86 newbie

Hey guys so i have a 86 5.0 i recently put ported e7 heads and a cobra upper and lower intake on it. I had put a x-303 cam in it but i couldnt get the idle to come down. It would hang around 3k. I put the stock cam back in it and the idle still says high but now its at about 2k. I checked the timing and i put it to 12° i tried to base idle reset it and even disconnecting the iac valve the idle wont come down. I checked for vacuum leaks and couldnt find any. I need help. Thanks.

88 orangepeel notch

Have you checked for vacuum leaks using a smoke machine ? That's the accurate way to do it.

Your symptoms point a major vacuum leak.

86 newbie

I dont own a smoke machine. Is there any different vacuum ports from a oem intake to a cobra intake? Something im overlooking vacuum wise? Could it be in the computer? When i take the vacuum hose off for the map sensor it idles down to 900 but misses really bad. As soon as i plug the vaccuum line in the rpms shoot to 3k but doesnt miss and sounds good.

88 orangepeel notch

Are you still running Speed Density or did you convert to Mass Air ?

I'm not sure on this, but Speed Density is not as forgiving when it comes to mods, and maybe your at the limit with that cam.

Hopefully someone will chime in who knows more on the limits.

Also, you can make your own smoke machine if you wanted to. There's a nice step by step write up over on the Corral Forum, in the General Discussion I think. It's a sticky.

86 newbie

I put the stock cam back in it.

88 orangepeel notch

Well, this is a real pickle.....

My bad on the cam, sometimes I reads faster thans I looks.

Try disconnecting the battery to reset computer, and I'm assuming you've checked for any obvious things that would hold throttle body open, slack in cable, idle screw all the way backed off, sticky pedal, sticky throttle body, etc

I'm just shooting in the dark here as I'm not a Speed Density guru. But it sure sounds like a vacuum leak somewhere. Wish I could help more....