The Power of Your ECM and Engine Sensors

[sealandsky]

A few weeks ago I posted about how my 2019 Yukon SC560 had rough and jerky low speed response, so I cleaned the MAF and Throttle Body (see post titled "Big Jerk"). My low speed drive-ability improved quite a bit, but my high end was a bit "off" from where it should have been. After seeing the amount of crap built up in my TB after only 14,000 miles I decided to also perform en engine "top-clean". Since I'm inherently lazy I asked my local service garage what they would charge me to perform the intake system cleaning while they were changing my Mobile 1 oil last week. After looking at me like I had two heads, they informed me that what I needed was a fuel system cleaning. I replied "just change the oil". So yesterday I went to the auto parts store and purchased a can of "CRC Intake & Turbo Cleaner" and convinced my wife to be my partner and throttle jockey (someone has to run the gas pedal while the other is squirting the stuff in the TB). After completing the somewhat detailed process I took the vehicle for the required 10 minutes of highway driving. While it immediately felt like there was more power on tap, the "check engine" light was on and light power application introduced a neck snapping hesitation & jerk. After returning home I performed the magical act of touching the positive and negative battery cables together for about 20 seconds, reconnected and went for another test drive. No low power jerking and check engine light extinguished. Wow - What a difference the top engine clean did! The lack of crap on my intake valves and a clean intake system appear to have allowed the engine sensors to provide more advanced timing and the power recovery has to be at least 25 HP (If less I doubt I'd feel the difference). I was also getting lower gear upshifts at 6,000 RPM (maybe more but the gauge quits at 6,000 and the rev limiter was not kicking in at 5,900 like it had been, it must be somewhere over 6,000 now. From a lot of digging on the subject, I've learned that to keep your direct injection engine performing at it's best, the top clean (and TB / MAF clean) should be done about every 10K miles. A supercharged engine perhaps even more often. This also strongly makes the case for a "catch can" which I'm still researching and intending on installing as soon as I'm not too lazy. It's like I bought a new truck!

 

[Joseph Garcia]

Thank you for reporting your work and results on this. Knowledge is power.

 

[hcvone]

I don't drive my callaway Tahoe that often, only have about 5k on it, but everytime I take it out it runs fantastic, it's by far the slowest thing in my garage, but pretty fast for a SUV. I also put a bottle of Techron fuel system cleaner in the tank every 5k miles, per my gm tech, been doing that for a long time

 

[sealandsky]

I don't drive my callaway Tahoe that often, only have about 5k on it, but everytime I take it out it runs fantastic, it's by far the slowest thing in my garage, but pretty fast for a SUV. I also put a bottle of Techron fuel system cleaner in the tank every 5k miles, per my gm tech, been doing that for a long time

The Techron will help keep your fuel injectors clean and I may try that as well. But Techron will do nothing for your intake valves (and the innards of your supercharger). You might consider the intake cleaning on your other direct injection vehicles that have over 10K miles.

 

[sealandsky]

Thank you for reporting your work and results on this. Knowledge is power.

Next time you have a little spare time on your hands, give it a try.

 

[GreyStone]

It seems unusual that your fuel system would be that filthy this early in the service life of the vehicle...are you using the stock style paper air filter element or some type of "high flow" performance filter?