Hi everyone, I’ve been reading up some on this issue but can’t seem to figure it out. When I start the car cold, it idles like normal, however when it warms up, it sounds like it bogs some. When I drive it, under load it’s fine, then when I let off the gas, the rpm drops really low (350-400) and almost dies. Then it will come back upto about 650-700 and run but it still sounds like it has a heavier cam in it.
Ive checked timing multiple times, it is fine. I’ve replaced plugs. The plug wires and dizzy came off of a running normal Integra. I pulled the o2 sensor connector off and nothing happened. Then I took the TPS off and it started running really crappy...Rev up, almost die, Rev up, almost die, etc. also occasionally if I hold the rpm steady, after about 30-40 seconds, the motor just bogs down like it wants to die again, even while holding throttle constant. Does anyone have any information as to what the problem is? It has done this in 2 different cars (with different wiring harnesses).

Update: I can drive the car around fine. It rough idles at stops like it wants to die (got slightly better, added some coolant). I’ve sprayed with starter fluid everywhere I can in the engine bay, have gotten no results. If I hold the rpm constant at say 2500, it will hold there for a bit, and then it’s like I’m trying to run on 2 cylinders. If I let off the gas and immediately back on, it’s okay and will idle on its own. As soon as I hold the rpm constant, it will hold for a few second and then start to cut out again.

Video of what I'm talking about.
Note: I hold throttle at 3k rpm and never lift my foot till I blip it at 1:16

I’ve tried cleaning that iacv as well as used an iacv from another running motor. Haven’t had luck with either. I can try and new one I suppose. Car doesn’t have an FITV (99 Motor). Would the o2 sensor create this issue if it was bad/faulty? I unplugged it yesterday and there was zero change as to how it was running.
is there a good way to multimeter it or something to see if it’s bad? Or would it not cause the issue either way?

I changed the TPS with another stock TPS from a running motor and nothing changed. I pulled the TPS with car idling and it drastically changed the idle to a much more sparatic idle

UPDATES!!

i found a small vacuum leak between intake manifold and head. Rtv fixer that...sprayed brake parts cleaner around entire thing and didn’t hear or see anything more. Idle is still almost 2k rpm on cold startup then slowly makes its way down to about 700-750 but still sounds like it’s missing occasionally. Runs fine then will sputter a bit.

Did compression test: all about 140. So good there.
Took the short ram intake off and it sounds like it’s pulling air from inside.
I plugged the bottom hole inside throttle body with finger, no change at all.
Plugged the top hole inside throttle body, and it killed the car. I read somewhere that that means bad IACV??

all help is greatly appreciated. I feel like I’m close since I’ve been narrowing down

thanks again everyone!
- Matt

UPDATE:

picked up an IACV from the local U-Pull, changed it. Definitely a difference in motor, had to retime the ignition. Now idle sounds good and not like it’s missing, however it idles super low now, like 450-mayybeee 500 RPM. Anyone have ideas as to why?

I reset ECU and still does it.

I ordered an IACV from a 98 Integra LS 5 speed.
Just curious still, what would be the difference between IACV’s?

Thanks for all of the help.
- Matt