I have a 90 Integra RS. For the last month is has been having all kinds of idle issues.

So far I have replaced:
Hoses on IACV
TPS
O2 sensor (wire snapped on mine)
Cleaned the throttle body
Cleaned the IACV
Flushed the coolant system

My car still has issues. Every time I push my clutch in to shift between 1-2 2-3 etc it revs up higher for a few seconds until it slowly starts to drop. Basically its like not taking your foot off the gas when you shift.

Also I unplugged the IACV and it ran good, just idled like a cammed car during cold start but after that it idled great and ran great.....except it seemed like I was burning more fuel and I could smell fuel. I figured its the IACV but someone said if you unplug it nothing should change if its bad but when I unplug mine everything changes.

I have fixed all my own cars for over 10 years without any issues but this is my first obd0 one and I am stumped. I checked the entire vacuum system and no leaks.

If you have have this same issue and have fixed the problem please help me out.

Please dont just tell me guesses and your idea unless you definitely understand the issue because I no longer want to through un-needed parts at this car anymore.

 

I KNOW ITS FRUSTRATING! GOOD LUCK WITH IT!

 

Its very frustrating but thank you I hope someone has an idea what it is

 

Is the car running rich by chance?(check plugs) ? reminds me of an idle issue my gsr gave me by staying in open loop for too long/dumping too much fuel on start up. 2nd did you calibrate the TPS when you installed it. 3rd did you bleed the coolant system after you flushed it. when it's first starting up does the engine shake(may not if you have aftermarket mounts) ?

 

I dont understand you said when u unplugged the iacv it ran good wouldnt that be your problem. If it runs good with it unplugged but horrible when plugged in then that is a problem correct. For me and what your describing i would personally try another iacv because that controls your idle speed with no load....hence when you depress the clutch it goes to no load and iacv takes over....that is when your describing your surge in yhe idle

 

If anyone chimes in on this I just though about the fast idle being an issue maybe.....any input would be helpful

 

Yeah that is what I figured to but then someone said if your iacv was bad, when I unplug it there should be no change in my idle......is this true

 

Bled coolant system, checked spark plugs cause the car was running rich due to no o2 sensor, and I calibrated the new tps. With IACV plugged in car never drops revs during shifting and idles really high. When its unplugged it idles great and runs great after warm up, but during warm up if bounces between 1500rpm and 1700rpm once warmed up it stops...so could that be the FITV?

 

could be if it does it primarily on start up, clean it and see.

 

how do you go about cleaning the FITV???

 

https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/

 

thank you. I just found a complete write up on idling issues. Thanks for all info

 

I HAD this same issue on my '90 DA. Did you fix your problem?

 

okay so I fixed the idle problem now Im having another one.

My car keeps stalling out when I down shift or let off the gas, it seems to lose fuel pressure. I stopped on an incline and it stalled and would not start until I got it back to being level.

Things I replaced:
distributor (cap and rotor also)
spark plugs
plug wires
fuel filter
fuel pump
full vaccum check

I still have the same issue. It will idle perfectly but once I start driving it will stall out, and when i start it is sounds like a subaru for about 10 secs until it idles out. Its like it is flooding itself when driving but when on an incline it loses all fuel pressure.

Any help would be great

 

get a fuel pressure gauge and see what it is at idle and when you rev it. any CEL ?

 

Could this possibly be a bad Engine Coolant Temp (ECT) Sensor? This can cause similar issues because the sensor is telling the vehicle it needs more gas. The vehicle would normally smell very rich and it could cause flooding... I had a similar problem and this was found to be faulty and fixed my issue.

 

I just got off the phone with the shop and he found out that a sensor in the tank on my sending unit was bad so he replaced that and it fixed one issue. Now he is replacing the fpr because it keeps fluctuating fuel pressure at idle

 

coolent temp sensor is testing okay but thanks for the info for future reference

 

and no check engine codes coming up. The CEL light does not work due to previous owner removing the bulb.....some people are just scum lol

 

Curious how did you calibrate the tps.

 

The Official Honda TPS wiring and calibration thread

https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/official-honda-tps-wiring-calibration-thread-2830131/

 

Did the new fpr fix the fluctuation at idle ....curious to know when there was the fluctuation in fuel pressure at idle was your idle speed constant or also moving up and down?