My_EFsedan

Last Thursday my cousin and i swapped in a B20vtec in his 89 sedan..car previously had an LS so everything was there. motor went in. has a 99 obd2 head with the obd2 intake manifold.

that manifold with the matching TB has that sensor that sits on top..which doesnt plug anywhere on his harness and for some reason it makes noise like its leaking air from there. his car has idle fluctuating from 1k to 15oo. up and down on warm up and normal temp. the obd2 also doesnt have a Intake Air Temperature Sensor, its just a blocked off hole. so the car gives a Check Engine like for #10

10: IAT Sensor (Intake Air Temperature)
defective circuit or unplugged / defective sensor

so yesterday we bought an obd0 intake manifold since the car is an obd0 and tends to run off alot of vacuum. we use an LS TB since it didnt come with a matching TB. it also has a IAT sensor, i swapped the rails/injectors over, TB and IACV which doesnt fit and only one 12mm bolt would line up. which one do i need?

so after i swapped everything over installed it onto the car..got everything plugged in started it up, car throws the code 10 again even after i took the battery ground off. i changed the IAT sensor with 2 others and still the same..unless the plug is wrong ? (can someone identify the wire color for it?)

car fluctuates on idle still but every little unlike before. but now it fluctuates at 15oo-2k..the manifold, while car is on, also sounds like a fat *** vacuum leak from his thing on the manifold..


but no air coming from it..i cant seem to get this fluctuating to stop and get the idle to go down.

the PCV valve is their but doesnt plug into anything cause the b20block doesnt have that black box on the block..is that safe?

also i need a vacuum diagram for an obd0 b16 manifold if anyone has it.

any help is appreciated, thanks!

Video of this problem tomorrow!!

EF-8SiR

Is your throttle cable adjusted to spec?
Have you played around with your Idle Adjusting screw?
Is your TPS/throttle angle sensor calibrated to spec?

I had my idle problem.. from 1500rpms to 2000rpm,
all i did was adjust my idle screw untill it went down, checked for any vacuum leaks & the high idle is now fixed.

IndySporty

disconnect that thing that goes to the throttle body in the front you have circled and find an IACV from an OBD-0 manifold that will bolt on with both 12MM bolts, that could be causing a leak. Also, check the FITV. On your manifold it's either right under the TB on the manifold itself or it's on the bottom of the TB. Sometimes you just have to bypass that one completely by putting something between it and the manifold. If you have a properly working IACV that one is pretty much useless anyway. It will cause a rapid idle fluctuation while the IACV will cause a slow fluctuation. Good luck this is the bane of Hondas and usually takes a little work to correct.

My_EFsedan

ef-8sir- the cable is not too loose and its not too tight where it would pull the valve. idle screw is all the way to the right if you would look straight at it. how would i "calibrate" it to specs? i mean the tps was never touched since we bought the running car a few months ago..

indysporty- i dont understand what you mean. its also hard to find an obd0 iacv and i dont know where to get a new one at. i changed the iacv from my car and put it on his to try and troubleshoot, but that ugly loud leak sound is still there. the fitv is adjusted all the way in. its on the manifold, i also have the coolant port that aims down blocked off cause i dont know where it goes. what do you mean by bypassing it by putting something between the mani?

the pix above is my other cousins b16 swap sedan..

this pix is the b20vtec on my cousins sedan thats having this issue.



and PCV doesnt go anywhere

My_EFsedan

well i fixed code 10 cause the connector inside the plug was pushed back where it didnt touch and read..but now throws a code 14 for iacv..the idle flucuate very little on idle without hitting the gas, but when i rest my foot on the pedal just a tad bit, it fluctuates hard..i have a video but its not letting me upload right now..i will probably get a new intake manifold gasket for the hell if it..and see if that will slightly put down the vacuum leak..i will report back.

My_EFsedan

i fixed the code 10 and gave me 14, just now i fixed code 14. so no more check engine light. it idled consistently at 2k and i took it around the block, came back and now the car fluctuates from 1k-2k..

My_EFsedan

help..

91sedan_kid

can anybody please help me with this problem?!

EF-8SiR

ADJUST (turn) your idle adjusting screw, for me.. i got out my flathead, while the car was idling WARMED UP.. All i did was twist it to the right untill my idle dropped from 2000 rpms to 750rpms, anywhere from 700-800rpms is good. Try it

~sp33~

Sounds like my problem. Check out the thread i made, there's also a vid.

Currently it still idles around 1100 rpm, but doesn't fluctuate anymore.

https://honda-tech.com/forums/showth...504&highlight=

How would adjusting the idle stop the idle from bouncing? Fair enough if it was idling steady but high, though it's not.

EF-8SiR

code 14.. you replaced the EACV?

if the idle speed can still not be adjusted to specification, and the led does not blink "code 14" after you have just replaced the EACV..

SUBSTITUTE a known-well-operating ECU and test. borrow, use, buy whatever works.. an ecu that is known to be GOOD, plug it in, warm the car up untill the fan comes on and see what your idle is at. Does your thermostat operate currectly? ALSO, make sure your not operating any add-ons, such as the heater, headlights, radio, etc etc.

if the fully functional ecu is in & you still have a high idle, come back here and post

My_EFsedan

like i stated that screw has been turned alllll the way to the right. the code 14 was the plug being wrong, i plugged the green on back on and code went away..

EF-8SiR

"car fluctuates on idle still but every little unlike before. "

but yes, that won't help the fluctuating of the idle.

If you can, get your hands on a vacuum pump/gauge.

what i would do:

adjust idle speed,
check for breaks in the hoses/leaks
check for bad connectivity between sensors,
EACV and it's mounting o rings,
alternator,
and fast idle valve.

EF-8SiR

sorry, just trying to help, heres a few from my pdf.









hope this helps, good luck with the problem

My_EFsedan

thanks^

so we got a new b16 manifold gasket. scraped off the old one and make the surface flat. installed that. rerouted a few vacuum hoses..started up perfect. warm up was at 1k normal was at 900rpm.. no more fluctuations or bogs, thanks everyone and their imputs.

craphatch

on my b20 vtec that is gone and has a block off plate that is but in its place to block off the holes...

Gabe87CRX

I know this thread is old, but it has helped me find out what I need to do to fix my idle surge...

Thanks guys!!!

My_EFsedan