Bogging No Power

Robert Owner/Technician New Jersey Posted   Latest  
Resolved
Driveability
2000 Toyota Tundra SR5 4.7L (2UZ-FE) 4-spd (A340E) — 5TBBT4414YS026239
Bogging No Power
No Codes

OK so I have no history on above truck. other then a fuel pump and MAF sensor

This is what the deal is. it ill start up and idle with no issues. Put it in gear and it has just enough power to move If you feather the gas. 

No load I can bring engine speed up to about 2500 RPM Above that it will start to sputter and die. Sometimes pop through the intake

No fault codes at all

Timing has been checked and is correct. Yes On the correct marks not the"T" mark 

Checked cam and crank signals and are spot on with a know good image.

Both oxygen sensors are toggling as they should. Snap throttle and both sensors go rich.

Removed both oxygen sensors to check exhaust restriction and same result.

Installed vacuum gauge and have 18-20 In vacuum with a steady needle. As I open throttle needle drops as it should and stays steady when it acts up

Just checked both App and accel sensors and both are in spec. according to SI

What am I missing. This has a throttle body with a cable and a motor 

Every thing i have found suggests timing Looking into ignition now.

Thanks in advanced

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Gail Technician
North Carolina
Gail Default
 

MAF readings? Fuel trims?

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Robert Owner/Technician
New Jersey
Robert Default
 

Mass air flow is reading about 6.5-7 grams per second which is a little high. Fuel trims are around minus 4 percent

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JJ Technician
Massachusetts
JJ Default
 

I believe this uses A/F ratio sensors, not o2 sensors. Maybe someone can double check me on that. If so, they shouldn't be toggling at idle, also on the scan tool a lean condition should be high voltage, rich will be low voltage.

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Phillip Diagnostician
Alaska
Phillip Default
 

What are your fuel trims when problems happen? What are your fuel trims in gear with the vehicle stopped? Also what are your A/F sensor readings at idle in park and in gear stopped? Last what are the A/F readings while the problems happen?

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Albin Diagnostician
Washington
Albin Default
 

Take a look at the rear oxygen sensors. What is the voltage at idle, and when the problem is present? Since this engine will not produce enough power to drive, the diag process must be done in the shop. Is there any chance you can get some gas analyzer numbers? If not, you are going to need to rely on the oxygen sensors for this information. There is another place to look though, Capture some…

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Rob Owner/Technician
British Columbia
Rob Default
 

Fuel pressure and volume is?

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Jack Owner/Technician
Texas
Jack Default
 

What is the fuel pressure

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Lyle Owner/Technician
Virginia
Lyle Default
 

What is your fuel pressure and volume?

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Alan Diagnostician
United Kingdom
Alan Default
   

Rich is low voltage. and voltage is between 0 and 5. Won’t switch like o2 sensor Try giving it a rev and spray some brake cleaner into the intake at the same time and see if it revs up then.

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Jerry Manager
Massachusetts
Jerry Default
 

Check your fuel quality sounds like u have water in the tank !

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Steven Technician
California
Steven Default
 

Did we look into the Air filter Housing for uninvited guests? Fuel Pressure/ Volume

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Robert Owner/Technician
New Jersey
Robert Update
 

So it is a fuel deliver issue. If I spay brake clean in the intake when it start acting up it runs properly. I now remember why i did not do fuel pressure and volume. I can not get the lines loose under the hood. And there is no test port I can find. At least I know what direction I need to go.

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Glenn Owner/Technician
Texas
Glenn Default
 

We have found that removing O2 sensors to test restricted exhaust is not always a 100% accurate test. In cylinder pressure test would show timing and exhaust pressure? or at least back pressure .

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Guy Owner
Hawaii
Guy Default
 

How about a VE test?

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Jeff Diagnostician
California
Jeff Default
 

You said you checked the cam and crank sensors and they are spot on , I'm assuming you meant cam to crank alignment, But did you check the cam and crank waveform amplitude during snap throttle and during the sputtering event ?

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Mohammadu Diagnostician
New Zealand
Mohammadu Default
 

Check the fuel pressure

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Victor Owner/Technician
Florida
Victor Default
 

Try unplugging Oxygen sensor and see what happens..

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Alan Diagnostician
United Kingdom
Alan Default
 

As it’s had a fuel pump and maf sensor and assuming they are good oe quality then the condition and contents of the fuel filter would be high on my list to check. And if bad possibly the condition of the injectors Or fuel pressure and flow. Whatever is easiest to do first. Has it got a steel fuel tank and fuel lines?

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Robert Owner/Technician
New Jersey
Robert Resolution
 

Problem fixed. After finally forcing the fuel damper loose I discovered that some one installed the wrong seal ring on the damper side. I have a picture of old and new I will try to post.

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