Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB

Quote:

Originally Posted by Frs300 (Post 2356907)

So heres the deal i have built motor and p&l turbo kit.

I can start the car and let it run until its up to temp and my idle afr will be at 14.7. I go to drive off and the car will hesitate for a second then it will want to haul ass. The car will drive fine for about 15 min or so then it just takes a dump. Car starts to die at red lights. Rpms will shoot up to 1300 them drop down to 300 and afr will also start to swing from 14.7 down to 11 then up to 17. Which makes it damn near impossible to get going from a stop. When cruising at 3300 rpms 45mph or ao the afr swings and you can hear the exhaust sound change. When afr swings while driving rpms never change. Crusing down the highway at 60mph+ car drives fine and afr is 14.7 all the time.

I have changed out the maf, map, fuel pump, used oem pump, fic injectors as well as o injectors, new di controller, checked for vacc leaks and found a few small ones as well as fixed leaky injector seals and the issues didnt get any better. Im at a loss on wtf it could be short of something internal.

Sounds like you have an issue similar to one I had / may still experience.

I am running an HKS V2 Supercharger and ECUtek Racerom. My car ran good however I kept getting these phantom P2096 and P0171 DTC's despite my AFR's being good (confirmed by reading from both the stock O2 sensor datalogs and my AEM Wideband)

About a month ago I was just cruising in 4th and suddenly the engine bogged down hard - CEL started flashing and I had an immediate loss of power and throttle response.

I pulled over and the car was misfiring severely and eventually refused to idle. P0300 and P0304 DTC's came up and were consistently thrown even when I cleared them and tried to get the car to idle again.

Because this translated as a consistent misfire on the same cylinder I examined the coilpack, spark splug and also checked the MAF. Everything checked out and no other codes were present.

After a lot of hopeless searching I stumbled across the TSB for cam position sensor issues and the 2 codes I had as well as my conditions matched the bulletin enough to investigate it.

The dealership here found I had a cam position sensor out of spec and after they shimmed it the car started and idled again.

The car also seemed to struggle at first to re-learn - however some odds and ends in my tune (non AFR / fuel related) may have contributed as well as a light flywheel + crank pulley.

I got the car back and reflashed it with a Flash and Go tune from @DeliciousTuning. The car started up and immediately idled, did some quick searching and then sat at 14.5 without even a twitch. Cruising was smooth - AFR was on point and all seemed well.

Then something weird happened .. I was just cruising around again and all of the sudden I felt that similar loss of power and throttle deadness. The AFR started swinging around the the car seemed to be misfiring / trying to stall. I did a thing I shouldn't do ... I got a little angry and started giving it some throttle / revving up.. and lo and behold I smell some sort of faint burning like something just made it's way through the system. I eased off and then ... ... it smartened right up.

I took the car back out and cruised around without issues. So I did a couple 1-3 pulls to datalog some info for Delicious to see how the map was. I looked over the logs myself before sending them off and everything looked pretty good. Like ... surprisingly good for what is an OTS tune. I haven't had a single hiccup since.

I've been driving the car around - doing pulls - stabbing the throttle.... everything is behaving super well.

Knock on wood.

I don't know how helpful my experience is for you due to my unorthodox "rev the piss out of it in anger" when it was bogging a bit -- but the main take-away is I did have a cam sensor out of spec and after it was replaced the car was drive-able again whereas before it would not even idle