tuning problem?
 

I recently had my 422 cu in iron block tuned. The 600 plus lift cam with 236/242 @.050 113.5 ls. idles good at 900 to 1000 rpm. But I am now experencing when it is in gear and rolling it wants to idle at 1600 causing the car to idle at 43mph on level ground. To cruise around i am riding the brakes and the converter keeps going in and out of lock up every time I step on the brakes(I know this is normal) and it heats up the trans fluid trying to stop is hard. If I am in traffic I have to put it in neutral evry time I stop or it will start to run hot because it is under such a load idling in gear. I have a TCI 3200 stall on hp 10" converter. My question is how can I get the car to be more drivable with out idling so high in gear. if I could keep it idling at 1000 rpm in gear instead of 1600 I would be really happy. I was told that if the tuners were to turn the idle in gear down and the rolling idle down it would set codes. I assume misfire codes from the irratic idle. I have been told that a looser converter would help also but the cam and heads and gear are matched for the converter if I go higher I will lose the combination. Any Ideas would be great Thanks Rich

Whoever told you that it would throw codes is full of crap. The problem is the tune itself. What you're describing is the "cruise effect" a bad tune will cause. Sounds to me like someone just slapped some cookie cutter tune on the car, and didn't bother to actually spend time tuning it the correct way. I'd take it back to whoever tuned your car and demand they spend a few hours fixing it. If they can't, get your money back and get a real tune. Or purchase Edit or HPTuners and do it yourself.

Thanks I thought that it was in the tune. with the stock tuning it idled real bad and it was throwing mis fire codes but it was trying to idle at 600 rpm like a stock motor. Thanks again Rich

The tune is not correct for the Cam's LSA and the timing and VE is not correct. Screwing with the idle RPM is only a bandaid and not the correct solution.