P0335 Crank Position Sensor A Circuit Malfunction

[dougefresh_]

I haven't thrown my CKP sensor code in over a couple hundred miles. I think everything is fine with my car. It pulls great, no kr over 1, 26psi, no blow out, and afrs almost dead on 12.0. I'm going E30 on the first fill up after I get the scalars for the eth.

[dougefresh_]

^Everything's not fine, lol. I bent a rod a couple weeks back, and threw this code earlier that day. It may have nothing to do with it, but it still bothers me. I talked to the dealer about it, and there's a flowchart diagnostic for the CKP sensor that they use to diagnose P0335, and I asked him to email me a copy of it. As soon as I get it, I'll post it in here.

[SSinstaller]

[dougefresh_]

Well my car is up and running, but I'm throwing this damn code again, but now every mile. The car runs fine... there may be some metal bits in my oil after honing or from the piston scraping the cylinder wall after it bent. I'm just going to deal with it for now, and then after I change my oil at 500 miles, see if it improves any. If it's just as bad, I may bring it to the dealer and have them fix it under warranty.

I just hate having a cel light up, in case another pops up, I'd have no idea. So that kinda sucks, especially considering we tore down the motor and reassembled everything this weekend, lol.

[Ziggo]

I just started throwing this code after installing the JBR 3.5" intake. I have no other symptoms. I relocated the ECU so I'll run thru the multimeter checks, but my suspicion is this is a grounding issue, that something is spoofing the MAF to spike enough voltage to read 2g/s after which the ECU looks for the CKP sensor and doesn't see it and throws the code.

[Ziggo]

I verified all the electrical connections last night. I don't have a milli-ohm meter or a scope so I can't evaluate the quality of the ground, but I realized I don't really have to since I can directly log MAF voltage.

So what I did this morning was log the MAF voltage with the key on, engine off and engine cold at hot idle and with the key on engine off at hot.

I can't look at the logs till this evening as my laptop is currently dead, but the live data showed both KOEO measurements at .7-.8V and the warm idle (950 rpm) a/c off @ 1V

What does this mean? It means that all cells of the MAFCAL up to ~.9V should be zero. I will look at my tune tonight, but I believe I have a couple cells in the .7-.9V range that are greater than 2g/s, which means that the ECU is expecting to see the CKP sensor responding before the engine is started.

The larger the MAF, and the higher % of scaling done for e85 will make this problem more apparent.

Note: all MAFs should baseline at the same voltage, but your idle voltage will vary based on the MAF size. If your MAF gets so large that the idle voltage is on top of the base voltage, you are going to have to raise the idle till it gets above the base voltage.





Zigatapatalka

[atvfreek]

@dougefresh_ I think ziggo has this figured out. It makes perfect sense. Especially since you are running a 4" intake and have scaled your maf even further for the intake leak you have. This is an easy adjustment to try.

[atvfreek]

@Ziggo here is a scaled maf curve for the JBR. Good call man. This is from .31-.9v... With a normally scaled maf, the .35v is only .2 or so.

0.00	0.04	0.05	0.11	0.16	0.25	0.34	0.48	0.59	0.76	0.91	1.10	1.32	1.55	1.80	2.06

[Ziggo]

I am scaled up another 22.5% to compensate for my e85 mix as well.


Zigatapatalka

[crazyp]

I havent had this code pop up in months now. Would cooler air make the maf fluctuate also? Thats when I use to the the code once a week, when it was cooler or very humid out

[Ziggo]

Originally Posted by crazyp I havent had this code pop up in months now. Would cooler air make the maf fluctuate also? Thats when I use to the the code once a week, when it was cooler or very humid out

The baseline MAF voltage will move up in denser, colder air, so yes.

The MAF sensor just detects how much cooling a resistor is getting. Denser, cooler air will cool the resistor more even with the car off.

Will have to revisit this when it's cold out and see how much of a difference it makes. It's why I took KOEO measurements with the car cold and hot, but I don't know if there will be enough variance in temperature to show the effect.


Zigatapatalka

[Ziggo]

Attached are a few logs. With the baseline maf voltage at .67 it shouldn't cause the MAF to report >2g/s but I am going to give the following edit a try anyway.

[Ziggo]

2 days, 6 key cycles, and no CELs thrown yet. Before it was happening every other key cycle or so. Since I am not a post whore I won't keep posting updates unless it happens again, so assume the fix works unless you hear otherwise.

[Zbrit00x]

Just threw p0335 and p0245, I'm in same intake. I'm going to try this

[dougefresh_]

I zeroed out my maf a/b from 0-.9v, and haven't thrown this cunt code since (~200 miles). Thanks again @Ziggo!

