OK, complete rundown, no vacuum leaks period.

Coolant lines are routed properly to bypass both TB, IACV, and FITV,

TPS is good

No CELS.

New (known good) map sensor

New (known good) IACV

FITV deleted (AEBS mani)

timing has been set (properly jumped) three different places, 14,16, and 18 degrees BTDC.

Plugs are new, wires have less than 500 miles on them and are not grounding out or anything like that.

If I start it and don't touch the gas, idles at 1800 no movement. The second I touch the gas when warm (thermo open), it starts to surge from 800 to 2200. If I unplug the IACV (second one, known good), it start to get choppy immediately and jumps from 800 to 1000 with a CEL (naturally) and if I plug it back in after that, it still does the same 200rpm chop with a cel until I reset the ecu.

Where the hell can I go next? A surging idle to me is similar to a tranny with only 1st and reverse to everyone else. I HATE surges and I don't even like to drive it when it is doing it.

 

dude i am having the sam exact problem on my 96 dx if you ever figure it out let me know PLEASE thanx

 

one more question do you have a check engine light and if so what does it say?

 

CEL stands for Check Engine Light, and he has no CEL's

BTW I swear b16 swaps are cursed with crappy idles. When warm mine will stay at about 1200 rpms, when cold it stays between 400-1600 unless it dies. (no cel) no vacuum leak)

 

check coolant level and bleed properly.

 

did you just swap it, or change the intake manifold?
if you did, check to make sure you have the correct TB gasket (physically pull it off and match it up)

 

No, swap has been in there for about 2 years now. Just had it off to change my coolant routing (eliminate all the crap pretty much) becuase I had been searching here and found jdmlifestyles thread on the bypassing helping out with the idle surge. I had it before but not near this bad.

Coolant has no air was bled with the front end jacked up as well. All of the maintenance was done properly and all of the gaskets are new. I know all of the tricks that are normally used but this one is just beyond belief for me.

 

im stumped dude.

 

have you tried a different ecu?

the swap has been in for two years? so has the problem been happening for that long or is it just recent?

 

i fixed my problem and this is what i did take off the idle control sensor there will be a little rod that sticks out the rod should turn very freely mine had carbon deposits on it so it wouldnt turn like it should i took it apart adn cleaned it w some carb cleaner i had teh same problems you have adn that fixed it fo rme try it out and let me know thanx jason

 

Well, what I did was talked to a friend of mine at a local shop here, he told me to block of the IACV completely internaly which I did. Now I have a rock steady idle but it is 1400 rpms and I can't get it lower. I redid the Ether and still no leaks I can find.

The car just started this surge recently prior to changing the head gasket, before that, it would idle rock solid at 800 RPM's no matter what.

Have not had a chance to try another ECU, I will throw my buddies Crome chipped P28 in it tomorrow to see if that helps but as of right now, I am even more stumped as to why I can't lower the idle.

 

How can you bypass the IAC and FITV

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gutted-dx &raquo;</TD></TR><TR><TD CLASS="quote">How can you bypass the IAC and FITV</TD></TR></TABLE>

Best link I know of for a good desciption. It cured many of my problems doing this, now I am down to just one.

http://www.lyonel.orcon.net.nz/tb_bypass.htm