Approximately a year and a half ago I purchased an SCT X4 tuner for my F150 ecoboost. Shortly thereafter I purchased a 91 octane performance tune from 5 Star Tuning. Love the tune. Within the past month I have developed a problem with my truck and this tune. When I accelerate from a slow speed, I hear the Blow off Valve continually releasing pressure. Occasionally I will hear a heavy knock or pop and the truck seems to act like its flooding. Eventually the RPM will get high enough for the problem to go away. I will see heavy black smoke coming form the exhaust as the problem is clearing up. I have monitored the boost pressure using my X4. The boost seems to build up almost immediately after I push down on the gas. I'm talking 14+ psi almost immediately. ON any other tunes the boost takes a little time and RPM to build up. I don't have any problems with me MPT 87 octane tune and the canned tunes. I am curious if anyone else has had a similar problem. If so, what was the fix. I love this tune and want to get it installed again.

 

The fix is to contact 5 Star.

 

How many miles on the plugs?

 

I'd recommend talking to 5-Star too. But, tunes don't "go bad". Something in your truck has deteriorated. The plugs are one possible source of the problem, but there are others.

Are there any codes?

- Jack

 

Tunes can certainly get corrupted. The reason I suspect this is it runs okay on his other tunes.

 

31000 on the truck. Plugs replaced 500 miles ago. .28 gap. I was thinking it was something other than the tune as well

 

A tune can certainly not load correctly, but once it has loaded properly, would you say it's likely to change during its stay in the ECM? From his original post, I was inferring he simply used the 91 octane tune constantly since he liked it so much and that he only tried the others when he started to experience difficulties.

My experience with programming tells me that programs are very stable unless corrupted by some outside influence or unless they are "buggy". but, if they're buggy, they tend to misbehave in predictable ways, that are determined by the bugs. In the case of a program in an ECM, I don't think it gets changed by outside influences, and, I suspect a bug would show up rather quickly during its loaded residence.

But, gradual degradation of the myriad sensors in modern trucks as well as changes to other components might just create conditions that could not be handled properly by a tune that "pushes" things to maximum performance.

Now, if he's constantly changing from one tune to the other, I agree, there could be a "tuning problem", and it could have any number of causes.

- Jack

 

I have the knock/pop too. It will do it on the stock tune and the 5* 87 tow-performance tune. I changed the plugs to new Motorcraft gapped to .030" and there's no real change. Mine only does it when I get hard in the throttle. Strange thing is the 5* tune sets off my laser detector but the stock one doesn't. I suspect one of the solenoids that control the wastegates is doing something different on the 5* tune. They are controlled by the PCM and a tune could change their behavior.

 

FYI- on a boosted engine this is potentially very dangerous situation that could easily cause piston failure, etc......IMHO, put it back to the stock tune.