BigJustinZ28

would a count of 0 at idle in park be considered normal with a hotcam ??? anyone know ???

Fastbird93

Ok, maybe I was misunderstood. I meant at normal operating temps, when driving, sometimes when I push in the clutch pedal and go to neutral, the RPM's will hang at 1500 or so, and if I give it a quick blip then they'll drop down to normal.

Hotwire

no, that's not normal, sounds like you have a vacuum leak somewhere. you want to get the counts around 160, that's ABOUT halfway between 0-255, but not center point. What's your map and maf reading at idle?

0 means the computer has your iac fully closed, that should pretty much stop all the air coming into the motor and kill it. see if your throttle blades are open, check for slack in the throttle cable if there is,and if they are still open w/ slack, you may have to adjust the throttle stop for the blades.

Hotwire

yes, the pcm has the iac following the throttle, so that if a quick throttle transition did happen, the motor wouldn't stall. if you look in your owner's manual, they will say while braking to ride the gear you are in down to about 1500 rpm or so, then push in the clutch and let it out of gear, this will give the iac sufficient time to adjust and let the car idle normal. same thing was happening to my 97 s-10 w/ 4.3 5 speed till i was bored and reading through the manual and found that. I also found the IAC Follower table in LT1 Edit.

good luck.

BigJustinZ28

at idle in park around 1200 - 1250 rpm (its set for 850 in drive)
map 45-46 kpa
baro 104 kpa (im at sealevel )
maf 16.4-16.9 g/s
IAC Counts 0

also scanned for codes , got a 141 (think thats sensor 1 banks 1 heater circuit) , 430 (bank 2 inefficiency) , and a 507 (I think thats idle system high IAC responding) Ive looked them up before.

I did notice the longer I was in the car at idle the rpm slowly started dropping it was around 1190 when I finally got out. I was scanning all this with the hypertech that doesnt work , only the scanner cartridge works (came with the car , im guessing he used it to up the idle to 850 at one time).

Hotwire

sounds like you got a leak. it may be sealing up as the engine gets warmer, might explain the lower rpms as you were sitting.

I can set my idle to whatever and the pcm will hit it, but then it starts loading up, about dies, goes closed loop, idles fine, goes open, and starts the cycle over.

my readings are:

at idle in park around 675-775 rpm (its set for 750)
map 47-77 kpa (stays 60-75, should be 40-50 stock)
baro 98.9 kpa (im not )
maf 9.5-10.5 g/s (should be around 5-6 g/s stock)
IAC Counts 90-100

so I feel I have some air going through the valves that shouldn't.

BigJustinZ28

you map probably varies more because I imagine at 750 you have quite a bit more lope than I do . I wish I could find the leak , ive looked for it but still no luck. Sometimes I wonder if the hypertech is just messed up lol. I wonder if I lowered my idle If my car would act more normal. My car burns more gas idleing than it does moving just about lol.

Wild1

That is interesting about the IAC... how do you clean and oil it. Can you keep the TB on the car and service the IAC or is that a TB removal.

Hotwire

pulling the iac w/ the tb still attached i think requires a special skill and some new words, I think it has been done, might want to do a search for it to find out for sure.

it's two torx screws, then it should come right out, grab some carb/choke cleaner and spray away. do not try and push in on the iac motor or twist it, get it clean, and the iac port in the tb, then glob some motor oil on the iac, inside the port, and on the o-ring around the iac. reinstall everything and you should be good to go.

good luck.

BigJustinZ28

is the motor oil essential ??? When I took mine out I just cleaned it throttle plate cleaner and reinstalled it (I took the t/b out and cleaned it too) .

Hotwire

yeah, the iac does need to have some oil on it otherwise it will rust and start binding. you could pull the rubber elbow, and shoot some deep creep or something in the iac port that is located between the throttle bores in the bottom of the tb. deep creep is like wd-40, but lasts longer and is made by seafoam, like high tech marvel mystery oil, it kicks ***.

BigJustinZ28

got your email and responded , it ended up in my junkmail folder cuz of the !!!'s in the subject hehe. I dont have the IAC port in my aftermarket t/b (contemplating adding it tho) so I might as well just take it off and oil it again lol. Too wet now tho , its been raining down here. Is there any other way to get oil down there ???
thanks , you are a great help , J

Hotwire

if you pull the rubber elbow, look at the space between the throttle bores (blades), you will see a hole that turns down towards the iac. it's sort of recessed back in the throttle body. If you look at mine, you'll see it outright on the BBK throttle body.
BIG PIC, DIAL UP WARNING!!
http://www.hpphoto.com/servlet/LinkP...2ab37249&size=

just shoot some down in the hole and you should be alright for the time being till you can get it back apart to oil it better.

suprchrged400

I am having the EXACT same trouble with my bored stock TB(52MM). It hangs up and if you kick it down, it returns to the stop screw. If the car is off, doesn't bind, on and running, it binds. I don't get it. I've tried to file out the holes on TPS and it makes no difference unless turn it the wrong way, then it idles even higher but can't get it to stay idling normal. I didn't think you could adjust the plunger since it's computer controlled- I did oil it and that didn't help solve problem either. ARRGGGHHH, Please help. Has ANYONE had this sticking throttle and actually fixed it????

93ZM6Tally

Interesting info. I have a 58mm BBK and don't really have any idle problems. I'm running a 227/233 CM cam too. Car idles fine. The only time I've ever had idle problems was when the Opti was on it's way out.