Devon_Arden

so i have recently aquired a b16a in a 95 hatchback civic... the car runs great ..no smoke ...never dies ...when its cold i start car ..it runs fine ...by the time its warmed up and im on my way to to work...when at a light sitting idleing the car surges ..rpm from the low idle up to just under 2000rpm just up and down up and down...never surges when driving ..only when clutch is in ,..and im at idle. it has fast throttle response ..it pulls hard... evey thing else is good .... the odd part is ...when i unplug my throttle position sensor the idle problem is gone...it immediately smooths right out ..a bit on the high end of a idle but smooth none the less....you drive car with it unplugged and you wouldnt know anything was wrong ...plug it back in ...and she jumps up and down right away....my frined had a d16 vtec sittin on his bench so for ***** and giggles i grabbed his tps ..bolted it up ...no different ...idle still surges ... please help!

ThE HeLLRaZoR

No CELs?

Devon_Arden

i gotta find the plug in point on the car to check the engine light becuz it is on yes...but with the swap they did before i got it ...who knows if it always be on..i will have a look around a bit more tomorrow and see if i can find it ..read them ..clear them...and see what ones return
any idea as to why when i disconnect the tps it runs better...?

zap

tuned ECU? maybe the tuner forgot to tune your idle columns. thats why your idle is jumping everywhere when your vacuum changes.

Devon_Arden

dont believe it is tuned its on p30 obd1 the guy i bought it from is convinced it is the o2 sensor ..i got a 2.5 half year old girl ..daycare full time job and a few other things that take up 95% of each day ...i know hes got the exhaust done...perhaps he has eliminated a o2 sensor from the exhaust system and the ecu is trying to figure it out?>?

OneBadTurboCRV

You need to figure out the code first.

https://honda-tech.com/honda-civic-d...lists-1901557/

Once you do, then your issue can be narrowed down. You could have plugs in wrongs spots, IACV issues, wiring issues, etc... Many things could be wrong. Get the codes first, it doesn't take but 5 minutes out of your spare 72 minutes you have each day.

testify

It's your Idle Air Control Valve.

hondacivic97si

Not a huge expert, but Im pretty sure Testify is correct. You need to clean your Idle Air Control Valve and, if your car has one, the Fast Idle Thermo Valve.

Devon_Arden

UPDATE : i have turned my idle down with the idle screw..brought the idle from about 1100-1200 down to bout 900 ..and it has improved the stability of the idle alot ..it still does it ..about 300 rpm up and back down ..but it corrects itself after a few seconds of doing it ...and idles at 850-900 ..the problem is still there but not as bad ...what would be the best way to clean the iacv ?? seen a few way .. and my Fast Idle Thermo Valve is the one with the lil plate on it held by 2 8mm bolts ...has a large pin in the middle that moves in and out with a plasic ring around it correct? if that is the one you refer to ..i popped the door off of it ..and i made sure the platic ring was done up tight and proper and made sure the pin was free moving in and out it appeared to be clean and easily moved in and out ...ALTHO the plastic ring that you are to tighten down i could not get to move ...it was done up tight ..wether it is done up so tight i couldnt move it or it is stuck ...but watching videos from eric the car guy on youtube ..he says that the plastic ring should be done up snug as she goes ..not super tight just snug ...mine is way more than snug ..someone has definitely seated it good ..its in a incredibly difficult spot to work comfortably while leaving you manifold on

Devon_Arden

ps ..i am gettin a list of codes and pulling cel this weekend

holmesnmanny

The problem is that you have a vacuum leak.

The new problem is that you screwed with your base idle.

Find and fix your vacuum leak, then adjust your bsse idle back to stock again.

hondacivic97si

You have to look at the FITV and see how it works as a valve. There should be an intake and an exit that lets air bypass the throttle plate. Make sure the plastic ring isn't stuck in the wrong position, and that it can let air trough.

I cleaned my IACV by removing the entire throttle body (on which it was mounted). Only way I could reach the screws properly. Some say not to do this because it may screw with the Throttle Position Sensor. Also, your IACV may not be mounted on your TB so find the best way to take it off.

You clean it with carb cleaner. I also gave it a dash of WD40 specialist silicone to lubricate it, but that might be overkill.

You can use the carb clean to check for vacuum leaks too.