help, wierd idle problem (not surging)

[dsmoverboosted]

Well when i drive my car the idle seems to rise on its own and i am not sure what to do about it. Now its not surging, it stays at a constant rpm (maybe jumps around 100-200 rpm) but it will start at a normal 700 rpm and it can climb as high as 1800 rpm after driving around for a while. It doesent seem to be related to the car getting hot because I had her idle for 30 minutes and took her for 2 small drives around the block on a hot day with the idle not moving from 700 rpm but it seems to climb if i drive lots. It almost seems like it rises 200-300 rpm at a time. I will start at 700 then its 900 then 1200 then 1400-1500 ect. what could be causing this?

I have recently blocked off the isc, fiav and the egr valve and i have a problem with backfiring (i think i need a new coilpack). I did a boost test and I got a small leak at my shaft seal but thats it. I also just checked my ignition timing and it is fine. This idle is driving me nuts , any help would be apprecitaed thanks.

 

[majik2k5]

Check for leaks around your throttle body gaskets. That can cause an unpredictable idle such as yours sometimes. If there's none then maybe try adjusting the BISS. There are two wires you need to ground in order to adjust it, do a search on here for adjusting it and it should pop right up.

 

[jott5555]

its got to be the fiav.. has the little wax pellet that melts bla bla bla.. most people slam me for this.. and say its just putting a bandaid on a gapeing wound but.. i just like to block off the fiav and isc completley.. and use the biss as a manual idle screw adjustment..

 

[dsmoverboosted]

Check for leaks around your throttle body gaskets. That can cause an unpredictable idle such as yours sometimes. If there's none then maybe try adjusting the BISS. There are two wires you need to ground in order to adjust it, do a search on here for adjusting it and it should pop right up.

I did a boost test and the only leaks i had was at the shaft seal and the bisss screw. I replaced the bisss screw o ring and that fixed nothing. Also I have adjusted the bisss and my base idle is about 750.

I took a real close look at my idle yesterday and I now beleave it is related to the outside temp, it doesent jump around when I first fire up the car and even when the water temp gets to 95 degrees c the idle is a solid 750. It seems to get all screwy when it is hot out side and i drive it around for a while. Last night it was kinda cool and I drove around for like 4 hours and my idle was like stock the whole time. Today it was hot out and after my 30 minute drive to work the idle hit 1000 rpm and bounced around between that and 700. I also backfire and "pop" way more when its hot out and the idle seems to be screwing up.

I read that it might be a bad cas. I am going to swap mine for one i got sitting in my garage and see if that helps.

Oh i also cleaned out my throttle body with carb cleaner today but i have yet to drive it, maybe that will help.

its got to be the fiav.. has the little wax pellet that melts bla bla bla.. most people slam me for this.. and say its just putting a bandaid on a gapeing wound but.. i just like to block off the fiav and isc completley.. and use the biss as a manual idle screw adjustment..

I did this already, I blocked off the fiav, isc and the egr.

 

[dsmoverboosted]

Well I swapped the cas with no luck . I still ride between 700 and 1200 rpm and "pop" and sputter like crazy. I cant go over 5000 rpm also at wot because it backfires so I am thinking the 2 are related since I have done everything possible to fix my idle to no avail.

I got new plugs gapped to .28, new wires and I have replaced the cas. So what does this leave me with? As far as I know the only thing left that could be causing this the coilpack but thats a pretty expensive buy and I want to check everything else first before I go buy a new coilpack.

What else could cause this popping and backfiring besides the coilpack, wires and plugs?

 

[dsmoverboosted]

anyone?

 

[dsmoverboosted]

ok it just got worse. I cant drive it without it backfiring, missing and poping like crazy. I cant accelerate anymore . I thaught it might have been a vac line that popped off but i did a boost test and there is no leaks.

I was playing around with the connection from the engine harness to the coilpack harness and if i push the harness together and up with pretty good force the engine revs high then if i let go it drops again. I dont know if this is normal or not but it seems odd to me. also before today my stock boost gauge was pretty much the same as my aftermarket gauge (they both read about the same boost) and now my stock gauge goes up to 1 bar when i am at 4psi on my other one. Even when i rev it in neutral my stock gauge hits almost 1 bar when my aftermarket one goes no higher than 0.

So does this have to be my coilpack or is there anything else I can check first?