I did a motor swap a while back and have been slowly pecking away at the car trying to get it on the street this spring, a year behind schedual.... car ran like crap for a while and after tweaking this and that and a new opti it seems to start and run fine. I put LT headers on at the same time so I need an exhaust, but I figured that would be the last thing I did, since I dont need it streetable yet. Even tho the cars running better and starting good, it still smells a bit rich and idles high, could the exhaust help this? if the open lts are the problem wouldnt unplugging the o2s eliminate the problems? pcm for less tune btw

 

A cam that size is going to have a very noticeable smell at idle. You could try putting cats on it but all that did was give me the rotten egg smell all the time instead so I took them off.

 

The rich smell, I wouldn't be concerned about, especially with open headers. The high idle would concern me. You need to find out why it's not idling normal. I have a mail order tune and my tune is set for 750 rpms. You may have a vac leak, or a sticky IAC.

 

I think it would be a wise idea to have a "dyno" tune especially with a head/cam swap. I would't rely on a mail order with that set up.

 

^^Some good points here about the vac leak or IAC. I would check for vaccum leaks first with a can of carb/brake cleaner if its not obvious like a briddle hose etc.

If its a new TB you might have to adjust the idler screw, make sure the blades are hanging to far open with no throttle applied...this will cause that also.

I had this same issue...was checking everything...after talking with my tuner he said some PCMs are just lazy and learn the new setup slower than others. The more drive time I put on my setup the better driveability got. Now idle problems are near to none, check fuel pressure and for codes also to be sure your opti isnt acting up.

 

Another clue to a VAC leak would be a high long term fuel trim. You should get it scanned. If you are running open headers with o2's connected, you will want to runs some 18" extensions off of the headers or it will throw the o2's off and run like ****. But that's a separate issue from the high idle.

 

belated thanks to u guys ill get it checked out

 

After my cam istall I had idle issues while coming to stops and applying brakes but after more time my driveability got much better, My car runs really good(NO-tune) but It does run a bit rich and under 1,800 it seems to studder but clears up instantly!

Put some miles on it...

 

also check to make sure the MAF is not dirty or faulty.

 

Hitting the brakes will cause the brake booster to evacuate some of the vacuum in the intake manifold. I would check for vacuum leaks.