shop said it was perfect.

 

Can I just replace the fittings? I would like to do a full fuel system upgrade but don't have money right now.