JDMswagSerf

Hello I come for help!
I have a 94 Acura Ls coupe.
It is Auto trans, stock besides air filter.
The car has a bad idle.
I start the car, and the idle is normal (as it is when it's cold start) for 3 seconds then the idle bounces from about 1500-2000 rpm.
It continues even when car is warmed up.
It only does it in park and neutral. All other gears, the rpm drops to normal.
NO CEL
What I've done so far

Bleed the cooling system numerous times.
Clean iacv
Remove components of fitv and thoroughly clean.
clean shift trans shift solenoids(cuz it did it in park& it drive, worth a try)
Remove tps, and adjust it to .50v idle, 4.50v wot
I've checked all vacuum lines, pcv, brake booster, evap,& fpr by removing the line and plugging the intake vacuum port with my finger, still surges.
Note: the pcv hose from the intake is not plugged into the pcv box, it is plugged up, don't think the pcv box venting to open air would cause this though.

I think it is a sensor related issues but idk which one?!
When I disconnect a single sensor this is what happens
Disconnect:
Iat, nothing happens
Map, idle drops for 3 seconds then continues to surge
Iacv, idle rapidly surges +or- 50 rpms
Tps, idle drops to normal.

I don't think it's a vacuum leak because wouldn't the surge continue all the time even in drive or even when the tps is disconnected?
Or if it is a vacuum leak, only things I can think of, cracked manifold, or bad TB or Intake gasket.
Any ideas what's causing this?
THANKS IN ADVANCE!

JDMswagSerf

??

I am going to replace sensors with known good ones.

JDMswagSerf

,

JDMswagSerf

Update
Cleaned the iat/maf sensor.
Did a smoke a test. Fixed 2 leaks.
Swapped a good ecu.
Re calibrated tps
Put known good iacv in.
Still surges
If iacv or tps is disconnected. Car stops surging.
I know the iacv is good cuz it was working when I took it off my other car
Going to swap the tps even though its been re calibrated and has no cel.

Eg.ls.turbo

Did u mix the iacv plug with a different plug? What color wires is ur iacv plug

JDMswagSerf

I don't think so.
I know the wires on the iacv are the shorter wore rather than the longer wires which go to the evap solenoid.
Iirc the wires are blue in yellow.
But definitely the shorter pair of wires go into the Iacv.
Not the longer ones
I am suspecting the tps is just wack. Even after re calibration and with no cel for it.
Cuz know good ecu and iacv are on the car. The idle still surges regardless the iat or maf sensor are in. No leaks. And when tps is removed. Cat doesn't surge. Putting a known good tps on tomorrow and gonna mess with fitv screw

JDMswagSerf

Swapped the maf and iat sensors with good ones. Still nothing changed.
Cleaned all ignition parts. The idle was normal for about 15 seconds then started bouncing. About to change tb and tps with a good one! Brb.
I am so close. I can feel it

JDMswagSerf

If anyone ever comes across this!
I finally have a steady idle.
I changed the tb gasket. Cleaned the hell out of the tb, put a good tps sensor on and screwed the fitv in almost all the way!
It is 1 turn before its on all the way.
Maybe the tps and gasket were causing the bad idle too.
But I got it fixed!
Idk how that valve even got un screwed.

For future viewers, check this link!
https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/

Thanks to everyoneeee that viewed this lol

cushnerjeff

I had same problem when but my b20 in teggy it was a leak in my intake mani and throttle body make sure u have novacume leaks and the iacv was also a problem once I gogt the rev problem figure I have the Neptune demon and I had to go into the ecu and put my iacv down to bout 5 percent and it stoppd so it could be either thing

91 acuraDREAM

ive been having the same problem exactly in my 91 integra with a b18a1 ive replaced map tps o2 sensors cleaned fitcv and the iacv gonna go through and replace all gaskets re clean and tune everything i any advice

billabongrob

iTrader: (1)

When checking for leaks at your gaskets, I would recommend shooting carb cleaner, or equivalent, around them. My idle surged very bad until I started doing this and was able to pinpoint leaky o-rings on the injectors and then the Intake Manifold gasket. Helps pinpoint these issues much quicker in my opinion.