ls/vtec with a b18c1 head. blox tb with stock IM port matched. i had to replace the head due to the other b18c1 head blowing. so once i finally got around to fixing this thing, we started it up and i was having some alignment issues with the throttle cable end matching up with one of the 4 holes on the blox TB.

the throttle cable didnt fit into any of the existing 4 holes so i had to make a new hole that was close to the cable end. it looks like blox provided other holes for you to use if need be, just had to drimmel a slot for the actual cable part, the circular piece went right in.

anyways i got the throttle cable bracket to match up with the bottom of the IM but i only had one bolt. that shouldnt matter since it is in position and tight.

so anyways, the TB doesnt "look" to be opened at all but i dont know that for sure. so when i fire up the car, it sits at 1500rpm roughly, but when i rev it up, it drops back down to the normal 700rpm but then shoots right back up to 1500rpm.

could i have a faulty IACV? i have an extra one lying around from the old head but im not sure whats goin on, i also have a stock TB but it doesnt have the actually pulley part so i know it wont work.

any help is appreciated.

 

bump?

 

it could be a bad IACV,or maybe a vacuum leak somewhere around the IM or TB?

 

this idle problem started when i replaced my b18c1 head. my old head was a b18c1 also.

the IM and TB are being used from my OLD head. so none of that stuff has changed since the swap. there is one nipple on the back of the IM that DOESNT have hose or cap, when i cover it with my finger, it kills the motor. it sucks in air a little bit but its always been like that, even with the old head but i didnt have these problems.

so MAYBE my best bet would be to replace the IACV? i need a pic of the back of the IM so i can show you guys what im talking about regarding that little nipple...unless someone has a pic?

 

only pic i have of my bay...

 

im PRETTY sure i DONT have number 19...that nipple is open.

 

i would try cleaning the IACV before you replace it.

 

for sure, what about the vac diagram tho?

 

so its an obd1 car? check your tps sensor when u put it on right it makes a click sound when u take off,if not that check for a vac leak

 

where is the TPS?

also, i said i was missing the #19 hose pictured above. its an open nipple on the back/bottom of the IM. and YES, it does suck in hair...when i cover it with my finger, the car dies.

 

im missing the Purge Cut Solenoid and the hose that comes with it. numbers 8 and 19 on the diagram above.

 

Are you talking about the nipple where number 18 is going??

having any open nipples or air getting sucked in somewhere is a leak,you will need to plug up that hole or get the purge control solenoid.


plug the hole and your erratic idle should go away

 

the nipple, on the IM will KILL THE ENGINE if i plug it. i have put my finger on the hole before and it dies completely. i need to have it running thru the purge solenoid going to the evap canister.

 

Does the TB help your car out much?

 

i'de like to think so...i got the car this way about 2 years ago. the blox TB is overbored (not sure what mm), the IM is portmatched with the TB so if i replace one, i "should" replace the other ya know?

well actually hold on, i have another IM and TB lying around...this is from the new head that i got, im using the old IM/TB setup cuz its overbored. only problem with the "new" TB is that it doesnt have the spindle part, so its useless.

quick note about my IM, if you've ever looked at a gsr IM you'de notice that it is actually three pieces. there is a section in the IM that is about 3/4" thick and is in the middle of the IM. basically mine doesnt have that piece. dont know why, but its not there.

if you look at the diagram above, you can see the "wedge" piece that im talking about. its right smack in the middle of the IM going from left to right.

 

yeah it will make a difference but thats not the problem if it worked before,you might just need that purge solenoid.
What intake manifold are you using?
If its butterfly intake mani then are you using the solenoid for the BF?

 

its the stock GSR IM, i dont know what the BF is.

even with the old head, when the car was running, i never had the purge solenoid. my idle back then would be like like 500rpm.

 

its going to be a vacuum leak no doubt about that

 

im hoping! cuz everything is EXACTLY the same as before...just a different head.

 

wait,does it go up and idle at 1500+ really quick and then go back to maybey like 900? and then it keeps doing it??

 

call the guys in taiwan.

 

its more of a constant 1500-1800rpm...only SOMETIMES does it fluctuate from stock idle to high idle.

if i sit at idle, punch the gas real quick and let go real quick, it drops back down to stock idle for like 2 seconds, then kicks up to the higher idle.