FITV bypass on B16A OBD1

[EGfan]

Guys,

Need your feedback on this mod. I recently bypass my FITV coolant line, and also did a blocking plate to shut off the air regulation. I realise that my idle is quite high now, 1.5K. Even when i reach normal running water temp at 80 degrees the idle doesn't drop. I also bypass the coolant to the IACV as well. Is it normal to idle so high after this mod?

Anyone used intake manifold thermal gaskets? Experience any leaks? Do you need to use OEM gaskets on both sides as well? need to change to longer studs?

Thanks

 

[shiroitenshi]

You mod the idle system, of course idle will be constantly high, compensate with TB idle screw.

if use hondata gasket/aftermarket, should be without the ori gaskets. check pressure of intake at idle@800rpm, should be within 300 or 400mbar, if a lot higher, it is possible there is a leak.

---------- Post added 12-28-2010 at 12:02 AM ---------- 6 hour anti-bump limit - Previous post was 12-27-2010 at 06:50 PM ----------

oh, forgot, if idle constantly high, check your tps too. might be a reason your iacv not working properly. Should be 0.5v fully closed. Another way to test for leaks without equipment is by fully closing the idle screw, the engine should die off, or idle very low, 500
Rpm or less if rpm still high, maybe possible leak somewhere.

Nowdays got equipment, I use equipment instead, so forgot this method until just now. I don't think the gasket is the source unless it's badly made. More likely hoses. Very rare the honda intake crack.

 

[EGfan]

Hi shiroitenshi, thanks for you feedback. These are the things that i have checked.

TB idle screw. Jump the service connector, idle till 80plus Celsius, unplug the IACV, adjust the idle screw. No differece in idle. Screw all in also same, unscrew everything also same. I have cleaned the TB before and i cleaned the idle screw hole.

TPS. i'm using the OmniPower TPS as my ori was faulty. Adjusted to 0.5v at close position. However, when i datalog using EcuControl, at WOT, the TPS reading was only 92%?? Adjusted the TPS to the max, only can get 97% at WOT. But does not lower my idle also.Not sure which reading i should use?

What equipment do you use to test?

You mod the idle system, of course idle will be constantly high, compensate with TB idle screw.

if use hondata gasket/aftermarket, should be without the ori gaskets. check pressure of intake at idle@800rpm, should be within 300 or 400mbar, if a lot higher, it is possible there is a leak.

---------- Post added 12-28-2010 at 12:02 AM ---------- 6 hour anti-bump limit - Previous post was 12-27-2010 at 06:50 PM ----------

oh, forgot, if idle constantly high, check your tps too. might be a reason your iacv not working properly. Should be 0.5v fully closed. Another way to test for leaks without equipment is by fully closing the idle screw, the engine should die off, or idle very low, 500
Rpm or less if rpm still high, maybe possible leak somewhere.

Nowdays got equipment, I use equipment instead, so forgot this method until just now. I don't think the gasket is the source unless it's badly made. More likely hoses. Very rare the honda intake crack.

 

[shiroitenshi]

I used the Bosch FSA 720 pressure sensor. If you can't reduce the idle down to less than 800 with the IACV unplugged, then there's definitely something wrong. Congratulations on noting that you have to unplug the iacv to do the test, I forgot that lol. Sorry. If you have a spare iacv, try replacing that, or if you don't, try removing the iacv and plugging the hole with your finger, and try reduce the idle like earlier, I suspect the iacv jammed(cannot close fully), and maybe your leak is from there. If not, you've got a quite a bit work to do tracking down the leak.

Tps percentage always have to calibrate first, this is true for vafc, the emanage blues and hondata. I think ecucontrol should have that as well, reason being that WOT is not exact for tps sensors, as long as it's below 4.5v, it should be okay. I get readings with differences up to 0.2v, so I think that's why for tps percentage readings always have option to calibrate.

Btw, mind telling me more about ecucontrol? Haven't seen it used on honda before.

 

[EGfan]

One thing i tried was covering the top hole in the TB, i think that leads to IACV? and the idle went lower. Does that mean the IACV is stuck?

So i guess i will have to calibrate the volt to 0.5v at closed position then..

Ecucontrol is a datalogging software that taps into the ECU and displays the parameters of your engine. Functions are similar to greddy infotouch. However, it only supports ECUs that runs on Crome or Uberdata (Chip) for OBD1. To datalog, you need to DIY the serial to USB mod on the ECU which i used the nokia data cable. You can monitor your water temp, air intake temp, rpm, speed, vacuum, tps, a/f.

 

[shiroitenshi]

Note, I'm so used to calling lower atmospheric=vacuum thought it's not exacly accurate, so bear with me, since I find it hard to change LOL.

There's only two ports on the top of the TB, (if you're talking the ori honda B16A TB) the charcoal canister port and the map sensor port... there shouldn't be an IACV port, because IACV port from intake end up at front of TB throttle plate. Which port do you mean? As I remember, the charcoal canister port isn't vacuum (low atmospheric, to be exact) I left mine unplugged last time without issues.

Thanks for the Ecucontrol information. I've heard of software called Ecucontrol, but that was for evo and wrxs, connects throught the obd2 a data link connector via a dongle. I thought somehow you got it working on a honda.. heh. Confused for a moment there. Should be the same though, the tps percentage has to be calibrated, try read the manual on how to do it. For most cars, usually throttle off, set, throttle full, set. I think your ecucontrol like the HUlog right?

What do you mean you have to reset the 0.5v TPS?, I thought you said already did? IACV stops working when TPS is more than 0.6v.

Well, to confirm, just borrow one spare iacv unit to test. or just fully close the IACV port (after you remove the IACV) (with finger if it's not permanent, ha ha), just one of the holes, since the other hole is not vacuum, since it's leads to the front of throttle plate Since you can get reading from the CN2 port, read the map sensor pressure from there, that one is quite useable assuming your map sensor is healthy.. honda cars idle around 300-400mbar if you manually set the rpm to 800 without iacv compensation and without leaks. Convert the unit with google if the unit is not in mbar for yours, though I think it should be able to be set in the software.

Let me know how it works out.

 

[EGfan]

Sorry, i meant the 2 holes inside the TB, in front of the throttle plate. So if i cover that up and the idle drops, does it mean its the IACV?

 

[shiroitenshi]

Most likely, but better test with the coolant pipes connected to IACV, since I've never tried removing them, so not sure what happens to the IACV when it's not connected. Perhaps the pipes heat up the IACV so it knows when it's time to close fully. Try it out and see. I'm also curious about the function of the coolant pipes on the IACV.