Power loss

[smplone]

2010 - Off Road
65k miles
Most recent upgrade (3 months ago) - BullyDog Tuner with WOT restriction off and adjusted idle.
Reason for purchase of bullydog - idle was extremely low (550-600)
Average 20 miles a day on flat ground
Average top speed between 60-70mph


- About a month ago started noticing in up hill situations & 4LO hill climbs; significant power loss. Truck is shifting to 3rd gear automatically to maintain 60mph up a hill with 0 payload. Typically a depression of the
O/D would be all that is needed. But now 3rd gear to make it up highway inclines. Same goes for off road up hill applications. Gas pedal can be on the floor and truck is not reacting.
Any thoughts? places to start looking into?
- Also have noticed in situations where truck is turned off and on quickly or on double starts there is a hesitation to stay on. Almost like it stutters to start up. Stepping on gas does not improve situation until RPM's get above 1k. Immediately following depression of gas pedal idle drops to 650 range until bullydog kicks it back up to 750-800.
- One thing to note is plugs and wires have not been changed in truck, currently 65k miles and on my to do list.

Any thoughts? Places to start looking? Recommendations on plugs, wires for street/off road use? Anything additional that should be changed when performing this service?

 

[J Everett]

Well, we have coil on plug ignitions, so you don't need spark plug wires. But it sounds like new plugs would be a good place to start. Other things that could be leading to power loss like that are faulty ignition coils, stuck injectors, a failing fuel pump (unable to maintain proper fuel pressure), a faulty fuel pressure regulator. Could be oxygen sensors. And one more thing I would check is the two camshaft position sensors. Those will cause all kinds of screwy things to happen when they start to go bad. And they are a royal PITA to change. But at least they're fairly cheap.

65k seems too little mileage for tune-up related issues (plugs, O2 sensors, air filter, etc.), but you never know. Even if you don't have a check engine light on, there may still be some diagnostic trouble codes that can be checked with a code scanner. That would be a good place to start.

Out of all of this, my best advice is that you find the fault of the problem and fix it before you attempt to alter the engine output with your new Bullydog tuner. There's definitely something wrong, it's not necessarily one of the things I listed, and a tuner is only going to band-aid the problem or exacerbate it.

 

[TJTJ]

Re-set the bully dog to defaults and/or go back to OEM settings and see if it affects the problem.

Job #1 is to see if the ECU is playing nice with the tuner, and make sure you're not chasing your tail on fixes.

 

[smplone]

Thank you for your time and responses. I wanted to jump in somewhere last night and see if I could find something. So went ahead and changed out spark plugs as this would allow me to look at multiple areas in one shot. Attached are the pictures of
my findings. The spark plugs are laid out in the order they were resting if you were looking in engine bay from front. I don't know much about intake / spark plug deposits. but the plugs appear to have a white haze around them, several of them had oil residue in threads. One of the plugs itself had oil on outside of plug. Most of the ports had oil shown near top. Out of the shafts I could see there looked like a lot of black gunk / deposits in bottom where spark plug ignites.

Next steps I want to look into is cleaning the throttle body. Research isn't really explaining proper procedure for this service. Remove Tb assembly and clean OR turn key to ON position, press gas pedal to floor to open TB and clean with engine off OR spray cleaner with engine on while working throttle. next comes the question of needing to perform an idle relearn after any cleaning. Lastly there are threads about using Seafoam over TB cleaner.

Thoughts?

 

[metzican]

Another thing to look at is the mass flow sensor and the air filter. I saw this similar stuff on tom's truck while at went he cleaned it up and poof full power.