Jump to content
SAU Community

Recommended Posts

Hi all,

I've got a r33gtst with a haltech platinum plug in, today I installed an air temp sensor and it seems like the car is running rich now. I don't understand why it would affect the tune when both timing and fuel correction is disabled for the air temp sensor. 

What I've done is, deleted the MAF, wired up the MAF signal and signal ground to the air temp sensor and re-pined the MAF signal to the air temp sensor signal on the ECU connector. The air temp sensor seems to be working perfectly. 

Unfortunately I don't have a wideband so can't say for sure that it's running rich, but there are flat-spots everywhere now and the popping and crackling on decel are a bit louder now so my guess is its running rich. 

The car is tuned on VE and I had deleted the MAF ages ago so I know that's not the issue. If anyone could shed some light on this it would be much appreciated!  

Did some more reading online, seems like people are tapping the MAF ground into the coolant sensor ground. Doesn't make sense to me needing to tap a ground into a ground but I did it anyway... Still didn't fix anything. 

Pulled the air temp sensor out and it's all back to normal again. I'm out of ideas. 

I'm using the, I guess you could call it 'standard' delphi air temp sensor. The ecu picked it up straight away as its using the factory GTR air temp sensor wiring now, I checked the main setup for inputs and there was already values there for the air temp sensor. It is a pretty liner table from 0.5 volts (120 degrees C) to 4.47 voles (17 degrees C). Do I still need to change this?

I still think it's really weird that its affecting the tune though. I thought it would only affect the tune if I enabled the correction tables?

Umm from memory it was sitting around 45-50 degrees when idling in traffic and got down to low 40's when driving around. Does that sound right for stock turbo (10psi) and stock sidemount? I wasn't brave enough to push it hard as the tune felt terrible. 

Does pipe is correct (see #3 below) but I wanted to add two other things:

1) Get a wideband - ASAP. I am running their CANBUS. In all honesty it makes no sense to have spent this much on a Haltech and not have the wideband. It opens SO many more tuning and safety options that you don't have now and I would say this is CRITICAL for any standalone.

2) I also used a AFM wire back to the ecu for one of my sensors and just repinned at the ECU so there is not an issue there unless you crossed some voltage (but it sounds like you didn't because you are at least getting "normal" values).

3) Did the R33 GTST not have an air temp sensor? If not, then surely the ECU was assuming some value for this input in it's calculations of air density (air temp is one of the calculations). Basically they were assuming air temp didn't change I guess? If this is the case and you ADDED a sensor where one didn't previously exist, and you added it as an input (properly) and scaled it (properly) then you will need to retune the car for sure to match the ACTUAL air temp.

 

A final FYI. My air temp sensor is zero mapped up until around 120-130F and down to 50F. Meaning it only changes the tune on fuel % added above or below those values respectively.

Point 3 makes sense about giving the car an actual input vs it's previously assumed ones (GTST's don't have air temp sensors). I just thought it would carry on as it was previously, using the assumed figures, if I didn't activate the correction tables. 

I agree about the wideband, it's very high on the priority list. My poor R33 has a few other things to fix first but I'll get it before I add any real performance mods (currently all I have is a cat-back & a bit more boost).

 

those temps appear some what "correct", if the car is doing other stuff then there is some other correction being applied.. because the factory haltech base map only shaves timing and pulls out fuel above 70 degrees Celsius...

you need a wideband!

Another quick test is to pull logs of injector duty cycles (or time) at known values to see what it is doing when you run the old way with no IAT vs the new way with IAT mapped. At least this could get you back quasi on target running. Nice thing about a wideband are the added protection in the engine protection menu. I set my car so that it will protect the engine (raise fuel % and lower boost) when I'm 12.5 AFR or higher over 15 psi. This will eliminate any potential fuel pump failures from giving me issues there.

