GMH94Z28

Well i am trying to hunt down a mis or a stumble and ran across a thread that explained cam surge. It sounds like what i am having. It is a light stumble when cruising under 2000 rpm. When i get on it it is very smooth. It also doesnt do it until it warms up. Anyone else with this cam have this issue? Thanks

truedualws6

I have a baby cam and at the right times it has some minor surge. Surge is definitely something that happens at normal operating temps and can be especially noticable after a short cool down period when you start up and move at part throttle in 1st gear. For me it's a herky jerky thing where more throttle or pushing in the clutch and giving the engine a little rev is needed. And it happens below 2000 rpm.

You will find many with big cams (GM 847, etc.) claim no cam surge, but I find it hard to believe. I would think that auto cars dampen or mitigate surge much better than a manual.

AdioSS

a lot of it can be programmed out, but it takes lots of one on one time with your tuner.

Big cams have cam surge also, but sometimes it is just out of the cruising range.

wrd1972

Yes cam surge is the jerky behavior you get under 2K RPM when holding steady speed or lightly giving it gas. It most noticeable in 1st - 4th gears and not at highway speeds below 2K RPM. This happens as a result of a lean condition for those particular conditions.

The motor wants more gas under 2K RPM than the (closed loop) PCM is willing to provide and yes a good tune will reduce it but not eliminate it. The way I understand it you can get the PCM to add more fuel but it will be across the board, not just a certain segment.

I can load up my open loop tune which the tuner specifically created for surge which adds more gas under 2K RPM light throttle conditions. Every bit of the cam surge it was totally eliminated.

GMH94Z28

Does it fill like a miss? To me it feels like i am only running on 7 cylinders.

wrd1972

Yeah, it can resemble a miss. Just wants to buck and jump a bit. If it were a true miss, you would feel it and here it when you beat on it.

truedualws6

When my car surges it does not feel like a miss to me.

dre2013

i have that cam..sounds like the surge. either that or could poss be a plug/wire/o2 sensor problem

GMH94Z28

I am looking at redoing my plug wires now.

vin1382

if you have good power with the car and its not shaking or stumbling as you accelerate mildly or at WOT, then its probably surge. my 224/230 has a tiny bit of it when it comes to stops or goes around turns(low rpms). its never enough to make the car die, just sounds a little bit more choppy and the idle bounces for a bit until your at rest.

GMH94Z28

It accelerates fine and WOT is smooth and quick it is just light throttle and around turns.

LaredoZ28

I have the CC501 cam in mine and it surges aswell. i hear its typical for a cam swap.

GMH94Z28

I wouldnt think it would be alot though. Mine seems to be more than cam surge.

GMH94Z28

I installed some new O2 sensors and it feels a little better. Like when i come up to a stop and push the clutch in my rpms dont drop down and then come back up anymore it goes right to 850.

ulakovic22

Catching an idle is a function of the IAC. Have you checked the counts to see if they are in range? Too high and the motor can't adjust enough when you close the TB and too low means you will be sucking air from some other place instead of the IAC.