Okay I've had my cc306 ported heads and other mods on car for about 8,000 miles now. and I have a surging problem, since h/c install and I even got the car finished with a live tuner. the tune is pretty much on. only problem Im having is some surging. at lower rpm's just cruising and It is really noticeable cruising 2500-2700 rpm's. about 65-75 mph. I can feel the car surging. almost like a strong head wind buffeting me. not real bad, but I notice it all the time. drives me nuts... are any of you 306 owners getting surging cruising at highway speeds. maybe I have to get my tune better?

 

I have the same problem with my setup. I have gotten used to it and accepted the fact that below 3000 rpm's, my car is not that impressive. Your automatic is not helping the situation either. The lift numbers on the cam like alot of airflow.

 

I don't have cam surge........as hard as that may seem to believe I don't.

 

check all your vacuum fittings, hoses, connectors, and all the electronics/hardware that connects to them. i had a hairline crack in one of my lines. still have some reverse/first issues and some issues when i come to a halt, but my surging is gone in the rpm ranges you speak of

 

I wonder why I am having the low lift surging then. I have had several dyno sessions with some respectable numbers, but normal everyday driving is something that I have gotten used to.

 

I have no surge at all, it is also a 6-speed so i'm sure that helps a bit. My friend tqdrivenws6 hooked me up with a tune right on the money

 

Idle air counts? Should be around 40 if higher it can cause surge

 

Well, I am getting new heads in the next couple of months so I will wait to retune the motor and see if I can fix the problem.

 

For one thing guys, a 6 speed will actually allow you to feel the surging more. An automatic, especially with a stall, has some give and the surge feels a lot smoother or even nonexistent.

For 93yellowta, I would say that it may be something besides the tuning. Usually, cars cam surge at lower rpms than 2500-2700. I take it that it clears up beyond that point? Does it miss at all at those rpm at WOT? Are you able to scan the car to see what it's doing (sensor-wise)? The CC306 is hit or miss with cam surge, but it's usually in the tune. I'd say, if it was surging at 1500-2000 rpm, it would be the tune (remedied by retarding the timing a bit in the problematic area).

 

This is true. I had an automatic in my car for about 2 weeks and yanked it out because i hated not being able to shift. It did the same thing with the auto though.

 

306 shouldn't surge that high up. Above @ 1800 my 306 drove like stock.
Even the 847 doesn't really surge much.

Thowing more fuel and timing at the areas where it is surging usually helps.

 

I'm not sure on the fuel, but I take care of surging by pulling timing.

 

I don't really notice it over 2700 rpms. wot runs like a beast no missing thru any rpm's at wot. dosen't seem to be missing. On my autoxray some split blm's at idle, but gets closer during driving. longterms and shorterms seem to try to hang around 128's. they go up and down. 02's are switching fast. ac delcos' about 4 months old. my iac counts are around 58 at idle car in park. in gear foot on brake around 108's. and going down road 120's... throttle does seem to hold alittle too long when I let off throttle. kinda like a vacuum leak. I cant seem to find any..replaced 1/2 of the lines. car pulls around 10-11' hg's of vacuum.
map reads 2.7-2.9 volts at idle. and the tps reads .56volts at idle.
no codes. my wife can even feel the surging in the rpm's. on one other note, I have a stock stall in there now, heres why. my first tranny went out, put in a 700r4 but it was modded for non-lockup, could not find a non lockup high stall around in time, so I put in a so-called test stall from a tranny shop, non lockup, but stock stall speed. really fun trying to hold on the brakes at a light..
could that be why, Im putting in a performabuilt stage 2 4l60 in feb. with a yank ss3600 stall, would that take out my surging?

 

That must be a really tight converter if it's wanting to pull at stop lights. Stock stall speed is 1600 rpm. It seems like all of your sensors are within spec. Have you checked the knock retard? You may just have a touch too much timing (not necessarily enought to cause knock though) in that cruising area, but, like I've said, cam surge (from too much timing) usually happens at a lower rpm. I can't think of any reasons why you'd get surging that high in the rpms (cruising) and it runs smooth everywhere else. Maybe it's the 'experimental' stall doing something funny. The 3600 stall will probably rid you of the feel of the surge. Is your tuner local? You may want to ask him if he can take a couple of degrees of timing out in that spot to see if it goes away. If everything checks out and the stall gets rid of it, I wouldn't worry about it.

 

yeah he said that the stall he put in, would pull at lights, it has no stall at all pretty much... only knock I pick up is 1 degree when I run 89 octane and at wot. at 91 octane I don't pick up any. I try not to run 89. but that is all there is in our small town, and Im usually out of fuel on my end of town..

Im pulling 22-25 degrees at idle, it's jumping around from the lope.
at 2200rpm's it's at 44 degrees. I just parked my car for atleast a week or two. were expecting ice/snow tonight here by KC. what I'll do is when I get my new tranny in and stall I'll see how it does then. I'll keep you updated...