Hi Everyone, got a 2010 Lexus IS F and love the car to death.

I have been having this annoying intermittent stalling issue that seems to be completely random. When I’m stopped and idling, the rpm’s will jump and drop with the occasional stall. The car then has difficulties starting back up but on the 3rd or 4th try it will usually work. Won’t happen for weeks in between with no signs or warnings. Seems to happen slightly more often in cooler/rainy weather (could be coincidental). Car doesn’t throw any codes out.

Tried to get Lexus to diagnose with no success as the issue was not happening.

no apparent vacuum leak and spark plugs are fairly new and new battery. Car idles at 700 with AC on and 500 with it off. Looks like previous owner had made some potential modifications, but seems like it’s back in original condition.

any idea out there that could be causing this? Makes for some annoying background stress when I’m driving, especially at a red light lol.


thanks in advance!!!

 

I had this same issue months ago. Your car might not show a CEL but it has likely thrown a code(s). Did Lexus scan for codes? Pull the codes and see what they are. I do not remember what the code numbers were that I had, but the car threw a rough idle code and something else with no dash lights. I reset the codes. A little BG 44K & was all good the codes did not come back. My advice would be to pull codes even though there may be any dash light.

 

Like what Toprawman said above use some BG 44K and run it through the fuel system a couple tanks at least (I know it's not cheap but that's what I would do to ensure the cleaner goes through the entire fuel system a few times). Another thing to check would be the MAF sensor see if it's dirty or just buy a replacement Denso unit to have on hand as a back up if the original MAF ever gives you problems like stuttering or idle issues can be a result of that as well.