Idle issue beyond IACV & FITV

[mjsstanley]

So beyond my heating & cooling issues (which is still a nightmare), I'm having an idle issue. The last repair I had done was changing the IACV & FITV. After that, the car still idles high. So today, I had my radiator and thermostat changed for the third time. When I first drove the car, it literally would not accelerate. It bogged down horribly and idle went up and down. So I pulled over and unplugged the plug that goes into a triangular piece on the back of the throttle body. After doing that, car drives just fine, however the idle is at about 1800rpm and of course CEL on. Anyone know what the fix could be? What's the black triangular piece on the backside of the TB?

[4GAccordH22]

That is the throttle position sensor. Plug it back in and find your issue. This is most likely not it. You may have a vacuum leak somewhere or an air bubble in the cooling system.

[Fleetw00d]

Did you replace the IACV and FITV with new parts or used parts? Have you (or anyone else) messed with the idle screw on the throttle body? Did it ever idle correctly at about 750 rpm?

[mjsstanley]

If I plug that back in, the car will hardly move (idle jumps up and down). It acts like something is clogged into the muffler. Unplugged, the car drives just fine, however idle is high.

The parts were replaced used. The mechanic cleaned them with carb cleaner and also made sure the o rings where not broken. And yes, at one point the car idled just fine exactly at 1k rpm with the sensor unplugged.

[Fleetw00d]

For good measure, you need to install a new IACV seal and replace at least the o-ring on the yellow piston in the FITV. It may look intact, but it has probably taken a "set" such that it no longer really seals. I just fixed the jumping idle on my 93 SE using a #23 o-ring from ACE Hardware on the piston and a #29 o-ring for the cover. When you install the piston, use a little lubricant on the o-ring and the inside of the valve to help is slide. Run the piston all the way down, back it out one turn, then install the cover with a new o-ring. Use new seals between the valve and the plenum.

[EsperHamid]

So beyond my heating & cooling issues (which is still a nightmare), I'm having an idle issue. The last repair I had done was changing the IACV & FITV. After that, the car still idles high. So today, I had my radiator and thermostat changed for the third time. When I first drove the car, it literally would not accelerate. It bogged down horribly and idle went up and down. So I pulled over and unplugged the plug that goes into a triangular piece on the back of the throttle body. After doing that, car drives just fine, however the idle is at about 1800rpm and of course CEL on. Anyone know what the fix could be? What's the black triangular piece on the backside of the TB?

2 symptoms can lead to high idle. Your brakebooster hose or PCV hose or airduct ...

[masospaghetti]

If I plug that back in, the car will hardly move (idle jumps up and down). It acts like something is clogged into the muffler. Unplugged, the car drives just fine, however idle is high.

The parts were replaced used. The mechanic cleaned them with carb cleaner and also made sure the o rings where not broken. And yes, at one point the car idled just fine exactly at 1k rpm with the sensor unplugged.

You might have a bad TPS, but cleaning the FITV and IAV with carb cleaner hardly means they are functioning properly. The FITV in particular needs new o-rings and to be properly adjusted.

[mjsstanley]

Figured out what the problem was guys. There was some sort of screw that was too loose on the backside of the TB/IM?? I took it by a performance shop and the guy took an extended screw driver and tightened it up and idle went right down.

Now back to my cooling/heating issue

[Fleetw00d]

Figured out what the problem was guys. There was some sort of screw that was too loose on the backside of the TB/IM?? I took it by a performance shop and the guy took an extended screw driver and tightened it up and idle went right down.

Now back to my cooling/heating issue

Toward the back at the top (under the vacuum hoses)? Large screw about 3/8 diameter? About the only screw that would affect that is the idle adjustment screw. If he had to adjust it a lot, that may indicate that someone else messed with it and removed the RTV that was put over the exposed end at the factory to keep people from messing with it (and to prevent it from moving on its own). You might put a dab of RTV on it to keep it from moving again.

I'll have to take a look at your cooling/heating thread.

[mjsstanley]

Yes I'm sure it's been tampered with during one of my "cooling/heating" repairs. Going to post on that thread with the latest update now.

[EsperHamid]

it can temper itself by going over a bump, so put rtv as Fleetwood said, make sure to remove all vaccum hoses so you can be comfortable and give RTV time to cure before driving your car again. Good luck