what would cause this?
 

when i started my car up yesterday the rpm went down to about 50- 100 rpm and sounded like it was about to stall. After about 2 seconds the rpm shot back up and the car ran fine. Also sometimes when i start my car when it is cold it makes a sortof tapping sound right on the start for about 3 seconds and then its fine. What could cause both of these symptoms?

any mods???

vacum leak for idele.

rocker low oil lifter where the noise coming from ???

I can't tell exactly where its coming from. Its kinda tricky, sometimes i think its coming from under the car like in the exaust somewhere. Sometimes i think its the engine making the noise. I'm just gonna get a new x pipe put on and see if that helps it, if not i'll have the engine inspected and possibly rebuilt as i'm planning on getting a super charger and i don't want to blow the thing up.

what kind of mods do you have?

Is it a bad throw-out bearing, flywheel, engine low on oil?

its an automatic with only bolt-on mods like hedders, dynomax super turbo mufflers, mac cold air induction,and 14 degree timing. I think thats about all the mods as far as the engine goes.

Get a stethoscope, like the doctor's use. Except get a mechanics stethoscope. This will help you out a lot when looking for things like this.

I had an 87 ranger 4x4 and it was making this ticking sound, but I couldn't tell exactly where it was coming from. I got a scope and stuck the pointer on the right vavle cover. Damn, that was loud. Turned out it was a stuck lifter.

Hope this helps.

You think so? i hope its something that simple but i'll check it out anyway just for peace of mind.