Picked up a 98 hatch with an ITR swap and having some issues with it not staying on.

When I turn the key, the car cranks and starts with low revs and then immediately shuts off. I can keep the car on if I keep steady on the gas pedal and rev it up, but as soon as I let go off the pedal, it shuts off.

Only​ thing i have done since last successful start is an oil change and only possible thing I can think of is that maybe I hit something when I was prying out the old oil filter that was glued on, but I've checked in the car and don't see nothing extremely out of place.

Have searched everywhere for answers, but nothing seems to solve the issue and I'm about out of ideas. Can anyone share some suggestions?

Here are 2 videos, the first is just turning the key with no gas and the second video is with keeping pressure on the gas pedal.

Video 1 no gas pedal - https://photos.app.goo.gl/qh41Kyg8aKS5tLsk7

Video 2 with gas pedal - https://photos.app.goo.gl/F4CA1hgJnhrJ9CUF7

Here is some things I've already tried:
- Replaced fuel pump (had to do it anyway, I am able to hear it turning on)
- Replaced MAP sensor with a new one from AutoZone
- Replaced IAC with a known working one from a buddy's car
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Any help is greatly appreciated!!
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did you try to keep the gas on until the engine get warm?

 

I came across that suggestion on my search but was hesitant to try since I couldn't find the reasoning behind it. I'm worried that it may cause some damage to the engine since I have no idea what's wrong. My mechanic skills are a bit limited so trying not to guess too much so I don't end up breaking something else. Does the car need to warm up to relearn to idle?

 

check to see if map and tps plugs are switched around and also check the tps voltage

 

Was able to get the car to stay on after holding rev steady for a little while, thanks for the suggestion @Brembomaster .

​​​​​Here is a video of it running without having to keep the revs up, any idea why it's running like this?

Video - https://photos.app.goo.gl/sTiTH1jY6631z1q4A

 

Possibly a bad IACV. The IACV helps hold the engine idle at cold starts and corrects the AFR until it reaches temp, a common sign when you hold the throttle down to keep the idle up during cold starts is a bad IACV, you can try simply cleaning it out with brake cleaner and install after it dries, I recently had this issue, when it would not start properly in the morning and I had to hold the throttle till it warmed up a bit, I cleaned it out and it starts right up and holds a high idle when I crank the engine over. Seems you replaced it already but are you sure it was a good working unit?

 

Have you ran any codes yet? I am leaning on the coolant temp sensor on your cylinder head if it runs properly when warmed up . That sensor will give you a code . The first sensor you see on the front. It might be pending.

 

The replacement IACV came from another 98 civic that is working with no issues, so we assume it's functioning as expected.

 

We haven't done this, but it's not running properly even after it warms up.

 

It almost sounds like a misfire. With the engine running, pull one injector plug at a time and if the engine sounds worst, replace that plug and try the next plug. If there's a misfire, you will pull a plug and there will be no change to the engine note.

Let us know what happened when you have done this.