First up the Code 34, DET Sensor. I have searched, but i still have some questions... 1. I couldnt find any info on whether it would be safe to bypass the sensor, on an NA Automatic car. Suffice to say the auto trans shouldnt let me lug the engine up hills and NA means i shouldnt be running out of injector duty cycle... So is it something i could leave in? 2. Also, according to the consult interface, i am getting a code 34 for the last 0 starts (i read the code after i had started the engine). Does that mean its only a one-off, or that it is happening ALL the time? The point of all this is that I am experiencing some annoying hesitation issues, and absolutely insane fuel consumption (more than 1/4 tank in 32kms so far!). I turned on the logging function in TECU and i have mapped the results below. Unfortunately it only seemed to capture 34 seconds, so its only idling at this point (with a slight stab at the throttle at one point). But can anyone comment on the results below? What are A/F Alpha and the A/F Alpha Self Learn? A/F Alpha goes to 100% when i am accelerating while driving...
Det sensor bypass is safe if you follow some guide lines Because you have an NA you chances of detonation are slim, even more so cause you have an Auto which you have already identified. I highly recommend a bypass to save your fuel consumption, just make sure you run premium fuel, although 98RON is without question the safest fuel, 95RON will be fine in an NA providing your ECU is stock. Injector duty cycle is more a concern with leaning out and not pre ignition which a det sensor will not avoid anyway. Go to the tech section and have a look at the A-Z index and look at fuel consumption and you may find some more answers there. There are many a Zed running around with det sensors bypassed, as you may already know to replace it requires an engine pull. I gaurantee you when you get rid of code 34, your fuel consumption will decrease greatly.
some answers you ca bypass the det sensor. With some dyno testing, a buggered det sensor knocks off about 10rwkw on an NA (proven at the last melb dyno day). Also, zero starts means its happening all the time so its buggered... As for the safety, well many people say that the NA is safe and wont ping. However, I and some other forum members would disagree with this statement as some NA's (mine included) have been plagued by light throttle pinging at about 2500rpms in the heat. This is not surprising because a) the NA motor is a high comp engine (10:1) and b) at those light throttle applications and at those revs the timing is at about 38-40 degee's (as shown with datascan while driving). Thats very high timing. A lightly modded zed should have no issues but I believe once the mods start adding up you could run into trouble. In my case, I believe the lack of an EGR (thanks to my headers) contributes to the pinging as the EGR is designed to lower combustion temps at those light throttle applications.... so why do I still say you can bypass the det sensor?? well my det sensor works fine and is yet unable to solve the pinging issues I had. Some investgating has led me to believe that the det sensor doesnt work at part throttle applications. And it only monitors from 0-3000rpm... after that, it is not used. Cheers
Re: some answers Ah, thanks for the info and the confirmation. I'll bypass the sensor tonight and see how i go. I really hope its related to my hesitation (i.e. Maybe my engine floods completely with fuel any time that i press the accelerator), but i'd be happy if i could just improve the fuel economy for now. All i know is that i am using so much fuel that i dont think i could possibly be running into lean/pinging conditions. Hope that doesnt happen when i bypass the sensor, but i dont drive it hard so it shouldnt matter that much This is like one of those puzzle games - every time i solve one problem, another one pops up (luckily nothing expensive so far, just annoying more than anything). Keeps me guessing, and striving for the ultimate goal of problem free driving
I have a hard time believing code 34 would make fuel economy that bad In consult are the O2 sensors nice and responsive? Constantly changing values and response to throttle input? Ben
Re: I have a hard time believing code 34 would make fuel economy that bad The oxygen sensor was moving back and forth at idle - you can see it in the pink line on the first graph. But any touch of the throttle would set it to rich constantly for a bit. I noticed also in my graph that the Oxygen sensor stopped fluctuating towards the end though I just went and stared at the engine bay for a good 30 minutes trying to find the DET sensor connector, and guess what, its not where the Z's sensor is I cant find it at all I'm going to go and pick up my gf now, and i'll take the laptop with me. I'll take some readings on the way back and see how i go
Re: I have a hard time believing code 34 would make fuel economy that bad Well, after some procrastination and some 200km tanks of petrol i finally went to see my mechanic. He was able to point out the knock sensor loom for me, which was funny enough, right where it is on the Z (i felt so stupid!) Anyway, I checked it and sure enough, the sensor was buggered. Put the bypass in and WOAH! :thumbsup: the car is completely transformed! I have to learn to feather the throttle when taking off cos i am so used to having to press it halfway to make the car move... Now comes the next problem I noticed tonight that it is pinging (whaddya know, the knock sensor would be useful here). Auto, non-turbo running on vortex 95 octane. I put a bottle of octane booster in and refilled with vortex but it still pings slightly Question: Short of doing the plenum pull (Which might not be quite as bad with the Cedric plenum), and putting in a new knock sensor, why else would it be pinging? Timing too advanced? What other possibilities?
Code 34 will drop you into a knock map. Which is retarded timing and rich as a packer...why is it hard to believe it'll send your fuel economy out the door without a kiss goodbye?
Re: Code 34 will drop you into a knock map. Which is retarded timing and rich Well, thinking back i guess its not so hard to believe. With the retarded timing and rich fuel map the engine was hesitating and missing until around 3000RPM. It was even backfiring at some points because so much fuel was going through it Now that it is running normally again I only put the throttle 1/3rd as far down for the same if not more acceleration. I still notice sometimes a slight hint of hesitation though and it has a lumpy idle. I think there might be a secondary problem of a bad spark or something like that. Might look into the alternator/battery to see if they need replacing. Oh, and now it pings on Vortex 95 + Octane booster. Only slight, but its there none-the-less. Will try Optimax/BP Ultimate next...
