Leaning out at full throttle around 50-70 MPH

[Mr. Hemi]

I have noticed that my truck feels like it is leaning out or running out of fuel under full throttle when it hits around 50-70.

Feels like it just is fighting to get more but not sure what it wants to do.

Anyone with a similar experience?

No boxes or changes other than putting a 4" hole with a screen over it in the bottom of the aircleaner box. Performed the same before alteration.

 

[ScottBrown]

check the air filter and fuel filter then get back to us

 

[Mr. Hemi]

Fuel filter was changed at 4000 miles, air filter the same.

I had "opened" up the air box to eleviate the filter minder showing restriction/too much vacuum. No restriction now.

Have noticed even with a brand new fuel filter.

Without a pressure gage may be difficult to tell if it is defueling or just out of fuel due to the lame stock pump.

 

[CLAYTON]

Add some more fuel or timing and duration and then the only lag is the time it takes you to put the peddle to the floor

 

[ScottBrown]

Just for grins check your intercooler hoseclamps and check for any wear on the rubber hose to the intercooler

 

[ChrisTucker]

are you sure its not the wastgate opening to bleed off excess boost? If you lay into the throttle for an extended time, 5-6 seconds, enough boost will develope to open the gate and release boost making it feel like it is leaning out.

 

[Big MAK]

... good ideas.



Also check fuel pressure. The lift pump in particular (don't touch the high pressure lines!).

 

[Mr. Hemi]

Every thing seems to check out other then the things I can hose leaks, air and fuel flow, but without gauges it is difficult to assertain what is really going on.

Most likely the boost issue is probably what it feels most like.

Hate to put a box on the truck and risk toasting the trans or something else.

 

[ScottBrown]

have you checked for any codes thrown, maybe something with the sensor in the airbox. just a few more thoughts thrown you way

 

[RRoton]

First thing you need to do is install gauges.

A boost gauge and a fuel pressure gauge might give you some very useful information when this happends.