B16B ITB TUNING

Hi Guys,

Needed abit of help with my car its a B16B with ITB's running a Hondata s300 ECU, I'm having issues with it idling or when coming to a stand still the car has to be revved in order for it to idle other wise the car just dies out apparently the ITBS need balancing and it has a misfire at low speeds but fine on full throttle, there is no engine light on car drives spot on just as described above, I was wondering if any one with ITBS knows how to balance them or knows of any one who has experience with working on ITBS preferably as close to Buckinghamshire as possible.

Thanks in advance

From byp racing developments

Fron S2KI.com

Bottom line is don't try to think running TPS-only to avoid tuning problems. You may get it tuned in the ballpark sooner with TPS only but you'll end up very difficult to fine-tune it because in every different running environment, your TPS tuning will be off. The problem is that TPS doesn't measure air-flow but "assumes" it. Try every possible attempt to use TPS plus MAP sensor. I don't know about the AEM, but TPS-blend helps fine-tuning a lot. Even then, use as much MAP sensor reading as possible.

The key to running MAP sensor on ITB is to build some kind of vacuum tank to store and smooth out vacuum pulses from each runner. The size and even shape makes a huge difference in the outcome. Too big a tank you loose throttle response. Too small a tank you get pulsive MAP sensor reading and may require too much TPS-blend to hide the problem. I'm relatively new to the S world and know that the S runs a vacuum tank from the factory. I don't know if it can be used for the ITB.

The best and perhaps the easiest way is to fabricate your own vacumm tank with some brass pipes. Get a brass pipe (1/4" diameter IIRC, at least 2ft long), a fitting brass end-cap, and a hose barb fitting the pipe (for brake booster) from Home Depot. Get a small brass pipe from hobby store (diameter big enough for small vacuum hose, long enough to make 5 or more barbs). Cut the big brass pipe into length (about 18", require tuning), drill 4 holes equally spaced out and solder in 4 small brass pipes for the 4 vacuum hoses to the runners. Use pipe solder or even regular solder. Drill one hole and solder in a small brass pipe for the MAP sensor (and more holes if more vacuum devices). Solder in end cap on one end and the other with the big barb for vacuum booster. This may sound quite a bit of work but trust me a well-tuned vacuum tank saves you a big deal of headache by not needing to run more (or all) TPS to avoid MAP sensor reading problems

Thanks alot for the detail reply, the only issue is the tuning company is not based in the UK but when searching did find this https://www.facebook.com/pages/Peop...h-BYP-Racing-and-Developments/621385121239792 bit worrying but i wont be using them so never mind.

With regards to the Vaccum Tank I have a blox vaccum manifold fitted to the car i dont know if thats meant to act as what you are describing will have to have a look when i get home if not create one as you mentioned above, Ive only recently brought the car and most work was done before and I dont know much at all with regards to ITB guess i will learn now lol.

Thanks again for the reply

If you want I can review your map and let you know if it is likely a tuning issue.

You will need a Synchronizer to balance your ITB's. What brand ITB's have you fitted?

That would be a great help that way will know whether id need to send it to get tuned again or not, how would you review my map?

Also i seen a few videos on youtube to with regards to the synchronizer will more then likely order one on my days of and get cracking.

Email me your map file to AP-Performance@hotmail.com

Cheers will do will be on Wednesday when im with the car

Hi where in bucks are you ? I'm based in Fleet, Hants, I have lots of experience with different Itb's on Hondas, I have a synchroniser, as others have said it very difficult to get Itb's to idle on a map sensor, they much prefer throttle pot only.

Give me a call
Tony 07799717800

We achieved perfect idle and oem driveability with the ITB kit we fabricated using oem map and TPS sensors

Are your ITBs in an airbox or open?

As said they need to be properly balanced as a bare minimum with a synchronizer and then it's all in the mapping to achieve smooth and stable operation

Car was tweaked by daz at dnr and retuned however now the car is idling at 3k and when cold surging between 1k n 2k this only started to happen once i came of the motorway was fine outside the garage. So trying to find out whats wrong with it now

Who does your mapping Tony?

Just a heads up now all sorted was mapped and itbs balanced and the surging idle was due to a know on the itbs needed to be loosened a little running alot better now

What ITB's are they?