[Tokay444]

And brown.

[dougefresh_]

Originally Posted by Tokay444 And brown.

Take it easy, eh? I'm saving up my loonies and toonies.

[Tokay444]

I know all's aboot that.

[Voltwings]

Ok, gonna have to dig this thread up because my car is having some serious problems.

Went to the track Friday night to just get some 4th gear datalogs in, did about 4 pulls that night, and last pull of the night the car just went haywire. Basically, I made it through the run ok, but in the return lane my AFR's went into the 8's - 9's and the car cant make it over 5 mph without spitting and sputtering. I reflashed another map, but it didn't help.

Towed the car home and started trying a few different things:
1. Fuel pressure was dropping with a warm car, engine off, so I figured the rail valve was busted. Swapped it, nothing.

2. Figured maybe an injector was stuck since the fuel pressure was dropping, and I already swapped rail valves and the pressure can only leave the rail one of two places. Checked spark plugs and they're all fouled.

3. Got a datalog and realized car is idling at 1.5v - 1.9v which explains my stupid rich condition, and car threw the po335 (CKP circuit whatever) code.

4. replaced MAF and flashed another map in for shits and giggles and the AFR's were stable and MAF volts were 1.1 just like they were supposed to be, fucking sweet! Touch the gas pedal and the car bucks, sputters and we're right back to a 9.1 AFR -_-

5. Figured maybe throttle clip was busted, because the car was very sluggish to react to throttle input (likely due to stupid Rich AFR's) but after swapping throttle bodies (im sure you've noticed all my friends drive mazdas by now) its still doing the same shit.

Basically the only thing I can think to do is pull the CKP and clean it but I have no idea where it is, or where to even start looking if that doesn't fix anything. Basically I know the MAF is the culprit ... I just don't know why, so any help would be greatly appreciated. Thanks.

[atvfreek]

Originally Posted by Voltwings Ok, gonna have to dig this thread up because my car is having some serious problems. Went to the track Friday night to just get some 4th gear datalogs in, did about 4 pulls that night, and last pull of the night the car just went haywire. Basically, I made it through the run ok, but in the return lane my AFR's went into the 8's - 9's and the car cant make it over 5 mph without spitting and sputtering. I reflashed another map, but it didn't help. Towed the car home and started trying a few different things: 1. Fuel pressure was dropping with a warm car, engine off, so I figured the rail valve was busted. Swapped it, nothing. 2. Figured maybe an injector was stuck since the fuel pressure was dropping, and I already swapped rail valves and the pressure can only leave the rail one of two places. Checked spark plugs and they're all fouled. 3. Got a datalog and realized car is idling at 1.5v - 1.9v which explains my stupid rich condition, and car threw the po335 (CKP circuit whatever) code. 4. replaced MAF and flashed another map in for shits and giggles and the AFR's were stable and MAF volts were 1.1 just like they were supposed to be, fucking sweet! Touch the gas pedal and the car bucks, sputters and we're right back to a 9.1 AFR -_- 5. Figured maybe throttle clip was busted, because the car was very sluggish to react to throttle input (likely due to stupid Rich AFR's) but after swapping throttle bodies (im sure you've noticed all my friends drive mazdas by now) its still doing the same shit. Basically the only thing I can think to do is pull the CKP and clean it but I have no idea where it is, or where to even start looking if that doesn't fix anything. Basically I know the MAF is the culprit ... I just don't know why, so any help would be greatly appreciated. Thanks.

Are you spraying meth still? I have seen leaks spray right at the maf sensor. And caused weird issues.

The ckp is external to the engine and is right at the crank pulley.

[Voltwings]

Originally Posted by atvfreek Are you spraying meth still? I have seen leaks spray right at the maf sensor. And caused weird issues. The ckp is external to the engine and is right at the crank pulley.

No meth, and I rswapped MAF's already to see if that changed anything. The passenger side of the car is against the garage wall so I may check it out tomorrow after work, although I highly doubt just wiping that thing off will fix anything. Its pretty obvious the issue is the MAF lol but again, I don't know why, why would that code cause the MAF voltage to change you know?
@Tokay444; I believe you said ignition should be 10* Stock? In my datalog it was like -1, -2* and the car was idling at .7, .8, almost .9 load. I cant say ive ever logged idle for anything other than MAF cal so I only looked at those regions, do these parameters seem crazy out of whack and point to anything?

[Voltwings]

Sorry, I don't know how to add this Datalog to my previous post.

