So I began to notice a strange event occuring about 5% of the time that I floor my car.

My cars drives beautifully in every single way...but once in a while, I will be on the highway at around 50mph, drop it into 3rd, floor it and there is practically no acceleration at all. Once I take my foot off the gas however and quickly floor it again, it comes right back to life.

I am trying to figure out as to whether or not this is clutch slip, the ecu adjusting timing or something else along those lines.

When clutches slip on these cars, does the engine not rev as normal? Kind of how you can't really rev our cars if you drop it into nuetral at highway speeds and give it some gas.

It should be noted that I have tested the clutch by giving it full throttle in 5th at 2500 all the way to 4000rpm and it holds solidly.

No CEL's are tripped and the car drives perfectly once I get back on it the second time.

So any ideas as to what this could be? Has this happened to any of you?

 

You have an intake correct? It could be a misfire but not a big enough one to throw a CEL.

 

No intake. I am 100% stock other then a Trifecta tune.

 

It is likely the tune or the ECM in that case. Do you have another ECM?

 

Ya what he said, sounds like you're having this problem (where throttle input is not always at 100%) and the resolution in this case was a new ECM:

Clicky

 

I get a clutch slip around 3 grand that seems much more pronounced in 3rd gear than 4th or 5th. I know it's the clutch because the revs jump up a bit and then fall back down while the acceleration stays linear.

It happens while accelerating though, not immediately upon WOT. It doesn't feel like a hesitation as you describe.

 

Well this is actually my spare ECU which is tuned..I have the original one with the stock tune.

I'll do some testing with both of them.

 

In the link I provided the faulty ECM was also the tuned one...I find it hard to believe it's coincidence if this turns out to be your problem.

 

Flashing an ECM can fry it sometimes. The heat from underhood temps can also ruin an ECM. I have flashed my ECM more times then most will ever do with no issues though.

 

That's what I was getting at, not that the tune itself was smoking it . Like any chip improperly connecting/disconnecting the tuning unit when powered or writing a flash chip can ruin it in a heartbeat.

 

His tune could be causeing a rich misfire as well. When you quickly down shift and hit it like that sometimes the A/F will go even richer than commanded as the turbo spools and that can cause a misfire.

 

hey man if you want to we can take a look at it sometime soon i'm actually in ct this week.. but when i get home we can look into it ..

 

I think you are on the right track. That would make sense with the behavior of the car.


PM'd you.

 

Did you figure it out?