I'm quite confident it's changing the map somehow.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I had 3 counts over the last couple of weeks once where i got stranded at a jdm paint yard booking in some work. 2nd time was moving the car into the drive way for the inspection and the 3rd was during the inspection for the co2 leak test. Fix: 1st, car off for a hour and half disconnected battery 10mins 4th try car started 2nd, 5th try started 3rd, countless time starting disconnected battery dude was under the hood listening to the starting sequence fuel pump ect.   
    • This. As for your options - I suggest remote mounting the Nissan sensor further away on a length of steel tube. That tube to have a loop in it to handle vibration, etc etc. You will need to either put a tee and a bleed fitting near the sensor, or crack the fitting at the sensor to bleed it full of oil when you first set it up, otherwise you won't get the line filled. But this is a small problem. Just needs enough access to get it done.
    • The time is always correct. Only the date is wrong. It currently thinks it is January 19. Tomorrow it will say it is January 20. The date and time are ( should be ! ) retrieved from the GPS navigation system.
    • Buy yourself a set of easy outs. See if they will get a good bite in and unthread it.   Very very lucky the whole sender didn't let go while on the track and cost you a motor!
    • Well GTSBoy, prepare yourself further. I did a track day with 1/2 a day prep on Friday, inpromptu. The good news is that I got home, and didn't drive the car into a wall. Everything seemed mostly okay. The car was even a little faster than it was last time. I also got to get some good datalog data too. I also noticed a tiny bit of knock which was (luckily?) recorded. All I know is the knock sensors got recalibrated.... and are notorious for false knock. So I don't know if they are too sensitive, not sensitive enough... or some other third option. But I reduced timing anyway. It wasn't every pull through the session either. Think along the lines of -1 degree of timing for say, three instances while at the top of 4th in a 20 minute all-hot-lap session. Unfortunately at the end of session 2... I noticed a little oil. I borrowed some jack stands and a jack and took a look under there, but as is often the case, messing around with it kinda half cleaned it up, it was not conclusive where it was coming from. I decided to give it another go and see how it was. The amount of oil was maybe one/two small drops. I did another 20 minute session and car went well, and I was just starting to get into it and not be terrified of driving on track. I pulled over and checked in the pits and saw this: This is where I called it, packed up and went home as I live ~20 min from the track with a VERY VERY CLOSE EYE on Oil Pressure on the way home. The volume wasn't much but you never know. I checked it today when I had my own space/tools/time to find out what was going on, wanted to clean it up, run the car and see if any of the fittings from around the oil filter were causing it. I have like.. 5 fittings there, so I suspected one was (hopefully?) the culprit. It became immediately apparent as soon as I looked around more closely. 795d266d-a034-4b8c-89c9-d83860f5d00a.mp4       This is the R34 GTT oil sender connected via an adapter to an oil cooler block I have installed which runs AN lines to my cooler (and back). There's also an oil temp sensor on top.  Just after that video, I attempted to unthread the sensor to see if it's loose/worn and it disintegrated in my hand. So yes. I am glad I noticed that oil because it would appear that complete and utter catastrophic engine failure was about 1 second of engine runtime away. I did try to drill the fitting out, and only succeeded in drilling the middle hole much larger and now there's a... smooth hole in there with what looks like a damn sleeve still incredibly tight in there. Not really sure how to proceed from here. My options: 1) Find someone who can remove the stuck fitting, and use a steel adapter so it won't fatigue? (Female BSPT for the R34 sender to 1/8NPT male - HARD to find). IF it isn't possible to remove - Buy a new block ($320) and have someone tap a new 1/8NPT in the top of it ($????) and hope the steel adapter works better. 2) Buy a new block and give up on the OEM pressure sender for the dash entirely, and use the supplied 1/8 NPT for the oil temp sender. Having the oil pressure read 0 in the dash with the warning lamp will give me a lot of anxiety driving around. I do have the actual GM sensor/sender working, but it needs OBD2 as a gauge. If I'm datalogging I don't actually have a readout of what the gauge is currently displaying. 3) Other? Find a new location for the OEM sender? Though I don't know of anywhere that will work. I also don't know if a steel adapter is actually functionally smart here. It's clearly leveraged itself through vibration of the motor and snapped in half. This doesn't seem like a setup a smart person would replicate given the weight of the OEM sender. Still pretty happy being lucky for once and seeing this at the absolute last moment before bye bye motor in a big way, even if an adapter is apparently 6 weeks+ delivery and I have no way to free the current stuck/potentially destroyed threads in the current oil block.
×
×
  • Create New...