WingleBeast

Here is the rundown:

I had been gone for 62 days and have not driven my car in this time period, during my absence my car had to be moved, and you guessed it, they flooded it. A car flooded for 60 days is hard to get started but I managed to do it without changing the plugs just by removing the fuel fuse method. Judging by the amount of fuel in the housing, they had tried to get it started by cranking a lot. I drove the car around town for a day (less than 50 miles) then today I drove to Atlanta (120 miles) without a problem.

Driving home from Atlanta, I noticed at around 80mph if I try to accelerate my car would give a small jerk and actually decelerate, as if I misfired in a piston engine (I am using this as reference since I have never misfired in a rotary but am very familiar with piston misfires) So while I am driving I try and troubleshoot this with my AP and all numbers seem normal. And finally after about 30 miles it gets to the point where any heavy load in any gear just makes me jerk around like crazy. However if I just gently apply throttle, I can accelerate and drive normally, likewise; the event is not always repeatable at the same load or RPM. The car will also turn off and startup normally, but still has an all around loss of power.

This leads me to believe the following:

1) not a sealing or compression issue, since that would produce a repeatable lack of power, and be more prevalent at low RPM than high. there was also no pop or suddenness to the problem.
2) good battery and alternator since I read a constant 14V with the AP during the "event"
3) not a sensor failure as there are no thrown codes

So based off research and assumption it seems that I am looking at a melted cat/coils issue. perhaps the fuel I had to dump out of the engine during unflooding ruined the cat when it was heated during the long drive to Atlanta. Or my coils were fried while trying to crank the engine for 30 min

or am I completely wrong and this is a bad fuel pump? or another issue I haven't even though of? Any help would be appreciated.

WingleBeast

im really not sure on the AFR numbers, they will bounce all over the place from upwards of 23 to 10, but i never get a knock or ping not sure if those readings are just from the misfire, im not sure how unburnt gasoline affects a wideband sensor reading. however under full load right before the car starts jerking i will read a good 11.5 or so like It should under load.

with the factory flash I am getting a code for the rear O2 sensor, melted cat? The explains the power loss but the misfire and jerking around? seems like a bit much for a clogged cat.

Flashwing

Sounds similar to the fuel pump issues I had and if so it's pretty easy to tell the problem with the AP. I was able to nurse the car along by keeping the throttle application light so the pump didn't kick into high output.

If you're seeing very lean air/fuel readings and also near +25% short term fuel trims while it is happening I would suspect a fuel pump. If you're seeing rich conditions, excessive negative fuel trim or very little change at all then it's clearly not fuel pump related.

Your air/fuel ratio will peg the sensor at 21:1 or higher when you are off-throttle in gear. This is because the injectors shut off during this time. Otherwise, you shouldn't see readings like this during any period where you are on throttle.

Best bet is to take data logs and try to reproduce the issue.

TeamRX8

iTrader: (25)

IN my experience it won't flood period unless you have a compression issue regardless

WingleBeast

when problems arise the number will just bounce back and forth from lean to rich the same way the car bounces around, ill data log tonight and check out the trims.

i put the factory flash on as soon as this started happening so i could pull all the error codes, but i havent driven it much since I am afraid to make this worse.

stock cat.

WingleBeast

well here we go, took it to the dealership for a compression test, lots of data logging, and watching AP numbers while driving.

dealership said compression was good which is a relief.

interesting things:
1) my vacuum is reading low, not sure if this could be back-pressure from the cat, or if I have compression issues.
2) my AFR reads around 14 during the events and will slowly creep down to 12 with the throttle down. seems to get rich too slow though.
3) short term fuel trims are going heavy negative, around -15 to -25 during the events.
4)my throttle position wont open more than about 65% even with the pedal to the floor. is this a symptom or a cause?

tomorrow the cat comes out and the midpipe goes in. I hope this clears up some of the power issue but i'm willing to bet it wont fix the jerkyness events. this still sound like coils?