Trouble starting and high idle then fluctuations

[Apex3]

I have this problem that's been bothering me, I figure I should probably figure it out so when I install my remote start I don't look like a jackass but also because I probably shouldn't ignore it anymore.

Basically what happens is, it takes a little while to get it to start, it'll always do it on the first try, but usually takes 6-8 cranks or so to start when it's cold. Once it's started though I can turn it off and it'll start on the first crank, I can leave it for 20 minutes or so and it'll still start right away.

Once it does start, it idles high, around 1800 or so, until it's a little bit warmed up, tapping the throttle will drop it a bit, AC on or off effects it too. After the car is warmed up completely it idles in the right spot but it'll go up and down by +/- 100rpm or so, but only at a complete stop, as long as I'm rolling at all it idles just fine.

Normally I just replace things until it's gone but I'm not really made of money anymore so I probably shouldn't. It could potentially be more than one thing, as I had a vacuum leak before that was making it worse, and it's done this since I bought it. I don't think I have a vacuum leak anymore, I seafoamed it and there wasn't any sign of a leak, but I'm not gonna rule it out.

Any ideas of what to check? My ideas for potential culprits are as follows
-O2 sensor(the one on it now has some glue over the wires where it attaches to the sensor, wtf? Also I unplugged it and there was no change whatsoever in how it ran)
-Coolant temp sensor(The fan seems to work normally though, so I'm not sure)
-ICV or maybe the idle adjustment screw, I'm hesitant to mess with the screw though
-MAF sensor

Thoughts?

[Legacy777]

Any idea how old the coolant temp sensor is? With engine temperature related issues, it's something that is relatively inexpensive to replace, around $20

[Apex3]

Any idea how old the coolant temp sensor is? With engine temperature related issues, it's something that is relatively inexpensive to replace, around $20

Haven't a clue, and I was kinda thinking that, but would the fan be on all the time? Or not necessarily?

[Legacy777]

Not necessarily. When the coolant temp sensors fail/wear out, they can produce very odd running issues.

[Apex3]

Not necessarily. When the coolant temp sensors fail/wear out, they can produce very odd running issues.

Cool, maybe I'll go do that right now while it's nice out

[Apex3]

Still the same when it's warmed up, I'll chime in tomorrow when I find out if it's the same when it's cold still.

[Apex3]

Yea, the sensor didn't change anything, warm or cold.

[Legacy777]

Any idea what your fuel pressure is doing? When's the last time you replaced the fuel filter?

[Apex3]

Any idea what your fuel pressure is doing? When's the last time you replaced the fuel filter?

I don't know how to check without a gauge, so no. Replaced the filter a few months back, it didn't make any difference. I was thinking of checking the fuel pump when I got home this weekend.

[Legacy777]

Yeah....I'd try putting a gauge to check fuel pressure.

[Apex3]

Well, since I won't have access to a gauge here and forgot to check when I was home, I'll ask another question

The fuel pump is kind of loud when I first start the car sometimes, didn't realize it was making the noise I was hearing until I took out the back seat, but sometimes it whines for a few seconds when I first start, is that normal? It also seems to be pretty loud with the seat out but I expect it to make some noise. I'm also looking at my upside down rear seat propped up on my wall and noticing a slightly melted spot in the foam right above the fuel pump.

Also of note, my speedo is laggy, it works, but it takes a bit to catch up sometimes, like I'll speed up and let off and it won't actually register a speed until after I've let off. I noticed you mentioned the ecu recieves a signal from the speedo so maybe this is a possibility?

[Legacy777]

The pump will prime itself on key in the "ON" position. Take a look at the fuel pump connector and see if it is burnt/charred. It's unfortunately common for the wiring to be loose and cause excess heat at that connection. You can remove the pins and use insulated connector replace the stock connector.

You can try pulling the speedo cable out and regreasing it. There may be old grease caked in the casing which may be causing it to bind and react slowly.

[Apex3]

Okay well I've been busy(and lazy) and haven't got around to checking this stuff while I've been home, but I turned on my car today and the exhaust smelled like sulfur, but it went away after I drove, sign of a bad cat or normal?

[Legacy777]

I wouldn't say it's normal....but I don't know if you can conclusively say it's a bad cat...