[Tokay444]

Yeah you should be idling at 9-11* ignition.
What are your trims?
The ckp a magnet, so it's possible it's picked up some shavings.

[mrmonk7663]

Ok, lets go down this road...it slipped timing or the sensor is misaligned because it loosened up, or it has metal shavings stuck to it....to fix this type of issue, you would need the timing tools right? Based on this thread it appears that you cannot simply uninstall the sensor, clean it, as you need to properly align it and air gap it right?

[Voltwings]

Originally Posted by Tokay444 Yeah you should be idling at 9-11* ignition. What are your trims? The ckp a magnet, so it's possible it's picked up some shavings.

Trims are useless haha, pegged at -25% since im running so rich. I figured it may have picked some shavings up, but theres over 5k miles on this built motor, and I was very good about the oil changes, surely it would have happened before now?

Its been suggested my car jumped timing, as my logged values do not reflect my commanded values, however, in my mind if you mechanically skip 1* you should always be off by 1* right? Not so in my case if that's what actually happened, compare my logged vs commanded for idle and free revving.

Idle (note, idle load is higher than free revving??)


Free rev

[mrmonk7663]

Here is the information in the factory manual concerning removing the sensor, installing a new one, and inspecting the sensor.

[Tokay444]

Look into primary o2, though it doesn't entirely explain the p0335.

[Ziggo]

MAF voltage is reading too high. It explains all the other problems so until you sort that out don't go bothering anything else.

Zigatapatalka

[djuosnteisn]

Idle spark advance won't be on target unless the car is idling smoothly. If your MAF is all haywire, and AFRs are in the 9's... the spark advance is pretty much worthless.

My guess is a grounding issue probably. Or a weak battery or something. Crazy things happen when the battery is near dead.

[x09MS3GT]

Originally Posted by Voltwings Sorry, I don't know how to add this Datalog to my previous post.

Dude, im not gonna lie here, and I could be very well wrong, however. I just looked at your log and this is the same EXACT fucking BULLSHIT i just went though about 2 months ago.

I had never tossed a code or had a single damn problem with my car.
I drove it to work, typical day, car sat in the lot all day. I get out to my car 9 hours later, start it, and for no goddamn reason , my AFRs are stuck at 8.XX , STFT pegged at -25, and the car is trying its hardest not to drown itself in gas and stall. I didnt let it sit around long enough to throw any codes however. Car was bucking like a fuckin bronco....

I got home, RE-flashed my tune, and the problem seemed to go away. But it came back about a day later. Only thing i could think of was that maybe i had gotten a batch of leaded 110 instead of 104 ( i mix race gas, its my solution to alaskan pump 90), and that maybe my 02 sensor had had enough, so i bought another one through rock auto for 101 bucks shipped.

Problem free since. Trims are normal as can be, however, i do notice that sometimes by STFT will go from a high negative value, then jump completely opposite to the same value, only positive. It does it every so often, but AFRs are spot on, and the car runs normally.

I dont know what caused it to be honest, but your log is IDENTICAL to mine. Same timing, same AFR's, everything. It cant be coincedental...

* edit, i did pull the MAF and clean the shit out of that thing as well.
*And my Densos were pretty much fried as well.

[Tokay444]

Check wiring harness isn't rubbing on tip/intake clamp.

[mrmonk7663]

His O2 sensor wiring harness rubs up against the EWG...he has a piece of heat wrap on it...think that over time the heat got to the wires and messed them up or shorted out the sensor?

[rigor]

purge valve messing up causes super rich at idle i just pulled mine off sprayed some light lube in it, and that was 40000 miles ago ,still working great

ill post a vid in a minute

[rigor]

Rich idle purge valve fix - YouTube

good luck

[dougefresh_]

Originally Posted by rigor Rich idle purge valve fix - YouTube good luck

So glad to see you finally hosting vids on YouTube, instead of failbucket!

As a minor update, I've never thrown P0335 since doing the maf adjustment that @Ziggo; suggested a ways back.

[rigor]

ya that definitely sets the crank code for some reason

and while the purge valve is out, give it a good suck / blow to attempt to free it, or tap it on one end than the other....

[Voltwings]

Originally Posted by rigor Rich idle purge valve fix - YouTube good luck

lol i'll spray some shit in both ends of mine after work tomorrow and see whats up thanks.

[Voltwings]

Good news, cleaning the purge valve seems to have corrected the idle, back to 1.1 volts as it should be, bad news is any throttle input at all bogs the car so I am now going to attempt cleaning the CKP.

[Tokay444]

Primary o2.

[maisonvi]

Subbed to read later because I'm throw this too

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