Alright, long story short, i just got my built b16a back in my car last week and went to fire it up and everything went great. No leaks or any funny issues at all. I took the car on a 30 minute drive just to flush out any bs that got into then engine it while assembling it.

I got the car home and went to calibrate my tps sensor via hondata and that is when my problems started. I have a pretty bad idle surge that seems impossible to fix at this point. At first it seemed obvious it was just tps related because that was the only thing i changed since my problem happened but i was mistaken. I tried about everything in the book to fix this, cleaning iacv, vaccum testing, checking voltage at every sensor to make sure everything is getting the proper power. I even reflashed the original basemap my tuner sent me to make sure i didnt accidentially screw anything up while i was calibrating the tps.

Me and my tuner cannot seem to figure this bug out so if anybody has any recommendations on what it could be that would be greatly appreciated!!!

 

Explain the surge. Is it getting to a specific RPM; like say, 3k and holding, or is it bouncing/fluctuating?

 

Somehow air is getting in past the throttle plate.

• MAP, IACV, FITV, and IAT sensors all have their o-rings installed?
• What throttle body and intake manifold are you using? Is the throttle body gasket damaged or installed incorrectly?
• What happens when you unplug the IACV? What happens when you put your finger over the IACV hole inside the throttle body?
• If you still have an FITV, have you made sure the large screw inside hasn't backed out?

 

i tried unplugging the tps, iacv, iat all with no change in the idle. I did a vaccum test and found no leaks whatsoever. I also took off the throttle body and cleaning it out good. I also tried putting my finger over the hole for the iacv with no luck. I am using a stock b16a intake manifold with a stock throttle body.

 

when the engine is cold it fluctuates from 1500 down to 1000 rpm or so. When i drive the car and get heat in the engine it goes from 1000 down to about 200rpm virtually stalling the engine.

 

Are you running a base map or have you tuned yet?

 

Can you post up a calibration and datalog of the issue?

 

Just a base map. I know its not tuning related because the car was running fine until i started messing with the tps. I took the car on a few drives on this basemap with no idle problems.

 

Here you are sir.

 

Can you post the calibration and datalog files instead of just a screenshot?

Just going off your screenshot though, it looks like the oscillation of the RPM lags behind the oscillation of the AFR. Your AFR goes super lean (around 20:1), then the RPMs start to dive.

Are you running in closed loop? How is your wideband wired in and what are the settings in the tune? Try running in open loop and see if that fixes it.

 

Dax beat me to it. Lol! I was going in the direction that you were running lean.

 

hondatech wont allow me to post this type of file For the calibration. Can i email you them?

 

Sure, I sent you my email address in a PM.

 

i unplugged the aem wideband sensor and the car idles PERFECTLY. This makes no sense because i am running in open loop so the sensor shouldn’t have anything to do with how the car runs. Im just so confused at this point but atleast i can drive the car around without it surging all over the place

 

Did you upload the tune to the ECU? I've made this mistake before by adjusting things in SManager then forgetting to click the upload button. Try reloading the tune, making sure that you have closed loop selected.

 

i have multiple basemaps from my tuner which are in open loop. The idle surges on all of them but if i unplug the sensor the idle will hold solid. I have my wideband wired into the D10 ELD on my hondata s300. Could this possibly be a wiring problem?

 

It could be. It doesn't make sense that if the tune is in open loop that the wideband would control the ECU in any way. If everything is wired correctly and the tune is set up for open loop, the signal going into D10 is only used for datalogging or lean protection.

 

Yeah me and my tuner are lost on this thing. It makes no sense that unplugging the wideband has any effect on how the engine runs since its in open loop. Im going to look over the wiring once more and triple check everything is wired correctly. The part that is even weirdo is that this problem occured out of no where. One day i just got home (car was running perfectly fine) and i went to start it up about an hour later and it had a crazy idle surge. I even tried putting a new sensor in it with no luck.

 

Where is your wideband controller grounded?

 

[QUOTE=Txdragon;52200945]Where is your wideband controller grounded?[/QUOTE
it is grounded to a bolt underneath the dash. I have hear you should ground it to the thermostat housing but i have had it setup the same for almost 3 years now without any problems. It probably wouldn't be a bad idea to change the ground just to rule that out.