I've put 700 miles on new headgasket, great power and acceleration till 5000 rpm then limiter action.. power, no power, power no power. The cats are clear. No codes no history. Acts like 2zz-ge when cold..
Is this an aftermarket head gasket that reduces or increases compression by any chance?
Are you sure the head gasket was installed facing the correct direction? It's possible that the head gasket could be in the wrong way and is blocking some coolant journals in the head/block interface.
Any other symptoms? Strange that it's not throwing any codes...
No other symptoms. .. runs really really smooth. Feel very confident in head gasket install. Airbag light blinking though. Any chance that's a connection?
There's a recal on the passenger airbag deployment system, it's likely faulting and that is what is giving you the flashing seatbelt light.
But that wouldn't limit your power... I'm leaning towards triz's diagnosis of a clogged cat. Or any form of obstruction in the breathing system. Are you certain that all electrical connections were made when reinstaling the head? Maybe try doing a hard reset on the ECU. Just unplug the battery and let the capacitance drain from the ECU.
You're pretty much stuck until it throws a code or if someone else has had this issue.
I figured soo. Was told maf could cause strange performance. But already cleaned it, no change. I owned a gt new ten years ago... loved it.... but when it was cold it would "limit" the engine at what I think was the same 5000 rpm until warmed up...just wondering if the ecm isn't getting the right sensor signals and thinks its not ready.
Does the dash display the correct running temperature? The needle should be just touching the little temperature symbol on the gauge for VVTLi to initiate.
Check the coolant temperature sensor and all wires leading too and from it.
Actually... Did you remove the VVL solenoids from the head when you did the work on it? This could be an issue with the VVL solenoids. If they were swapped from side to side or installed incorrectly it would prevent VVTLi from engaging. Check the connection on the solenoids on the right and left side of the head. Also, check the oil pressure sensor above the oil filter. I've had issues where those break quite easily.
I'm having the same issue. I really could not of wrote it any better. Did you find the problem? Maybe I have your old car lol. 03 gt dark blue in Michigan