is it a good idea to bypass IAC and FITV coolant lines .....well considering if you have im insolated gaskets

 

umm dude, just to let you know, 96+ Gsrs do not have FITV, I bought a jdm 00 TB and it has none too.

If you bypass your IAC, your car will run pretty fucked up. it is used to maintain correct air levels to make sure your idle is normal and not surging.

IMHO, you can bypass the FITV if you want, but leave the IACV unless you want a fucked up running car.

BTW what are you trying to accomplish by bypassing these lines?

 

you definatey cant bypass the IAC, or the car pretty much wont idle at all. and bypassign the cooling lines on the throttle body, will not show enough gains, or any, to waste your time. some domestic guys do it because they think it will keep the air coming into the throttle body cooler.

 

hmm i think you guys misunderstood for SIAC....bypassing the SIAC's coolant lines, not the whole IAC.....there are two of them one in and one out of the SIAC...

SIAC's coolant lines are use to cool down the SIAC's temp under the hood...SIAC itself controls by ECU and not by coolant lines...FITV is mechinically controls by coolant's temp at start up

im talking about the removal of coolant lines here, not sensors or valve at all

 

bump

 

I bypassed my IAC, and I just raised my idle, no problems here. The reson I bypassed it tho is because its bad, or something is cuz Im throwing an IAC code. Could the hondata gasket be the cause for this?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yeegsr &raquo;</TD></TR><TR><TD CLASS="quote">hmm i think you guys misunderstood for SIAC....bypassing the SIAC's coolant lines, not the whole IAC.....there are two of them one in and one out of the SIAC...

SIAC's coolant lines are use to cool down the SIAC's temp under the hood...SIAC itself controls by ECU and not by coolant lines...FITV is mechinically controls by coolant's temp at start up

im talking about the removal of coolant lines here, not sensors or valve at all</TD></TR></TABLE>

In that case why cant you just cap off the lines and put a hose clamp on it? I don't see the gains in doing this, but hey it's your car.

 

I have my fitv. and iac both bypassed to help with keeping the air comming in cool. no problems. works great.

 

How are you OBD-1 guys bypassing the FITV without it high idling all the time? If the wax plunger doesn't heat up enough to expand the plunger, how is the idle speed gonna come down?

OBD-2 throttle bodies are fine since they don't have the FITV.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IN VTEC &raquo;</TD></TR><TR><TD CLASS="quote">How are you OBD-1 guys bypassing the FITV without it high idling all the time? If the wax plunger doesn't heat up enough to expand the plunger, how is the idle speed gonna come down?

OBD-2 throttle bodies are fine since they don't have the FITV.</TD></TR></TABLE>

yes, FITV somewhat idling high if bypassed...only for some case such as cold weather states...snowing areas....idle at start up does mechanically controlled by FITV's coolants temperature. This is when wax plunger coming in...when wax plunger getting warmer, it slowly closing the FITV and blocking the air coming then idle get lower, since wax plunger allows less and less air when it getting hotter an hotter.......if you live in california the whether is mostly like aint cold therefore the wax plunger ain't that cold also....bypassing the FITV meaning no coolants inside FITV at all, so the plunger is not fully opened...and when the engine start it suxs cold air inside FITV and cool down the FITV and plunger (this is where the idle usually constant, but whether like summer can be use to counter the coldness of the plunger and drop idle lower) instead it slowly gets warm up by coolants of the motor. hope this is clear to you...

so in hot whether areas...bypassing FITV and SIAC aint a bad idea....

 

Thanks for the re-iteration on the principles of action of the FITV, but I don't need another explanation.

I just wanted to hear some real-world experience with idle speeds and having the FITV's coolant supply bypassed. I never got around to doing any extensive testing with mine before I got tired of playing around and switched to an OBD-2 throttle body.

My brief experience with it was when I bypassed the lines and it high idled at 1300rpm to 1500rpm for the 5 minutes or so I had it running in the garage.

My opinion on the matter is that if you're gonna bypass the lines, you should switch to a JDM ITR throttle body to get rid of the FITV but still keep the OBD-1 EVAP purge port on the top of the throttle body, or fabricate a block-off plate to take the place of the FITV (and use an OBD-2 throttle body gasket).

 

to get rid of the high idle at start up, i cut out some alumnium from a beer can and cut it into the shape of the fitv where it mounts to the throttle body. basically i made an aluminum gasket that gets sandwiched between the fitv and throttle body. i also used some permatex blue just to make sure there was no air leaking. then i bolted up the fitv to the throttle body and there was no idle fluctuation after cold start-up.

 

Now that I think about it, I don't think you can use an OBD-2 throttle body gasket with an OBD-1 throttle body without producing a vacuum leak.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IN VTEC &raquo;</TD></TR><TR><TD CLASS="quote">Now that I think about it, I don't think you can use an OBD-2 throttle body gasket with an OBD-1 throttle body without producing a vacuum leak.</TD></TR></TABLE>