hey, well here is whats happening:

my car seems to have a problem. When i try to start my car, it starts slow sometimes, and somewhat normal other times. I believe this is due to low compression on my rear rotor due to a stuck apex seal. Now, after starting, as usual, it revs higher and then a little later it idles and stabilizes. However, my idle seems to stabilize around 1500 rpms, and after my car gets completely warmed up it moves to about 1200-1000 (this is all with the idle screw pretty much screwed in as far as can be). After my car is plenty warm, it seems to want to die, and the rpms go down to around 800-400 depending on how bad it does this, but right after doing this, it returns to the original idle of 1200-1000 rpms and it does this off and on but it will take a short while before it does this again. On top of this, the car seems to misfire and makes a popcorn popping sound, but the pops don't follow a rhythm, so they are kinda unpredictable. The popping noise occurs from what i can tell, at all rpm levels as long as the rpms are kept in one spot (i cant tell when im reving it). What is weird though, is that even with the combination of these two problems, in between their occurrences (the popping is always here and there, but it doesn't want to die until it is like at normal temp) the idle seems to run smoothly and sounds niice. I DO have a small vacuum leak under my upper intake manifold also.

Today i checked my timing today, and i noticed that whenever my car wanted to die my engine kinda jerked and the timing light would hesitate for a sec then would return to normal, (is this to be expected from what my engine is doing?)

also when checking the trailing timing it seemed to pulse slower than the leading one did is this normal?

do you guys have any info that could help me out? or do you need more info on anything? (im thinking about making a video so people can see what i mean, so if you think that would help alot i'd be glad to get it done asap)

man, i'd really like to drive my car :/ (yeah i just bought not too long ago)

 

I would get that intake leak handled, it can cause a lot of problems, especially for your idle.

I would imagine the change you see in the timing light is simply your computer trying to adjust your timing and keep the engine running.

If this will be the first time you have the intake off I would also recommend checking out your other vacuum lines, they go through a lot of heat cycles and tend to crack.

 

your leak is the problem.. get that fixed asap if you want smooth idle.. but if what you said is true your damaged rear rotor will cause an idle that sounds like its been ported but the idle will not fluctuate.

 

edit : oh wait, low compression...

 

yep, low compression will cause it to idle like a ported engine too

 

alright, well i'll look into fixing that vacuum leak asap, then i'll see what happens next!

 

well, i replaced my all my vacuum lines with silicon ones. i started it back up and it ran PERFECTLY. it goes to 3000, then drops slowly to 1500 and idles. then i took it on a small drive and when i revved it high one of the hoses on my intake funnel (i have 2 plugged in from the bottom) popped out and it died, so im like ok i plug it back it and i walk off. Well, later i put on my s5 actuators and took off my sub zero startup valve because i spotted a unhooked hose that i forgot to replace, and had to plug it into a nipple that i had marked with the same letter (the only way to get to it was to take off the valve). then i reinstalled the sub zero startup valve. The next day i start up my car and it goes to 3000, comes down to 1500 and then STAYS THERE . i check my a/f ratio and it says 21.0!!! and fluctuates give or take 1.0. it also started doing that surging idle a little bit. im freaking clueless. what could be wrong???

oh by the way, my a/f ratio says my car is running lean right? but i checked my plugs and they are blackish so its running rich?? O.O