larryp2023

Hey what’s up

I recently purchased a 2011 Lexus ISF, 75,000 miles. Love the car, drove fine until recently it feels like the power is cut. Like a limp mode
Basically before I could pedal to the metal and the car would go thru it’s gears nicely and shifted quick.
now it feels like when I punch the car, once it hits 5000 rpm’s it goes up so slowly and the engine kind of mutes itself. The car still drives but it’s a very weak acceleration. I don’t have a check engine light, no codes pop up. I clean my maf , I got a new intake. I cleaned my throttle body and I reset the ecu. Still have the same problem
has anyone had this, or does anyone maybe know what else I could check ?

Marcin

It's bad fuel. I've had it happen few times, always after I had to get fuel from some no name station in a middle of nowhere. Burn it off, get new fuel, and things go back to normal.

PrimeDave

Yup...Like Marcin said. Its bad gas.... You gonna have to burn it off (I would not add any additives) probably sooner than later just so I could refill it sooner with much better gas.... I highly recommend you try a different gas station then the one you filled up at. I have great luck with BP or Shell.

larryp2023

I thought so too, I filled up at Safeway with premium and I think I noticed the issue after that.
But then ever since then I’ve only been filling up at shell and the ISF currently has shell premium.
Any guesses on what else it could be? Maybe injectors or fuel pump?

PrimeDave

Idk the maintenance status of your ISF in terms of injectors or fuel pump etc, but I would generally steer away from any and ALL Grocery or Store Chain "gas stations". That said, it is possible that a Shell station had "bad gas" regardless of Octane number. That did happen to me once and it was also Shell and it only happened once about 9 years ago in my X5. I continued to use Shell after that with no bad gas incident again. I've never had bad gas with BP though, ever... And now if possible I specifically look for BP when filling for gas.

larryp2023

Could it be the shell gas station? I mean I filled my car up at the same shell gas station maybe 3 or 4 times and I’m still noticing the same issue with the car when I’m “WOT”. Should I try another shell gas station ?

SoulFreak

iTrader: (1)

Several years ago when I had my 2011. I installed aftermarket spark plugs. It would rev up slowly. Once it got to redline, it will go into limp mode and throw a code. I switched over to oem spark plugs and the issue went away.

larryp2023

would your Lexus go to 5,000 rpm’s and slowly go up or would it in general accelerate slowly from nothing ?

also one of my mechanics said maybe it’s clogged cats, should I take ‘em off see what happens?

SoulFreak

iTrader: (1)

If I recall correctly, I was in manual mode. From a complete stop I would shift from 1st into 2nd & would immediately notice the rpm’s hanging in there longer than usual. Once I shifted into 3rd redlining it. The car would jolt a bit & it would go into limp mode. Starting me out in 2nd gear. I would disconnect battery & reset. It kept doing it, unless I drove normally. The Valley plate was recently resealed & spark plugs. I took back to the mechanic & switched to OEM plugs. I can’t remember the plug model but it was NGK plugs. I didn’t have issues after.

larryp2023

That’s kind of exactly how my car feels like. 1st gear, 2nd gear feel normal until I shift to 3rd it will bring my rpm’s up slowly. Earlier it did it in every gear.
I’ll switch out my plugs then too, and while I’m at it my injectors. I’ll keep ya updated !! Thank you

PrimeDave

I'd DEFINITELY stop getting gas at this same Shell station. I would actively look for a BP station and fill up immediately when able and also look into switching out your plugs.

lobuxracer

iTrader: (2)

Injectors? Maybe you missed the fact there are 16 and 8 of them are DI. Swapping them out isn't called for at all.

larryp2023

Filled up at a new shell gas station, I poured in the fuel system cleaner from chevron. Still the same thing. I think might be my spark plugs? Do I go with OEM or with NGK. O’Reilly sells them for $30 a piece so $240 for a full set. Do I go with it?

larryp2023

So swapping them out might not be worth it yeah? Interesting, last two things I got in mind are bad old spark plugs or clogged catalytic converters

lobuxracer

iTrader: (2)

The DI injectors are $256.79 each from Rockauto. About $290 each from discount Lexus parts sources on the 'Net. So, a couple of grand just for the DI units, we haven't even touched the port injectors yet. You'd be way ahead to buy a can of BG44K and run that through your injectors first.