running rough at light throttle

S

solow1k

New member
Joined
Apr 22, 2007
Messages
253
No matter what speed im at at 10-20% throttle it stumbles. If i give it more or less throttle input it will easily come out of it though. It's also much worse if you don't let it warm up, but to totally warm up it takes 10-15minutes of idling and some times still does it. Truck combo is,

2004 6.0, EGR delete, ARP head studs, new heads, Elite stage 1 injectors, suncoast trans, suncoast converter, innovative tunes, full MBRP exhaust with no muffler 3.5"dp to 5" strait pipe.

What do you guys think the issue is? I would think it would run pretty smooth with all these mods
 
I'm going to go with combustion in the fuel. Take the tune out so it doesn't spike the rpm. Then rev the engine slowly until you get to an RPM where the engine starts to shake. If it's shaking under 2000rpm get out some balloons. If its shaking like 2800 and up. Time to put some check valves in the high pressure oil pipes.
 
PSDPlayer said:
I'm going to go with combustion in the fuel. Take the tune out so it doesn't spike the rpm. Then rev the engine slowly until you get to an RPM where the engine starts to shake. If it's shaking under 2000rpm get out some balloons. If its shaking like 2800 and up. Time to put some check valves in the high pressure oil pipes.
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lol in none techy terms?
 
solow1k said:
lol in none techy terms?
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Put a bobble head doll on the dash. When the dolls head starts shaking. Look at the rpm on the gauge. You should rev the motor in 100rpm increases until the doll starts to shake like Michael J Fox.

Report back at what rpm that happens.
 
PSDPlayer said:
Put a bobble head doll on the dash. When the dolls head starts shaking. Look at the rpm on the gauge. You should rev the motor in 100rpm increases until the doll starts to shake like Michael J Fox.

Report back at what rpm that happens.
Click to expand...

and i assume to do this while driving not in park? Will check it out tomorrow. Also completely warmed up or not?
 
In park. Just need to rev the engine slowly to find the rpm where it shakes.
 
PSDPlayer said:
In park. Just need to rev the engine slowly to find the rpm where it shakes.
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Ok it seems to shake/miss through out the entire RPM range. But i noticed at 1200-1800rpms its the most noticeable, but never entirely clears up. Which means?
 
solow1k said:
Ok it seems to shake/miss through out the entire RPM range. But i noticed at 1200-1800rpms its the most noticeable, but never entirely clears up. Which means?
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Which means you probably have injector cup leakage. Time to isolate the heads and see which ones with blow up a balloon.
 
PSDPlayer said:
Put a bobble head doll on the dash. When the dolls head starts shaking. Look at the rpm on the gauge. You should rev the motor in 100rpm increases until the doll starts to shake like Michael J Fox.

Report back at what rpm that happens.
Click to expand...

Hahaha...you have such a way with words!


Does ford/IH sell the cups or is that a machineshop deal?
 
Ford sells the cups. Slide hammer them out with the tool and then pop them back in with some loctite on them.
 
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