Idle Issues - Page 2

Mikz86TA · #11 03-06-08

No miss tonight.
I do have headers with a AIR tube that I plugged off. I hope that isnt the problem. Just a cap on the end ot the drivers AIR tube fitting.
My miles are about 46K right now. I doubt internal motor issues.
Prob MAF or something with a vaccum leak or cap-rotor.
Def not TPS. It is smooth as I can tell. and its mostly idle and not throttle.

Mikz86TA · #12 03-06-08

So that damn clip finally uploaded.
Sorry at the end it gets a glare. But thats just the fuel trims. Which Ive read a little on and got the just of it. Short Term is what the PCM changes to compensate for the immediate needs and changes in fueling. Long Term is what the PCM uses in most situations but will change to adapt to the frequency of change in the Short Term.
If that sounds right, confirm.
If Im way off base or close, please correct me.

CLIP :
http://videos.streetfire.net/video/a...570034f31a.htm

enjoy the ambient music =) The camera mic apparently is very sensative.

nomaboy · #13 03-06-08

considering you just put headers on it i would bet you have burned a boot on one of your plug wires. happed to me....twice. it was intermittant and just noticeable to be annoying. i discovered it when i was in the drive thru at burger king. i could hear the arcing of the plug wire bouncing off the building.

hero dave · #14 03-06-08

my astro had 41k on it...it was only 1 1/2 old....they said it was maintance issue (cap rotor plugs and ect...iI know at 41k? what the hell?!) that is why I was working on it....they changed the engine after I did all that even thought I told them that wasn't the problem (cap rotor ect..).

Mikz86TA · #15 03-07-08

Ive realized today and tonight it only does it when its above poerating temp. Closed Loop.
I do have a quesionable plug wire.
Thinking that or somethig else

Mikz86TA · #16 03-07-08

OK.
Only does it after it warms up 180* +
Gets worse little by little over time afrter warm
Chugs a bit under load and light throttle
AirCond. on at idle is no good...it alsmost wants to die
Headers seem to be getting really hot cause I can smell the burning odor of the stainless. If youve had headers and a severe lean condition you know what I mean. Lean worries me alot. Lean and excessive heat is no good for the valves and cat.

In the past Ive had this other issue I could never figure out. Im cruising and come to a red light/etc. I push in the clutch and take it out of gear. Coast to a stop and brake. As I roll up to the stop, the RPMs go up a bit, back down to idle and back up than finally idle again. It self revs basically and usually 2xs and sometimes 3xs.
I can get a clip of it if needed. Its not a high rev, but noticable. Ive just learned to live with it but want to take care of it if possible. Does it in stock and JET tunes.
IAC motor, MAF, TPS or MAP are my 1st thoughts. TPS seems fine and smooth according to the analyzer and you can see that from my prior video clip on this thread. IAC I though of once cause it seemed to happen after I did a TB cleaning and shot a bit down that passage. But I dont remember if it did it right after that or not. Ive done a few TB cleanings since. Problem is still there. Could be bad, but it seems the PCM would have to tell the IAC to actuate to raise the idle. Should only do that in startup warmup and A/C being turned on. So what would tell the PCM to actuate the IAC and cause the revs? Anything else other than what I just mentioned? MAF readings seem fine. They only move as you see in the clip on throttle and a small amount when it misfired at idle. A new MAF is alot of money and not something I want to just 'try out' but will if someone thinks theres a problem there. MAP Im unsure about. Seems to be reading OK.
I know a malfunctioning MAF will cause a lean condition and Im almost sure its lean by the amount of heat off the headers and the smell I spoke of.
Something I noticed today when driving. With the analyzer on the O2 Bank 1 and 2 screens, Im driving in gear through the 'hood. In 2nd gear and 30MPH approx. Im on the throttle and the O2 readings are jumping around like they seem to do always. I let off the throttle and coast. O2 readings are still moving around and some go as low as 30mV as per the reading scale. At one point in the coast, the O2 readigs just drop competely to 0. Yes 0. Both of them. If I give it throttle, they jump back up. WTF is that?? Normal?? Isnt that no fuel? hahaha

Mikz86TA · #17 03-07-08

Swapped the old cap and rotor on it between the rains here. NOT the problem. It still waits until its at operating temp to start missing.
Going to put the Borg-Warner cap and rotor back on it sometime.

I unhooked the IAC just to see what happens. Dont do that! Apparently the 'rest' position for the IAC is wide open. It started and idles for a second and then the RPMs shot up and I had to kill it at 3K. Didnt like that at all.

I have 2 issues as you now read in my last post. One I can deal with and has been going on for quite some time and the miss problem I cant deal with.

Next Im going to unhook the MAF tonight while I drive it around. Im going to wait untill the idle rev issue pops up and then do it. That way maybe I can isolate the MAF as a cause on that. I may buy a new IAC too.

Im going to my storage to pick up my OEM coil and plug wires. They were good when I removed them and I want to use them to test for an issue. I bet its this one plugwire. It just seems weird it only does it after 180* / Operating Temp.