1J Codes 31, 34, 52

[honestabe]

My 1J is acting up. For the most part it will drive perfectly fine. Then after I launch sometimes it will stutter and not have full power. I have solid motor mounts, so I'm not sure what to do. The codes I threw are

31: Air flow meter signal
34: Turbocharger pressure
52: Knock sensor Signal

Anybody have any clues as to what is going on?

Adam

 

[lewis15498]

Do you have an aftermarketboost gauge? if so watch what it does. my guess is your overboosting. it overboosts tripping the turbo pressure signal. also because its boosting so much, its sucking in more air than your MAF can measure. causing maf signal. also because this extra air isnt acounted for, you dont get the fuel to match and you run really lean. the lean condition is causing your engine to knock. causing knock sensor signal. the engine computer then retards the engine timing which sacrifices power but doesnt help you cuz your engine is still running lean.

check the hose from the turbo compressor to the wastegate actuator. make sure its connected and isnt kinked. also if your using an aftermarket boost controller make sure it isnt turned up to high, and is functioning properly. also make sure your wastegate and actuator are functioning properly.

Assuming you are overboosting do not drive the car until you solve the problem. overboosting can cause severe engine damage.

 

[honestabe]

1J's don't have MAF's, they have MAP's. I'm running an AEM TRU Boost gauge/controller (couple months old). I also have a PLX M-300 wideband so I know at all times what my A/F ratio is. As far as I know I am not overboosting. Last I recall my boost pressure is the same it always is, maxing out around 13.1 PSi. I'm thinking I have a loose knock sensor. My Supra is parked in the garage until I know what is wrong.

 

[lewis15498]

I'm not sure on that, im not overly familiar with 1jz's however your engine have some type of airflow meter if not a MAF otherwise you wouldnt have an airflow meter code. My guess is whatever type of airflow meter you are using is maxing out.

 

[lewis15498]

Generally speaking those 3 codes together would suggest a high boost lean situation.

 

[10secdream]

Try tapping your boost gauge into a different vacuum source just to make sure it is reading correctly. I too would have to agree that it sounds like your overboosting and thus the map sensor is out of range.

 

[honestabe]

I'm running a 2JZ-GTE MAP. I'll do what I can. Wish me luck.

 

[sai_supra1jz]

Good luck

 

[bloodasp90]

adam, you always need luck..

 

[aphxero]

I have spare knock sensors if you need one. $10./

 

[honestabe]

Thanks bro, I'll let you know.

 

[SupraKingz]

In a similar situation what would it mean if its only the code 31 but engine still runs but when stepping on gas pedal quickly it hesitates a lot and will only go higher rpms if you slowly step on gas pedal. Clearly its running rich as hell but what should i be checking out because i know that the 1j doesn't have maf and don't think it'd be my MAP sensors because even when i unplug both and run it without them nothing changes and there is no way that both stopped working at same time.

 

[honestabe]

Check your air temperature sensor. It's located on the intake manifold next to the throttle cable mount and PCV valve. IIRC it's green. It's common for those wires to break or the sensor to get clogged up. You can take it off and clean it off with non-chlorinated carb cleaner and a gentle wire brushing.

 

[SupraKingz]

Which one of these would be the air temp sensor and if it isn't any of these let me know which is it closest too. And thanks for the help because i've had this issue for about 2 months and posted many times about this issue and that was the only helpful info i've gotten even if it ends up not working.

 

[honestabe]

The red arrow. You need a 19mm wrench to take it off. The only way you can get a new one is if you find someone parting out a 1J. I've luckily found mine in Kentucky, should be here mid next week. Here's a better pic.

http://www.supramania.com/forums/sho...43&postcount=1

 

[SupraKingz]

Pic didn't work but that pic is of my engine so i know where the stuff is i'll let you know how it goes with cleaning the sensor. thanks again

 

[honestabe]

Odd. Ah well. No problem bro, hope all goes well. Hopefully you won't have to buy another sensor because you will have to hunt one down like I did.

Adam

 

[SupraKingz]

Well now i'm totally confused because i removed that sensor cleaned it up all nice like you said and put it back it removed main fuse to reset codes put it back and started it and now its giving me the codes 13, 24 and 31 but it runs good now?? like no hesitation in throttle response like it was doing before. So where do i go from here because its running good but still flashing codes.??:icon_evil

 

[SupraKingz]

ok well i disconnected battery and main fuse to totally reset ecu and put evrything back together and now were back at scratch one with code 31 but now it has really low idle at around 500 when usually it was at 750.

 

[SupraKingz]

Man this is messed up lol because after letting it run for a while it runs back at normal of 750 rpm and its fully responsive like it should be when running normal but its still giving me code 31 could it be that my map sensor is screwed and working when it wants to or could maybe a vaccum leak somewhere be effecting the map that much. I'll be picking up a silicone vacuum line kit to replace all vacuum lines it'd be nice if that resolved it.