I have the same problem on my VIII with 272 cams. I had my ecu flashed after the install so i thought that would take care of it but i was wrong. Still can't figure it out has any one found a way to fix this yet?

 

gonna bring this one back from the dead in case anyone has found a fix yet. Same problem...idle stumbles down to around 500 or so and goes way lean then catches it self and goes back up.

fixes?

 

i've been tuned and raised the idle to 1k rpm and it still dips - gonna have Sean look at it this week and I'll post up results, just do a friendly bump on Friday if I've forgotten so I can remember to discuss results. . .I'm on GSC S1's. . .

 

thanks

 

Im getting cams installed this weekend and if this is gonna be the norn, then I might just back out of getting the cams installed.

 

i am curious to see how many people DONT HAVE this problem...

i have even left my car on idle for several minutes and the only rpm change i change is a slight movement when the fan goes on... as soon as it stops the idle falls to normal rpm and its almost rock steady...

 

went to Sean Ivey today to get retuned with the exhaust and have the idle issue taken care of - he managed to eliminate most of it, ECU is still relearning, but he raised the idler on the TB and did "something" in the flash. . .it should hold, feels amazing:

 

ya i have the same issue with my cosi M2s i wonder if its a tune issue or if it can be worked out or im gonna just have to deal with it

 

Just something I noticed last night and to add to discussion.

I normally run 93 octane from Shell but last night I filled up with unleaded 100 octane and although the car's idle still behaved the same, the AFRs never rose above 16.1 which is odd because it used to stumble into full lean "- - -" at idle.

The wierd part is that it still behaved the same, would stumble then after a few seconds surge slightly but this time the AFRs were almost "acceptable" Anyone else experience the same thing or have access to a higher octane fuel to see if this can be replicated?

Anyone smarter than me want to take a stab at whats wrong with the cosi cams, or my setup?

P.S. At cruise and WOT my AFRs are in check.

 

On joel(pa)'s car I increased the timing between 9-12 degrees at idle. I also messed with stepper values at idle to get it to idle better. I increased his idle to 1100 and it is idling a lot better now.

Maybe he can chime in here...

If anyone wants me to help them out. Take a log at idle and send me your map/xml def./log for your car and I can do the same thing I did for him to test and see if it helps....

~Zach

 

Need to take care of a few things on the car tonight but I'll try to button her up and get some logs by this weekend.

 

i put supertech dual springs in my car today and the idle is now fine.

How many guys running cosworth with the bad idle are still on stock valvesprings?

 

It took a while to find the perfect settings on my BC 272's. Never had to touch the idle screw.

Now mine idle like stock never dip or surge anymore

 

i thought the 9's shouldn't idle rough cammed thanks to MIVEC. Can you guys post what the vacuum gauge reads at idle?

 

i don't really have that issue. still on stock valves & retainers. vacuum is around 10-15 if i remember correctly.