Onebadwedge

iTrader: (1)

I have searched for cars with a similiar cam to mine, 228/228 .589 .589 114LSA Installed +2 degrees advanced.
It seems that others are having the same issues with their similiar
cam as I am.
I have PM'd a few people and they are having the same problems.
However I have read that some people have 224/224 cams
in A4's and say it drives perfectly, just like stock.

What is the big difference with this cam that no one can tune.
I already had my car tuned at a board sponsor for a whole day
and no head way was made. I later took it to another memeber
that does tunes out of his house and he found that the
board sponsor had the front O2's disabled and codes turned
off for a bunch of stuff. So I don't really want to take
it back the the board sponsor, because now I don't trust them.

1. Car surges from 500-1100 RPM at any speed below 20MPH.
2. When completely stopped, the cam surges 1 more time, then
goes right to idle perfectly at 800 RPM.
3. When letting off the brake from a stop and giving NO gas, just
letting the car idle around in a parking lot, in about 20 feet
the car begins to surge. The surge is progressive. At first
it's 800-1000, then aabout 2 seconds later it's 700-1100, then
about 2 seconds later it's 500-1100. It never goes away.
It will continue surging around 500-1100 all around the parking
lot if you let it.


Does anyone have a similiar cam in an A4
that does NOT have these problems?

Maybe I could get a copy of your LS1Edit file from your tuner?
OR
Some advice on what to do or what to ask the 2nd tuner to
do? The 2nd tuner is willing to work with me.

I've been driving it like this for months now and it's REALLY
getting on my nerves.
Thanks.

jimmyblue

iTrader: (11)

I believe the surging is all about mixture. That's the
lower end of the VE table, for idle, but really the
whole thing wants to be worked over to model the
changes from cam, heads, headers on this car. The
cold idle is probably also affected by the open loop
fuel air table's excessive enrichment to high MAP,
low temp operation (cams make high idle MAP). The
other element in surging is bogus trimming by the loop
in response to the O2s being cooled by the headers.
I would start off with a pair of 'Vette rears swapped
into the front positions before chasing the rest of it.
Then try and tune the idle mixture in open loop mode.

John_D.

iTrader: (2)

One of the things I did was flatten my timing curve in the 400-1200 range.

So the pcm didn't start advancing and retarding the timing if a surge did start, which would make it swing even harder...

I'm running a 224/228 115 +4.

I also did the VE reduction at the low end that somebody posted on here, maybe in a sticky about surge.

Mine only surges on initial startup, and after it's been running about 30 seconds it's fine.

WS6snake-eater

Hey Jimmy I didn't know that the rear o2's from the Vette would work in F-bods. I thought the wiring was different. I'm about to replace mine, they are not "in sync" well, and I was looking for some alternate o2's to put in their place. Are the vette o2 wires long enough to fit, or will we need to make extensions like we do with the F-bods? Also, do you happen to have a part number and are there any alternate A/M ones available as opposed to the high priced GM's? Thank,

Matt

Onebadwedge

iTrader: (1)

Thanks for some quick replies.

I have noticed that now in cold weather(ohio, about 40 degrees), that
the car runs fine for the first 30 seconds or so. Just enough time
to back out of the driveway. I start it and let it set for about 10 seconds.
Then I put it in REVERSE and idle out my driveway.
It "idles" back out at 800 RPM
for about 10 seconds it takes to get out of my driveway. It's fine.
I wish it drove like that ALL the time!!!

Then I drive about 1000 feet
to a STOP sign and if I just "idle" out onto the next road, it's
already surging.

Is there someway I could make it run like it does in the
first 30 seconds ALL THE TIME...?

THanks

Bill Bowling

iTrader: (6)

I just installed the Bosch #13111 that are rear vett. The wires are real long. Connectors are the same. I noticed my O2 are tracking very close to each other since I installed the Bosch. I also think mine readings are closer on WOT.
AdvanceAuto has them for about $75 with one year warranty.

Bill

jimmyblue

iTrader: (11)

Thing about that "shave the bottom 3 columns
of the VE table by X, Y and Z" advice is, it
really depends entirely on your engine's real
VE w/ RPM. What works for one cam may be
a little long or a little short for yours. Using the
O2s to judge, is best. But if the O2s are
untrustworthy that's a problem.

It sounds like the open loop fueling may be a
player too, by the description. Check your idle
MAP and the ECTs where you do, and don't like
the operation. You're probably indexing to a
point on that table that is over-enriched and
shaving it down, at idle-MAP and lower MAP,
can really settle down cold idle surge. Especially
if your idle "snaps in" right at the ECT where you
go closed-loop.

Slowhawk

iTrader: (12)

A4 cars with bigger Cams just need different type of tuning compared to M6 cars.I can see tuner's having problems if they do not tune too many A4's.I've done a few with Cams bigger than 230/230 and they all drive perfect with no surging/stalling.It's mostly idle air,timing,L-terms, and very minor VE