Glad it's running properly now.

Maybe the vacuum line for the actuator was pinched? Or is cracking and leaking?

 

Thanks. I inspected the exposed lines and connector pretty closely, they looked ok. If the issue comes back i will remove the engine cover and inspect them fully.

 

So the issue is back again.. I tried disconnecting connector to the selenoid that opens the secondary flap. This essentially leaves the flap open all the time, not just above 3400 rpm. Even with the connector disconnected the high end growl is significantly reduced (as is power). It is completely random, sometimes it growls other times it does not.

Can the vvti be the culprit? Still no CEL..

 

I know with Vtec it has to do with oil pressure. Not sure about vvti but id take it to the dealer you did at and have them go over every step he did including new oil.

 

Def going back to dealer..they are "researching" the issue.

 

Sorry to see this fella.

Hope you get it fixed soon.

I know these are very sensitive cars though. When I was doing an Apexi throttle controller install for another forum member over here, I accidentally plugged one of the connections in the wrong way round (in fairness, there are no markings I could see, so was a 50/50 gamble). Car through a CEL, other warning lights, went into limp mode etc. I was freaked! Changed the connection around and still not right. Decided to disconnect the battery and reset everything. Worked perfectly after that.

Appreciate you've tried this with limited success. Just hope it's nothing too serious for you mate.

Best of luck!

 

No response from the dealer, i followed up today.

Since the F is my weekend ride i had not had a chance to drive it until today. Once again it lost it''s grunt on the high end. I tried adding NOS octane booster (claims to add 3 octane points) and i filled up with fresh 93 octane. A few WOT runs later, power is back to normal..could bad gas cause such a dramtic loss in performance?

 

Issue is back again..i guess I ruled out the fuel. It was great for about 40 miles yesterday. Then suddenly down on power again this AM before going back to normal again.

 

..............sounds like your MAF sensor is dirty or getting air turbulence. Try cleaning it, reset the ECU again. Check for any loose clamps before the MAF....that may be causing an unbalanced mixture.

This is an easy thing for you to rule out, and dealers never provide this check, without throwing parts at the problem.

Digger08

 

Thanks..will do that next. Gotta go get maf cleaner..

Visual inspection showed nothing..everything is attached correctly.

 

Everything was fine until an oil and filter change? What is keeping you from having them drop the oil, and put in the right stuff? VVTi on the exhaust side is controlled by oil pressure. If they didn't put the right oil in it, it won't work right and the car will run like crap. A good friend had a GS430 with exactly the experience you have, and it turned out to be the oil causing the issue. Oddly enough, he ran Mobil 1 and had problems for more than a year. He put in the Toyota oil they sell in the parts department, and the mystery power loss issues disappeared.

Drain the oil. Put something different in it. Test. Bet it's fixed.

 

Hope it will get fixed soon my friend.

 

Thanks for the advice. Just reviewed the invoice and they put in 5w 30 snythetic..my previous change was conventianal oil. Perhaps i will ask them to revert back to conventional.

 

I said something similar to this from the get go. Hopefully it fixes the ops problems and he can continue enjoying his F.

 

^ thanks.

I removed all the covers and disassembled the airbox and checked the MAF - it was very clean. I sprayed some cleaner on it anyway.

Everything looked fine - the oil will be the next step. Even though the weight it right, my car may not like synthetic.