Thread: Weird WOT experience

I floored it from a red light and kept my foot to the floor. I felt a strange shudder right before the gear shift. Kinda felt like power cut out, back in, back out and back in again over the course of about 2 seconds. Thoughts?

Maybe the rev limiter, torque management, misfires or the trans hates you.

Its too hard to say what happened. Now if you had a log/file of this happening it would be easier to pinpoint it.

Or fuel pressure is dropping off.

If it was 1st gear, that wouldnt happen unless his pump is weak.

Fuel pressure drop off from what I remembered was 10-12+ seconds of WOT.

That's what I'm saying. The pump could be dieing. Mine would shudder right before it shifted into second.

I wouldn't doubt the pump... I can do it again tomorrow with the scanner hooked up, what am I lookin for?

Fuel pressure.. So go get a fuel pressure tester/gauge and measure it

I'd monitor

Fuel pressure...which is manual
Timing commanded
Actual timing delivered
Knock Retard
Calculated torque (trans)
MAF
TPS
RPM
B1 S1 O2
Speed

I'm thinking it's torque management or KR off the cuff. Might be fuel. Tough to say for sure.

I've scanned pretty regularly and my KR issue is at low rpm tip in... Non existent at WOT. I saw 2* at third gear shift one time, months back.

Fuel pressure gauge... Something like this work? http://www.harborfreight.com/fuel-in...ter-92699.html

That should do it

Now, torque management. How would I know if this is what was causing it? And if it is torque mgmt, it's nothing to stress about then? It felt pretty not normal

Well..TM would induce KR to remove timing and back you down. TM kicks in with various torque levels, abusive behavior etc etc. TM is usually induced at shift points to keep you from full power shifting.

Cool. Informative. Thanks bill

what bout traction control?

It's a Park Ave

I've got traction control and it was on actually

So this happened again and worse. I pulled next to a gxp at a red light and floored it. Not exactly sure what happened when, just know that something is wrong. I think I wa doing about 45 when it started. Its a bad shudder/vibration and performance loss. Its been running pretty good under normal driving conditions. I'm going to pull the front three plugs after the engine cools an then the back three tomorrow afternoon. Just to rule out piston damage. I'm also using oil with no visible leaks.

My car did this everytime at the top of 2nd gear.

It would shutter with powerloss/cutoff and then come back.

Thats because i was seeing 7* KR.

That could be your issue also, My car is stock BTW.

Okay so does this tell anyone anything? This is a freeze frame of when the symptoms occurred. Not the first grey line, but the second green one where the misfires occur. Looks like misfires and kr at gear shift... Does that mean engine, tranny or both?

Will tranny slips set off the knock sensors?