406chvycamaro

iTrader: (7)

I recently got my ls swap running and trying to sort out a few bugs. When idling it surges up and down 200rpms, when I throttle the engine up and hold it it sounds good but when you let off and it goes back to idle it sort of stumbles and dies. The last thing it's doing is I revved it up to 2000 rpm and when I let off it stayed at 2000 then surged to 2700 so I shut it off. Does anybody have any idea what could cause these problems? Possible one thing could cause all of this?

Jimbo1367

Are you sure to have the oxy sensors hooked up ? Do you have any codes?

406chvycamaro

iTrader: (7)

Yes I've got the 2 front o2 sensors hooked up the back 2 are tuned out. Not sure as far as codes I don't have a scanner

98CayenneT/A

Try cleaning the air idle control valve

Old Geezer

iTrader: (3)

Get a scanner.
Also, do some data logging.
Without those tools , U R guessing and throwing $$ at the problem[s].

406chvycamaro

iTrader: (7)

I removed the iac and it was coated. Is the plunger in it supposed to move freely?

98CayenneT/A

Ya, it should slide a bit, I would clean that, throw it back in and give it a wirl

406chvycamaro

iTrader: (7)

It may have helped a little bit but it seems to be doing the same thing. The plunger was hard to push in and after pushing it in I can't pull it back out

98CayenneT/A

How long did you let it idle for after cleaning it?

406chvycamaro

iTrader: (7)

About a min as soon as I gave it throttle it sounded great holding it there but died when I let off

98CayenneT/A

I would clean it again with carb cleaner or something then let it idle for a few min and let it adjust then give it some gas

406chvycamaro

iTrader: (7)

Alright I will try that thanks

98CayenneT/A

Mine did the same thing this past spring after getting it out of storage, would surge and drop or just stay at around 2000rpms, cleaned the valve, put it back in and let it idle for a bit with a bit of surging until idle dropped to normal and have not had a problem since

406chvycamaro

iTrader: (7)

I'm just wondering if it's bad I bought the motor and it had been sitting for a year.

98CayenneT/A

Still the same thing? Was the valve still stuck in when you cleaned it again?

406chvycamaro

iTrader: (7)

When I pulled the iac back out it was out just a little bit but not as far as it was the first time

98CayenneT/A

Did you disconnect the battery to try and reset it?

406chvycamaro

iTrader: (7)

No I didn't will try that

lsxtreme17268

iTrader: (2)

this isnt any help to your problem but you can get a wireless obdII scanner to use with a smartphone for less than 30 bucks off ebay and a free app called torque . Ive used my tons of times , well worth the money

406chvycamaro

iTrader: (7)

Does it do Live data? Do you have a link to it on eBay? Thanks