P2188 and P0302

Year/Make/Model: 2009 Mazda Mazdaspeed 3
Mileage: 196582
Location: Tucson, AZ
DTC's: P2188 and P0302
Modifications: Cobb intake, EGR delete, balance shaft delete. rebuilt engine myself, now has about 10k miles on it. all machine work was NOT done by me. bored out .5mm over, same internals except pistons, same crank, rods
ECU/Tuning Software: none
Tuner: none
Is the concern intermittent? No, it is constant
Can you duplicate the concern? Yes, seems like misfire is really exaggerated under load, like 3k-5k RPM
Recent Repairs: new plugs gapped properly a few thousand miles ago
Correction: none yet



Been reading a bit about it on the forums, could be fuel injector seals? I did the fuel injector rebuild kit when I rebuilt the engine.

Did four new spark plugs a few months ago I wanna say, properly gapped all of them. The ignition coils are a mish-mash...some OEM, some not.

Haven't taken the plugs out quite yet to inspect, and I plan to do a compression test in another couple days when the tool gets here.

Attached is a screenshot from bluedriver about misfire info, as well as CSV of the logs from about a 10 min drive, around the 520 second mark I got into the throttle quite a bit, and the misfire got so bad that the CEL went from solid yellow to flashing yellow, then returned to solid a minute or so later.

Any help is appreciated. I'll be tearing into it later this week or probably next week, just wanted to get an idea so maybe I can order some parts before it's taken apart in the driveway.

Thanks guys!

 

@Raider

any possible help here?

here are some logs, in xlsx and .csv, the excel are a lot prettier and easier to navigate

also here is a picture of the spark plug out of cylinder 2

did a compression test and came back with

cylinder 1 - 168 psi
cylinder 2 - 142 psi (160psi after I put a tablespoon of oil on top of piston) - rings on their way out?
cylinder 3 - 170 psi
cylinder 4 - 165 psi

The last couple days I've been getting a REALLY rough start up, then after about 30 seconds it smooths out at 2k rpm and doesn't cause any problems after idling down

however, under mild acceleration there is some stumbling and misfiring, but just parked and holding it at 2500 rpm or blips up to 4 or 5k rpm im not feeling any misfires.

my feeling right now is...i have an injector on it's way out in cylinder 2. either the injector seals are bad (which i redid during the engine rebuild about 10k miles ago) or the actual injector is bad.

codes are now P0300 and P2188 for what it's worth

anyways, any help is really appreciated. thank you!

 

So constantly lean on bank 1, check hpfp ground it causes.lots.of issues, clean and tight it needs to be.

Mix mash of coil packs probably isn't helping the random misfire OEM is really all you want, tasca has the cheapest that I'm aware of however be aware of long shipping times currently.
https://www.tascaparts.com/oem-parts/mazda-ignition-coil-lf2l18100a

Could very much be injector not being happy / leaking, were the injectors ultrasonic cleaned when you rebuilt the engine? however I'd reccomend a prv test with the engine hot

Hopefully some others chime in

 

~400 psi at the rail during idle isn't bad, but for cruise I think that's low. You probably need to rebuild the HPFP at a minimum. Also your logged parameters need some fine tuning as you have stuff in there you won't ever need while more important stuff is missing.

 

@Awafrican

cool thank you for chiming in. I'll check the HPFP ground first thing when I get home. the injectors were not ultrasonic cleaned when i rebuilt the engine, but i did do all new seals upper and lower, also btw p2188 is for system too rich at idle, not too lean. or were you referring to it being constantly lean from looking at the logs?

@Enki

i did not rebuild the HPFP when i did the full engine rebuild, because I didn't wanna spend the extra cash on upgrading it if I remember correctly....and yeah I just logged a ton of stuff using versatuner. anything specific you might recommend removing/adding?

 

Go ahead and get corksport hpfp internals and replace existing if they have miles. My auto tech froze up. Also they sell the hpfp rebuild kit so all at once.

 

Here's what I log for day to day:
Absolute load
Actual Equivalence air to fuel ratio
Mass airflow sensor voltage
Engine RPM
Boost pressure
Accelerator Pedal Postition
Boost air temp
Wastegate duty cycle
Knock retard
Injector duty cycle
Long term fuel trim
Ignition timing advance
Short term fuel trim
Relative throttle position
Fuel rail pressure

Also, you don't need to spend money to rebuild the HPFP. It's mostly just cleaning.

 

Raids, you don't normally need a rebuild kit unless you have damaged seals (in which case don't install the damn thing improperly and you won't have issues). No, you don't even need it with corn; I'm on full e85 with my OEM orings in the HPFP still.

 

@Enki okay awesome. did you look at the other log labeled "startup and idle w few blips at end"?

you can see there that fuel rail pressure is high immediately after startup until RPM stabilizes around 30 seconds in, and then fuel rail pressure falls until it stabilizes again around 400psi

then, if you look at time = 350s and t = 358s, during two blips, you'll see the fuel rail pressure jump up accordingly. but then during cruise at 2500 or 3000 rpm it's totally stabilized at 400psi

what *should* fuel rail pressure be at cruise around 3000rpm? 85mph?

@Raider will do, im looking at the corksport site now, ill probably pick that rebuild kit up and throw it in.

 

P2188 doesn't even show up in the workshop manual when I google it it says to lean as the first hit, and too lean on the second link.
https://www.yourmechanic.com/articl...the P2188 code means,alter the air-fuel ratio.

https://www.obd-codes.com/p2188

If it's too rich then a simple maf cleaning and checking that harness is certainly in order, o2 sensor could be headed out as well from what I can find on it

 

@Raider weird, this is the screenshot from bluedriver that I pulled the other day. I'll run the codes again from versatuner in just a bit and post those again.

I cleaned the maf and the air filter yesterday and checked the maf harness, everything looks okay,

 

I trust nothing. I mean my car heard me help a customer buy a pivot shaft seal kit and she literally pissed gear oil on my floor.

 

I'm working on getting him to my little neck of this shithole town for discussion and diagnostics.

 

took a new log this morning during the drive to school and logged everything you said to @Enki

also @Raider here is a screenshot of when i pulled codes after I got home the EGR is from the EGR delete I did so that mystery is solved hahaha