Engine swap, idle problems, popping and bogging - Third Generation F-Body Message Boards

techno101 · 07-16-2006, 03:52 PM

Ok so I've been working on this swap for months now. 350 TPI, Speed Density. Thought I had everything working ok but the stupid thing won't idle right. I tried the IAC reset and adjusted the idle screw. It wants to die if it gets below 800 RPM. Its set at 1200 in park and it idles at 1000 in drive. Way too high I know but I don't know what else to do.

So I finally get it to idle half ***, rough idle though, and not from the cam. Theres a miss or something in there too, thought I'd add that. Well I say lets take her out for the first time and see what happens. Engine boggs a little and doesn't have the full power it should. Also sounds like a pop is coming form the engine while under a load (only in drive though, in park it runs ok, not great though). Tach is jumpy also. Jumps up and you can hear a slight miss or something I don't know. this may sound dumb but this is how the engine sounds at 2500 rpm, booooooooooo boo boooooooooo boo booooo boooooooo boo. Know what I mean?

Timing is set at 6 degrees. Has a custom chip from PCMforless, for VATS, larger injectors, emission controls, things like that. Engine has aftermarket heads, aftermarket cam, shorty headers. Ported/polished TPI intake.

So should I just try to find somewhere that has a dyno and tuning abilities or has anyone else had similar problems??

87zjeff · 07-16-2006, 04:29 PM

check for vacuum leaks. it's the most common cause for a rough/erratic idle. they can also be a pain in the a** to find

techno101 · 07-16-2006, 06:44 PM

I've checked everywhere for leaks, I haven't sprayed choke cleaner around yet though.