Help! 16V High RPM Miss!

["Shannon Fenton" <sfenton@amazon.com>]

Well as many of you know I have been having some pretty bad probs with the
car since the swap to Schrick 276 cams. I have been working pretty much
every night on the car trying to find the prob but Im now completely at a
loss and frustrated as hell. Read on.

Problem: Car misfires at high RPM. Usually starts at 4300-5000rpm and will
effectively prevent any further acceleration. The miss feels like a soft rev
limiter. The miss is less severe when the car is cold but still very
prominent. It all most feels like I am running out of fuel intermittently,
but the car is coughing great clouds of black smoke and I get small children
high off the fumes while idling at stoplights. Going stop to stop on the
mixture screw has little effect on the miss. This leads me to ignition but
all components check out and/or have been replaced. Car never did this
before the cam swap.
One thing we have found while testing is that above 2K rpm I am losing all
ignition output from the coil. This is evident in a audible miss and black
spot in the timing light strobe. Underway this cannot be felt, unless this
lack of ignition is only appreciable while underway at high RPM.

The prob was initially worse when I did the cams, I did some testing and
took it to Momentum due to ND coming up and time constraints. We put in a
brand new distributor, checked all grounds, swapped in a newer coil and the
ignition could still be seen cutting out on the timing light. But after the
coil swap the prob could no longer be felt. Drove all the way down to CA
prob free even with the miss still showing up on the timing light. Shut the
car off in the hotel in CA and upon restart car missed worse than it ever
had.

Variables checked:
WOT Switch in and out of loop, no difference.
All TB Switches in and out of loop (unplugged TB wire harness), no
difference.
A/C Idle switch in and out of loop, no difference.
Knock Sensor in and out of loop, no difference.
Timing good.
Intercam Timing good.

Things checked/replaced:
Swapped Knockbox
Swapped ICM
Swapped FI computer
Swapped Fuel Pump Relay
Swapped Coil
Swapped Coil Wire
Brand new Distributor
Checked and rechecked all under hood grounds
Cleaned all under hood grounds
Mixture setting has very little effect
Timing has very little effect

Components Changed wCams:
Valve Springs
Valve Guide Seals
Intake Manifold
TT Adjustable Cam Gear (set at 0 right now)

Please help...these cams are no fun w/o letting them unwind. I probably
going to take the cams out in the next week or so and hope the prob goes
away with the stock cams. Arghh...Im at my wits end.

Shannon Fenton
Telecom Resource Management
Desk 206.266.6736
Cell 206.953.6170
Pager 206.541.7831
http://internal.amazon.com/it/infrastructure/telecom/
www.amazon.com


--
Email LIST problems to: scirocco-l-probs@scirocco.org.
To unsubscibe send "unsubscribe scirocco-l" in the message to majordomo@scirocco.org