I just installed a 224/230 112 LSA CC503 in my car, with 1.6 rockers and CMS springs. My idle is pretty crazy, it jumps 100-200 RPM up and down, and the BLM's are split(121 left 129 right) at idle. It lopes like crazy too. It almost seems like a vaccum leak the way the idle hunts around. It bounces between 700 and 900 RPM. I already checked all the vacuum connections on the intake manifold, and sprayed carb cleaner around it to check for leaks.

Could bad rocker adjustment cause this? I went zero lash+1/2 a turn on all of them, but this is the first time I've done it and I'm starting to think I might have messed that up. Any ideas on where to start trouble shooting would be appreciated.

 

It would be a good idea to double check your rockers.Are you on the stock program?

 

I have a mail-order tune from Ion Soltan. (Madwolf) Is 1/2 a turn past zero lash too much? I'm using stock lifters if that make a difference.

On the scanmaster my MAP reading jumps around between 13-16, with the "bar" reading at 29.3.

 

you might wanna try setting the rockers with the engine running. what youd do is simply back one off till it clacks. stop and then listen real hard as you start to tighten it back up. the instant the loud clack goes away you are at zero lash so youd then proceed with another 1/2 turn. of course do this to the rest of them and you are finished... then if the idle still surges you can at least rule out rockers.

 

Update-

I drove it around the block a few times, and the idle seems to have smoothed out. My IAC reading went from ~80 when it was really rough to ~50 now. However, my BLM's at idle are 118 left and 132 right. It feels great when its moving, no surging or missing at all. I didn't get on it or rev it high but the normal driving felt like stock. The idle still lopes pretty good, but the tach isn't bouncing around anymore.

I'll re-adjust the rockers and see if that changes anything. I'm gonna try 3/8 of turn past zero lash instead of 1/2 a turn like I did last time.

 

just to make sure, at which point do you stop and make the last 1/2 turn? when the pushrod loses all up/down movement? or when it stops spinning? it should be the first, otherwise theyll be too tight. just doublechecking to make sure. hth and good luck

 

I spin the pushrod untill I feel some drag on it, while turning the rocker nut by hand. The pushrod stops turning maybe 1/16th or 1/32nd of a turn after what I was using for zero lash. There wasn't much difference between the point where I felt drag and the point where the pushrod couldn't spin at all.

 

how bout trying it the up/down way this time? much easier to discern, and from all the searches ive done on here that way was voted best (if the engines not running). i did mine like that and had no problems at all. tighten the rocker and lift the pushrod up and down and when you feel the gap closing, tightem slower, till the up/down stops. go slowly, otherwise youll overtighten. turn another 1/2 turn, and youre done. the pushrod should still spin after the up/down is eliminated, but probably wont as much after the last half turn. but will again when the lifter bleeds itself (or something like that, but you know what i mean). hth

 

Another update-

At idle, before the car even goes into closed loop, my right BLM is at 137, while the left is at 128. I re-adjusted the rockers, and it does the exact same thing. My right O2 only fluctuates in the 500's when it goes into closed loop. The left one jumps between 400-700. I can't figure out why the BLM's aren't both 128 while the car is warming up like they should be, bad O2 on the right side maybe?

 

Fixed it. I turned the crank through the firing order and tried to move the rockers for each cylinder at TDC on the compression stroke. I found the #3 exhaust valve, and both valves on #5 had zero play in them. On the other valves I could get a slight wiggle out of the tip of the rocker on the valve, but not those. I couldn't even turn the pushrod. I re-adjusted those three the way slashZ28 suggested, and now it runs 100X better in both closed and open loop. I replaced the 02's as well. My BLM's are at 142 on both sides, but they aren't split so I'm sure that can be fixed with more tuning. I also have more vaccum and the car doesn't lope like a freaking pro-stock car now. Thanks for the input guys.