I want to know about cam surge

[Joey7508]

I have been reading about cam surge. What I have read has mostly been on efi GM products. It is explained as a slight surge while driving under 2000k that is not present at highway speeds or any other time. A lean condition from running a bigger cam mild to med. ON some of there forums they say a tune can minimalize it. I have just been googleing it. Don't own a GM product. Just wondering if any one here has had that problem and determined it to be cam surge? I am having that problem on my 5.0 right now. And yes I checked the surging idle check list, pulled codes (11), checked for vacuum leaks. Iwould love to hear ideas but I mostly want to know about cam surge. Is something that really requires tuning out or just a name for "I can't fix my surge so I'll call it cam surge".
One other thing I was wondering is would having a f303 cam and a gear ratio like 3.08 cause a surge issue? I know it might get in the right rpm quicker with a better gear but would or could it make it surge below 2000K?

 

[Celeb]

When you say surge, do you mean like erratic idling or low rpm cam bucking?

 

[Joey7508]

low rpm bucking. But not violent.

 

[Celeb]

Mine does that. But I spend alot of time in low rpms in traffic plus my car isn't geared right for it. I doubt you're going to be able to tune that out, short of getting lower gears or swapping cams.

Are you running an F cam?

 

[cenok is family]

my car used to do that. except mine was linked to a rich condition/disconnected MAF sensor. since fixed the issue and it no longer does it.

 

[Joey7508]

swapped gears this weekend. Still surges in same rpm area, but the gears make all the difference performance wise. went from 3.08 to 4.10 for now. I will go back to 3.08-3.27 when I sort out the surge and get my turbo set up back on. I have alot of extra stuff sitting around so ity doesn't cost me anything but time. Oh and I run a vipert56. But just wanted to say it didn't change the surge.

 

[liljoe07]

Where is the timing set at?

 

[Joey7508]

12*

 

[Joey7508]

tried it at 10* didn't seem to make a difference. Here is somethign I have figured out. Is that on a cleared computer it does not seem to be there. Once it relearns it seems to do it? Any ideas on that?

 

[stykthyn]

I used to have that, but it was timing issue. finally found the sweet spot and it went away

 

[liljoe07]

Whats the manifold vacuum at idle?

 

[Joey7508]

13

 

[liljoe07]

E-cam?

 

[Joey7508]

f303 1.6 rockers

 

[liljoe07]

Posted via Mobile Device

Vacuum is kinda low for the F-303 cam. I still have that cam. I pulled 17"-18" of vacuum with it. Maybe the rockers are little to tight.

 

[Joey7508]

I'll try the rockers this weekend see what happens. I'll let you know thanks for the suggestion. I have been thinking about that but didn't know what other people got for vacuum on that cam.

 

[mike0227]

CAM SURGE

I have the same problem and have been trying to tune it out of the 140-1600 RPM range. Other than that the car runs and idles fine thanks to the tweecer.

Please let me know if you find solution and I will do likewise. This has been going on for years. P.S. I use F-Cam and vacuum is about 13-14.

 

[Joey7508]

mike0227 I read your post a little late, I readjusted my valves just to make sure the only thing I had not checked twice. Vacuum still 13-14 no change. I will know more about it. I won't give up till I figure it out.