BlackS2

Ive had a 2010 MT since January with no big issues. Its completely stock except for a Agency Powered catless midpipe and catback exhaust (Before i got that I gutted the cat so the sensor is toast) It only has approx. 53k miles, I stay on top of oil changes, premix, redline a lot, and never drive before it is warm. However, lately it has been taking longer to start and in the mornings before it warms up it has a bit of a rough idle (sort of sputtering/shaking). Anyways, the other day when i hit about 5500 rpm it had a bad misfire and stalled out on me (never had a misfire or stalled randomly before). I managed to crawl it into a parking lot where I attempted to start it again, but to no avail. I checked the codes and besides the misfire, I had P0113 (Intake Air Temperature Circuit High Input), P0171 (Lean Air/Fuel Ratio Bank 1), and P2270 (H02S12 Signal Stuck Lean). I looked those up and people were still driving with them, so I replaced the ignition coils, spark plugs, and wires so that i could at least get it home before fixing the other problems. However, after i replaced those it still would not start. It cranks and sounds like it is about to turn over but never does. Any ideas as to why it won't turn on? Could it be any of the things its throwing codes for or is it a bigger problem than that?

Loki

iTrader: (1)

The IAT code points to you MAF not being connected, ir being destroyed. The IAT is in the MAF.

Is there oil in your intake? The other 2 might be from your midpipe, but might also be further electrical Gremlins. Do the codes return if you clear them? The O2 signal isn't used for starting anyway, so worry about those once it's running again.

Have you tried the deflood procedure? How quickly (rpm) is your starter turning the engine during start attempts?

BlackS2

the MAF is connected but I guess it’s broken if that’s what that means.. I’ll try cleaning it and seeing if it goes away. There is no oil in the intake and I will clear them tomorrow to see if they come back or not. I havent tried the deflooding procedure yet, I was thinking that it might be flooded but a buddy of mine that knows more than I do told me that it’s extremely hard for the S2’s to get flooded and he didn’t think that was the problem, but I will also try that tomorrow. I’m not sure about the exact rpm as I wasn’t paying specific attention to it, all I know is it was around 1k. I’ll let you know tomorrow.

mazdaverx7

iTrader: (6)

Inspect, test, and clean the maf. That's what I would do first. How did the spark plugs look when you removed them initially? Were they soaked in gas? How do they look now? Can you hear the fuel pump priming when you turn the key to the on position?

CaymanRotary

Absolutely they can flood. Always try to deflood if having starting issues especially since you changed out your whole ignition system. Your car should start because misfires and loss of power usually related to ignition system which you’ve already solved. Only other thing it could be is catastrophic loss of compression related to seal damage. Wouldn’t hurt to compression test if it’s still giving you issues or if deflooding doesn’t work.

Loki

iTrader: (1)

You'll need an OBD reader to get exact rpm. Starter rpm ia between 200 and 300. The slower, the harder it is to start.

Check/clean/tighten battery posts and clamps. Poor battery connection can cause stuff like this.

BlackS2

I’m trying to deflood it right now, but every time I start cranking it has a single extremely loud backfire, literal gunshot levels. It’s just a single one right after I start cranking, and I’m concerned but have no idea what could be causing it. Anyone have any ideas as to what it might be??

Loki

iTrader: (1)

Are you holding down the gas pedal while cranking? Backfires = fuel in the exhaust, so either it needs to clear out through further cranking, or you might have connected the spark plugs to the coils in the wrong order.

BlackS2

Turns out I hadn't disconnected the fuel pump the right way, and I couldn't just hold the gas pedal down, since that doesn't work on the 2nd generation. It stopped after I disconnected it, but after it had unflooded I turned it on just for it to sound the same as it did when it had the bad coils in it. The CEL wasnt flashing, so it wasnt misfiring, but it was still backfiring a lot and sounded like a lawnmower. I checked the air filter and saw a black spot on it, so I came to the conclusion that the original misfire went through the intake, and destroyed the MAF sensor. My buddy let me use his MAF sensor (he has a 2004), and it no longer sounded like a lawnmower but it was still backfiring every couple of seconds, and I still had to keep the car alive by pressing the gas pedal. It also threw the P2101 (Throttle Control Motor) code, and at this point I am at a loss as to what could be wrong. I made sure the spark plugs were connected to the coils in the right order. Could the fuel pump be messed up? I noticed when i would fill up the fuel gauge wouldn't go all the way up, but would behave normally other than not going all the way up. i didnt think anything of it I just thought the fuel gauge sender was messed up, but the night before the original misfire, I got in my car just to notice I was on the very last tick with the fuel light on, but I am certain that it was not that low when I had last drove it. I made it to the gas station a mile down the road, and after filling up it made a weird gurgling sound. I'm not sure if that has any correlation to this, but figured i should let you guys know just in case im missing something. Any ideas as to what could be wrong other than the MAF sensor? Whats causing the code and the backfires and the extremely rough idling? Compression is constant and its not just firing off 1 rotor.

Loki

iTrader: (1)

That's not how misfires really work. It couldn't have gone through the intake, no single rotor face can have both the intake port and the spark plug open to it.

The throttle motor code and all these other random codes sound to me more like an electrical issue. Starting with loose/dirty battery terminals or loose/dirty grounds. That's the one thing all of the affected components have in common.

BlackS2

what do you suggest I do to fix it? I made sure the terminals were clean today but what else can I do?

Loki

iTrader: (1)

I'd start by making sure all the connectors to the ECU are clean and snug, testing the battery voltage while the car is running and checking every grounding point you can find., especially near the ECU.

Those steps should detect or eliminate poor grounds or system voltage being too high from a bad alternator voltage reg. After that we're into tracing the wires of each electrical components which repeatedly triggers this code, which is less fun. Or, replacing those components, but the odds they would all fail at once are poor.

Still a bit curious about the dark mark in your filter. I didn't think about it before but if it's really a burn mark, perhaps you did have a backfire go through the intake. It's possible but very unlikely since our engines don't have overlap.

... unless you've lost a seal and now have overlap..

BlackS2

if I had lost a seal and had overlap wouldn’t the compression not be constant? I’m just taking a guess here but when cranking it is clear that the compression is constant

Loki

iTrader: (1)

If 2 or more seals are gone, compression will still be constant and constantly poor. But, I'm not suggesting that's what you have, if the electrical investigation doesn't lead any where, we can revisit the nature of that mark.