2000 yukon 5.3 falls on its face

[Tahoeyukondenali]

Garage kept radiant heated floor one owner prior to me it was a woman's vehicle but not her primary her primary was a 04 ctsv her husband owned his own business have all the maintenance records the oil changes was done at the dealership and other than oil and brakes the only thing ever done to it was a caliper was replace cause it stuck front driverside probly from sitting to long.

 

[rockola1971]

Right about 120k is the magic number for the fuel pump replace and tranny rebuild depending on how the vehicle was used. Does it ever take more than one engine crank to get it started or does it take 2-3 cranks by the key to get it started? Whats the engine vin letter on this 2000?

 

[swathdiver]

The wife's 2000 is a gutless wonder! It's running 3.73's with a tow package and only has 120,000 miles on it by far the least of any in the stable. It shows no codes runs fine except no power it don't miss sputter or stutter.

Cam lobes worn down or the cats are done for. Disconnect the upstream O2 sensors and make a short drive and see if she's got some pep in her step then. After that, run a compression test.

 

[Tahoeyukondenali]

Right about 120k is the magic number for the fuel pump replace and tranny rebuild depending on how the vehicle was used. Does it ever take more than one engine crank to get it started or does it take 2-3 cranks by the key to get it started? Whats the engine vin letter on this 2000?

T and no problems with fuel pump I swapped it and nothing changed

 

[Tahoeyukondenali]

Cam lobes worn down or the cats are done for. Disconnect the upstream O2 sensors and make a short drive and see if she's got some pep in her step then. After that, run a compression test.

Compression was 135 acrossed all 8 within a pound or 2.

 

[Tahoeyukondenali]

Compression was 135 acrossed all 8 within a pound or 2. Has almost 90lbs of oil pressure even when it is hot and Rollin down the road but hor is a loose term cause it barley warms up, temp gauge barely gets to 150-160 it takes forever to throw heat it barely blows lukewarm. Would it make sense that it ain't in the optimum operating temp range hence the lack of power?

 

[swathdiver]

Compression was 135 acrossed all 8 within a pound or 2.

It's not the lowest I've seen but what it good is that it's consistent across the board. Try the cats next.

 

[Fless]

90 psi oil pressure -- is that measured with a known good mechanical gauge? Way too high IMHO.

That engine needs to warm up. I don't know if it would help the power, but it would help the efficiency of the engine. Has the radiator ever been changed and, if so, to what mfr and part number? Thermostat? Recommend OE temp and mfr as thermostat quality varies and is generally better with OE.

 

[rockola1971]

90 PSI oil pressure, if thats a correct reading then something aint right there. They didnt have that kinda pressure brand new. Temp only gets to 150-160deg, if thats true then that means you likely are not in closed loop and are running rich. What do your spark plugs look like? Check the cats too! Measure inlet and outlet temp with a thermal gun. Should be close to the same temp. There shouldnt be a high temp on the inlet and a major low temp on the outlet of the cats.

 

[SnowDrifter]

Post a video of a 0 to 60 run at WOT

Pretty please?