Ahhh im stumped [CEL p0505]

[justinhill98gst]

So i had the cel light come on after i redid the throttle body gasket (yes i disconected the battery) witch was code p0505 witch is idle control malfuction, I did do some searching and tryed to see what other people did so i bought a new icm and disconected the battery and put in the new idle control motor and this what i get it still stumbles after 5000rpm and now it will give a little buck so i was like WTF ? it is still throwing p0505 to the ecu any other ideas what i can do? by the way its a 2g gst 1998

 

[turbosax2]

Do a boost leak test.

 

[tunerguy08]

Have you tried a maf test or a map test?

 

[kenamond]

How does it idle? If you have a boost gauge, what is your idle vaccuum? And did you do a boost leak test after you "fixed" the boost leak at the TB gasket? If so, how much pressure? How long did it take to drop 1psi after you stopped adding air.

 

[justinhill98gst]

No i didnt not do a boost leak test yet, The idle keeps surging up to 1500rpm the drops then jumps back up. When i start the car it holds 20 -22 psi of vac then when it surges it goes down to like 11 psi.

 

[throwedgsx]

Have you messed with the idle set screw at all?

 

[justinhill98gst]

No, I havent touched that, But i was thinking the car was tunned in summer and now its cold out and it might just be that. Is that possiable?

 

[kenamond]

I'd do a boost leak test. If you have boost leaks at the TB/IM gasket, that's a vaccuum leak at idle and could give the ISC fits. I'd make sure you've got the boost leaks fixed before tinkering with the BISS. Did you replace both gaskets (both sides of the TB) or just one? The TB bolts have to come out to change either gasket, so you need to do both at once (or atleast put O2-sensor-safe gasket sealer in there when you bolt it back up). I reused my OEM metal gaskets and put gasket sealer on them when I had boost leaks there, and it's stayed sealed for 8k miles.

 

[eagletalonjohn]

i had this happen on my car like 5 months ago. it was the intake manifold gasket. they suck to change. no room...hope its not that,but you never know.

 

[voodoogsx]

make sure all the vacuum lines on the TB are connected. I've had something similar happen when one of them popped off. They can also back out to the edge and just hong on but still leak....

 

[U2_slow]

http://www.dsmtuners.com/forums/problem-diagnosis/318487-p0505-new-isc-next-step.html

Its not a boost leak BTW, well... mine isn't...