Loss of power
05-29-2017, 11:10 PM
#1
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Loss of power
i have an 06 with the 5.4 and while accelerating it has a loss of power until about 4k rpm then about normal until it shifts. The cats were replaced around November plugs and k&n filter in august. I just changed fuel filter and cleaned the air filter and still has the problem. Anyone have any ideas?
05-30-2017, 06:39 AM
#3
Mark
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Clean throttle body and MAF
05-30-2017, 10:39 AM
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There are no codes the tune up was in august no coils ill try cleaning the boots and i cleaned the maf and throttle body last week and it made no difference. It idles fine not missing but under load its sluggish.
05-30-2017, 01:53 PM
#5
Where are you located and when did it start?
My initial thought is the IMRCV, is it functioning? Here is a video where you can see it. It is behind the manifold and there is a control box for it.
There's "two" sets of runners in the intake, one is longer to give you more TQ and the other is shorter for more power.
Are there pending codes?
My initial thought is the IMRCV, is it functioning? Here is a video where you can see it. It is behind the manifold and there is a control box for it.
There's "two" sets of runners in the intake, one is longer to give you more TQ and the other is shorter for more power.
Are there pending codes?
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05-31-2017, 01:12 PM
#8
05 5.4l 3v s.crew lariat
misfires don't throw codes until they are really bad
Boots have to be replaced no matter how they look .If the tip area of the plugs in the cyl are not cleaned out with carb cleaner it can and does break some new plugs going in . Think about it , it breaks plugs coming out and you are going to force new plugs thru it .
This engine unforgiving if plug circuit not first class . Use OEM plugs ,put a small amount of dielectric grease on the ends of new boots-- it keeps moisture out . Tracking of high volts a big problem , the boots are the only thing stopping the 30,000 volts from jumping to the heads .They go bad with time and heat/oil .
Keep your hands and plugs clean ,anti seize is not necessary on new plugs , if you do use it be careful as it will cause tracking .Too much on threads can cause loss of spark return to head , I use a very small amount there . Use only nickle anti seize ,definitely not copper on alum heads ---bad reaction .
Use a torque wrench on plugs 25 foot pounds . Don't go by feel and do use a spark plug rubber socket . Don't be one of those guys dropping plugs into the well . Start plugs by fingers , these are alum threads --be gentle .
If you don't do this right you will have misfires and can ruin cats , as well as spend a lot looking for problems .
Clean all cop contacts as well as the connection plug . Use oem cops but they don't go bad very often .
This engine unforgiving if plug circuit not first class . Use OEM plugs ,put a small amount of dielectric grease on the ends of new boots-- it keeps moisture out . Tracking of high volts a big problem , the boots are the only thing stopping the 30,000 volts from jumping to the heads .They go bad with time and heat/oil .
Keep your hands and plugs clean ,anti seize is not necessary on new plugs , if you do use it be careful as it will cause tracking .Too much on threads can cause loss of spark return to head , I use a very small amount there . Use only nickle anti seize ,definitely not copper on alum heads ---bad reaction .
Use a torque wrench on plugs 25 foot pounds . Don't go by feel and do use a spark plug rubber socket . Don't be one of those guys dropping plugs into the well . Start plugs by fingers , these are alum threads --be gentle .
If you don't do this right you will have misfires and can ruin cats , as well as spend a lot looking for problems .
Clean all cop contacts as well as the connection plug . Use oem cops but they don't go bad very often .
05-31-2017, 10:13 PM
#9
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At idle and even flooring it it isnt the slightest bit rough. I did use a scanner and looked an the throttle percentage and at wide open throttle it was only showing 75%. There are no codes or pending codes.
06-01-2017, 12:27 PM
#10
You can try to turn your key on(don't start truck) slowly depress gas pedal fully then snap back up. Do this two or three times and see if it drives differently(probably won't), but I would def check those runners. One set is for down low TQ and the other is for higher RPM, it really sounds like they are not switching hence it has power from about 4k and up.
