itsslow98

iTrader: (18)

Thanks in advance for the help, i have a 98 ss and before it would idle in drive from about 700-1300 up and down at stop lights but it would not do it in nuetral. Then it started to do the same thing even in nuetral but the car ran fine otherwise. Now, the car will idle at 1300 all of the time and will not go down? I am thinking IAC or TPS or a dirty throttle body. Any other suggestions? I did a search and nothing close to this seemed to come up.

Blackhawk777

Dirty MAF and throttle body is most likely the culprit.

LT1PwrdZ

iTrader: (1)

Idle air control, Throttle position. Probably not a dirty MAF. They are picky and will throw and code. Clean the throttle body and sensors to start

Schnell

Vacuum leak.

LastHawk

My car is doing the exact same thing. I just cleaned my MAF too so I am not sure what the problem is.

itsslow98

iTrader: (18)

cleane the IAC and it seems to be helping. The idle in drive is now at 950 but smooth and now it seems to be idling around 1000 in parkl but the idle is a tad up and down but better overall. I havent touched the throttle boddy but I assume it is clean because I had the ls1 intake swapped for an ls6 a few months ago and the mechanic shoudve cleaned it when he reattached it.

itsslow98

iTrader: (18)

ned some more help, the idle came down but now its idling up and down again. i cleaned the IAC and replaced the throttle body because the one that was on there had a few cracks in it and was causing a vacuum leak. The number 2 cylinder is missing a lot and i just changed the plugs and put new wires on it. The fuel injector is functioning properly. I don't know what to do. The code that it is throwing is P0507 which means "idle control system RPM higher than expected". Do you guys think that the IAC is bad or is it a different problem. Please help. Thanks again.

bene

iTrader: (16)

You have a leak somewhere. Check your vacuum lines. If you changed your LS1 intake to LS6 intake, you might want to check your MAP sensor at the back to see if its on there pretty good.

SparkyJJO

iTrader: (11)

Make sure the whole intake is bolted tightly too, if it is slightly loose it can cause a vacuum leak. Someone here had that as his problem.

itsslow98

iTrader: (18)

ive sprayed all of the way around the intake while running and now vacuum leaks there. im at a loss all I can think of is IAC is bad.

LastHawk

I have seen many posts about this very same problem. Everyone's suggestions are great but many of us still cannot find the culprit. My car is essentially stock but still has this problem.

It is not consistent a problem though.

First instance of this happening was a few years ago. Lasted maybe 2 days and was gone. Then maybe a year later, it would happen again for a day and dissappear. Just last week, the car started doing this again, lasted a few days, and now idles/drives 100%normal again.

I've heard of people replacing the IAC, MAP, MAF, TB etc etc. It seems this problem is fairly common but noone has cited a "this fixed it".

If this was a vacuum leak, would it really correct itself over and over again? My MAF and TB are cleaned and secure. Intake has never been removed. Have never isolated a vacuum leak any where in the engine bay. I give up Maybe just put it in the same "POS" category as my window motors and DRLs..It's just going to happen.

I just don't get it.

Phil8616

iTrader: (11)

Believe it or not I had this same problem, I found that the hose that runs from the PCV valve to the throttle body was torn/cracked and the PCV valve was clogged up. It caused me to hang at high RPMs and idle high which threw a code eventually. Its on the left side near the EGR crap if you have it. Goodluck.

-Philip

jattgunman

iTrader: (1)

Did you recently do any mods to the throttle body?I had the same problem in my car it would only idle at a complete stop not while rolling...I tightened the intake manifold,checked for vacuum leaks,cleaned out the iac(full of metal shavings) and tps sensors a good 5 different time and nothing.adjusted the blade and nothing helped..Turns out the guy who ported my throttle body did a crappy job and overported it.. WELL I put a bolt and nut through the blade hole and now she runs perfect..

hope that helps

itsslow98

iTrader: (18)

ill give it a try thanks for the help. im getting so frustrated ive considered selling. i was trying to get this done for ocean city hot rod week which is next week.

Xtreme57

iTrader: (6)

did you ever fix this issue? I'm having the same problems ... and yeah, it's effing aggravating!