ele-blue95

iTrader: (10)

I have a 99 6-speed with a 413 ci. with a 251/257 dur.@600 Lift 114 LSA cam,Stage 3 ported heads w/ 2.08 intake 1.65 exhaust valves, oz700 clutch, LS6 MAF, LS2 ported intake, LS2 ported 90mm TB, 42# inj., SLP long tubes, X-pipe and borla cat-back. I just dyno tuned the car today. The problem im having is a low RPM surge around 2600 rpm and lower, in all gears. The problem was present before the tune and is still there, the tuner did all he could to fix the problem with no luck. Could it be something other then cam surge? After 2600 rpm the car is a beast and runs great. Any help would be great.

Plus the car has a really hard time starting up. It threw up a cam position sensor code. any ideas? And were is it located?

diablotoona

Sounds like tuning issues to me. Maybe the tuner was not experienced enough. Idle tuning is a PITA and takes some time.
Is the car trowing and codes?

ele-blue95

iTrader: (10)

It is throwing a code for the cam position sensor-broken cir. but that is it.

diablotoona

I would definitely get that fixed but i am pretty sure it is still a tune issue, but i would eliminate everything else before blaming the tune.

wait4me

iTrader: (10)

Yeah like diablotoona says, get that code fixed. IT is pretty important.

Also did you just call the place that did your tune and tell them about it? It is a simple fix, but all issues have to be told to your tuner so they can fix them.

ele-blue95

iTrader: (10)

I called him and he is looking into it. And im looking at fixing the other problems today or tomarrow.

wad02z28

I assume that your running ls2 style front cam position sensor. If so some extenstion harness the ones i've used the two outside wires need to be swapped. This will cure the hard starts and code . As far as the surging goes that is a fairly large cam so you may have to live with some surging. Are you running maf or sd.

ele-blue95

iTrader: (10)

It is running LS2 everything. I will try and swap the wires and see what happens. It is running a LS6 MAF. I think the ported LS2 TB may have been ported wrong. And were is the cam sensor located, is it on the intake or the timming cover?

wad02z28

Its on the front of the timing cover.

ele-blue95

iTrader: (10)

Sorry guys. It is a 6.0L LS1 Iron block with stage 3 ported 853 castings, LS2 intake, LS2 Ported TB.

Tyler valo

iTrader: (3)

I have the same problem you do with almost identical specs (418ci, 251/258 cam at 114lsa) and the things is an absolute dog under 2500rmp but after that it's a beast. Did you ever figure it out?

edcmat-l1

iTrader: (10)

Who speced that cam? Where is the ICL? Who tuned it? There's only so much you can do tune wise to tame a cam that big. Depending on some mechanical issues, it may or may not be able to pick up any low end, in other words cure the "absolute dog under 2500"

What is the ICL? What is the compression? Is it speed density tuned?

Tyler valo

iTrader: (3)

The short block I bought was assembled by a local reputable builder and he talked with compcams to spec the cam, I'm not sure of the ICL. It was tuned by the same guy, but it wasn't SD tuned, I'm running the larger 85mm MAF.

edcmat-l1

iTrader: (10)

That big of a cam really needs a sd tune. If you're running on a stock VE table, that's part of your problem, unless the VE has been disabled, and even then I'm not sure that it would run good. I've never tried to run 100% MAF on a cam that big.

Tyler valo

iTrader: (3)

Do you think you could make it a little more drivable? Virginia isn't that far for me, I could make a trip to your shop one day.

01FbTaWs6

iTrader: (12)

if anyone can make it run better, it would be the fella above....

Slowhawk

iTrader: (12)

I'd probly bet they used the wrong Cam gear.Had that problem a few times with recent builds customers did at home.They put a 4 point gear(made for E-38 PCM's) on the Cam.
It will throw codes and startup like crap.

Tyler valo

iTrader: (3)

I don't throw any codes or anything. The motor is an LS3 block in a 2000 C5.

edcmat-l1

iTrader: (10)

I could make it drive as good as it will get. That's a nasty cam. It will never be perfect. But, chances are, the way it drives now can be greatly improved upon.