Okay... I got my car running after breakin the **** out of my rod journals and rod bearings and after changing the crankshaft and bearings my car runs pretty good. Couple days after I start seeing symptoms of something. I don't know what's wrong with my car.

Symptom: When holding the car at 2k, with the same amount of gas used to hold a steady rpm, the rpm gauge gradually goes down... Why is that? And after dropping a good 500 rpm, it fluctuates and bounces around 1600rpm - 1750rpm. (Keep in mind, I haven't changed the amount of gas I pressed to originally to get the rpm at 2k). Do you think the possible cause can be:

a) ignition (timing/distributor)
b) vaccum (hoses)
c) o2 sensor?

If possible provide advise/words of wisdom through experience! Thanks once again guys.

 

to me.. personaly.. it sounds like sumthing the o2 sensor would do. if u had a vacum leak. ur car would fluctuate at idle even without pressing the gas. unless ur car does it at idle as well. then it would be a vacum leak.

 

well, its normal for it to drop a liiiiiiiittle bit cuz when the car is idleing it is usually assisted by the iacv, so when you rev it up and hold the pedal it will drop slightly when the iacv is no longer assisting, but probably not as much as yours is dropping, so yeah, id check for leaks and o2 sensor, also you mighta effed up your tps....and one last but not least good possiblity, have you bled your cooling system, cuz obviously your cooling system was drained recently

 

Bleed my cooling system? Since when does that interfere and cause rpms to fluctuate?

A good thing that you pointed out could be my tps sensor... The thing is... my ecu isn't throwing out any codes... which is weird.

Question of curiosity: Could it also be (since my car is miss firing a lot) that I need to ajust my valves? (Lash)

 

the valves usually won't make your idle fluctuate, it will just make it either idle right or shitty... Having air in your cooling system will definately make your idle fluctuate, when the air goes thru ure IACV it will cause the rpms to go nuts... So that is a good possibility...

As for the TPS, prode the middle wire and have somebody slowly depress the throttle, the voltage should go from about .45 at closed to about 5 at WOT

 

Is there any way to test if my o2 sensor is still good?

 

yea i forget the specs but if u search you can find em

 

I'll try searching to my best abilities. But excuse me if I fail =P I'm tired of this rpm disability... cuz when I push my car... I'm sooo much slower... and I don't feel like slapping my zc cam on my car yet with this problem (d16a6 engine)

 

Okay. So I should flush my radiator? How do I completely flush the whole cooling system?

Because all I know... My car... is suffering in its power band tramendously due to this rpm act-up. And before i changed my crank and before the bearing went out, there was nothing wrong with the idle/rpm range.

So yea, if anyone could tell me where and how to completely flush my cooling system while depleting the air which is throwing my rpm off, I would be forever greatful! Thankyou!!!

 

you don't need to drain the system, unless you want to... where the upper rad hose comes out of the head, you should have a little bleeder screw on the water neck, it looks like a little volcano shaped bolt, just unscrew that slightly, then start your car and let it run until coolant begins to come out, then tighten it back down, then you can let your car cool down and do it again if you wish, but thats about it

 

Thankyou so much nappy. I'll get back to you after I do so. Hopefully that solves everything. Wish me luck.

 

Well, I bled my cooling system. No luck there. =/ Next is the o2 sensor... =/ and then test the tps sensor. But I don't its the tps sensor... because I remember when I had a bad one when I would rev the car.... it would rev, then drop straight down like it was going to die to idle, then kick right back up then gradually go down to idle... So i hope its just the o2 sensor... ugh...