calvin924597

Just bought a 99 EJ8 5 speed to replace my EJ8 auto. Got the car home, started throwing a CEL.

symptoms are:
Idles at 1500
Give it a little gas, gets really jerky and rough
let go of the gas, goes down to about 1000, then back up and down.

Im figuring it's a code 15/P0505, but I took off the IACV and it looks brand new inside. I tried adjusting the idle screw, but it doesn't go any lower. I already tried spraying carb cleaner on some of the hoses to check for vacuum leaks but that doesnt seem to do anything either. I took off the intake and put my finger over the small port in the throttle body and the car didn't stall, it just slowed down a bit. does that mean I just have a massive vacuum leak somewhere? I need to drive the car to school tomorrow so any advice would be very appreciated. Thanks!

lthao61

check coolant level
pull exact codes and diagnose
check for vacuum leak around intake manifold or TB

TUR3Ovtec

you check your TPS sensor? I got the same code on mine and i'm waiting for a new IACV to come in! Good luck man!

Mikey3000

sounds like a fuel problem. you need to figure the code out before anyone can help.

calvin924597

How do you test the TPS sensor? unplug it and see how it runs without it?

thanks for all the suggestions.. ill try to check the CEL code

Mikey3000

a TPS problem alone wouldn't cause the jerky and rough ride you are experiencing. the TPS is just one parameter that gets its signal sent back to the ecu to pick a map, and its not even that important.

calvin924597

Should the engine stall when I cover the lower port of the throttle body with my finger? There definitely is lots of vacuum, but the engine just slows down a little bit

calvin924597

Bump. Still havent been able to get a scan tool for the CEL. Could it be the O2 sensor? I think im running a bit rich.

97ej6dx

Either Fast Idle Solinoid,TPS or IACV both have shown the same Jerky ON or OFF no in between for me. Make sure the connection to the IACV is correct then there is a way to take apart the fast idle solinoid. that was the KEy for me. take the fast idle solinoid off and you can get i belive a flat head screwdriver and tighten the spring back down. But The system of the IACV and the Fast Idle solinoid are on the same cirtcuit so check power from both but i have a feeling its the fast idle solinoid

calvin924597

Do 6th gen civics have a fast idle solenoid?

97ej6dx

yes i have a 6th gen its going to look similar to this.
They call it a valve i suppose it is more of a valve but you take it off and there is a screw that has a flat head inside it on a spring you tighten it untill its tight then put it back together.

calvin924597

Ah gotchya. I have a d16y8 with the side draft intake manifold though, so it it in a different location? thanks for the help

Also, in other news. I checked the CEL, its a code 14 which is for the IACV. But the IACV is brand new, so I don't think its that. I added more cooland and tried to bleed the system, and the idle improved. It now idles at about 1100. I unplugged the TPS and ran it, without the TPS it idles at 1600. Does this mean I've got a bad TPS?

97ej6dx

nope the TPS just controls The Throttle Position its supposed to act like that. The IACV and the FITV are on the same system so if one acts up it will tell you its the IACV. It def sounds like the Fast idle valve now The fast idle is connected only by the lines to the IACV no electronic connection thats why it wont tell you its the FITV because there is no sensor or plug

calvin924597

Thank you so much!!!! I would have never figured it out without you guys... thanks!! :D

97ej6dx

no prob I actually found that info out on a forum a few years back and I never would have found that out either. I belive the person was a Honda certified mechanic and did swaps on the side so he knew the whole car like the back of his hand. ( or the palm depending on what his extracurricular activities were ). lol

calvin924597

Ok so here's an update. Cleaned FITV out, put it back in, reset ecu. Ran great for 15 minutes and then started doing the jerky throttle thing again. It now idles at about 1100 with the idle screw tightened all the way. Another symptom is that if i shut the car off and turn it on right away, the jerkiness goes away for about 10 minutes. And its developed a new problem too... when I put it into neutral and coast to a red light, the idle goes up to about 2000, drops suddenly to about 900, and goes up and down again.

haha this is so frusturating. anyone got any suggestions? thanks

HondaPartsHero

Go to autozone and get the code, you won't have to guess anymore

calvin924597

oh whoops, forgot to mention that i pulled the code using the paperclip method... comes up as the idle control system or P0505

97ej6dx

ahh IACV try checking for a freyed wire or you may need to clean out the IACV check to see if it has gunk in it. if its clean the it may be a bad connection to it. id suggest unpluggng it and make sure there is no corrosion and make sure the wires are pulling out of the plug.> i would try also to test the voltage going to the IACV and then try to see if you get power going thru it for ex if the IACV was bad it woulnt have power coming out of the ground side but if there is then its good.

97ej6dx

Hmm there is another guy having the same problem and he has a 99 and he said he has one on his car. (fast idle control valve)

calvin924597

yeah i have one too... cleaned it out with throttle body cleaner and it didnt seem to help. is it possible that the whole fast idle control thing is bad?

97ej6dx

did you tighten the spring up?? otherwise you may try to clean out the IACV and make sure your getting the fill 12 volts to it

97ej6dx

I drew up a diagram on the spring

Leland

Not to jack someone's thread, even though its old but i'm having the same issues with my b18c swap into my 99lx...it starts up and goes to like 4k, then will jump from 1-3k the whole time I drive unless under constant throttle...I've tried:
-3 different iacv's, all cleaned prior to installation
-obd1 p72, I have knock wired in, only code I'm pulling is vtec bc its not pinned in yet...
-pulled apart fast idle and it seemed bottomed out because it wouldn't move either way?
-re-routed vacuum lines over and over
-sprayed carb clean all over and couldn't get a response
-new im gasket/new tb gasket
-skunk 2 im
*I had to convert from 3 wire to 2 wire iacv, does anyone happen to know if I got the wires backwards on the plug, would it through a cel? I have it pinned correctly in the harness at the ecu, but i'm not sure on the plug because I didn't have the same colored wires for that plug and I could've gotten them mixed up...I've been reading and working on this thing an hour or two a day for a week trying to fix this!

blazzer

check your wires Leland, uber easy to mess those up, trace them back to the ecu if you have to. (i had to on mine -_-) not saying that will fix this but still need to check and confirm they are good.

if so are the wires soldered and connected properly?

did you open up your fitv and clean it? just because it is bottomed out does not mean it is all good. take it out and clean it.
here is how > https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/

r you say re-routed vacuum lines? did you change them around or just make sure they were not leaking?

did you bolt on the IM and TB to spec when you replaced the gaskets?

you did not mention, are you throwing a cel?