Late (6800 rpm) cam changeover

[danwasdahl]

I'm having a problem- The car has recently decided
to change cam profile at 6800 rpm instead of 6000-6200. I'm reading
rpm off the dash tach in the usual fashion.
Car is 2005, serial # 40 (An early car). Only 1800 miles. No Mods.
Frustrating- makes an already narrow powerband narrower.
Anyone else had a similar problem?
Thanks
dan w

[catapult]

The problem is you're not driving the car enough.

[Wasabi]

Is the dash reading the RPMs wrong? does the fuel still cut out at 8500?

[danwasdahl]

[quote=Wasabi]Is the dash reading the RPMs wrong?

I have no reason to suspect the tach. However, I have not
tried to calibrate it- I guess it is theoretically possible that
something changed in the tach, causing it to read high. But it
subjectively "feels" like the changeover is late, too...

does the fuel still cut out at 8500?

I don't take the revs that high; 8000-8200 is about as
far as I go before I shift.

Thanks for input
dan w

[charliex]

I'd suspect the cluster before i suspected the ECU/engine, thats quite a change i can't think of any good reason as to why they'd add that.

it'll bounce the limiter at 8500, or youll get shift light

[TimMullen]

Originally Posted by danwasdahl

I have no reason to suspect the tach. However, I have not tried to calibrate it- I guess it is theoretically possible that something changed in the tach

Actually, it's a rather common problem. What does the tach read while idling, and what does it show when the engine is off?

Some times the "zero" point is skewed, and it needs resetting. There are instructions in the Owner's Manual on how to do a "speedometer/tach reset", and several threads on the forum with the detailed instructions on how to do the reset.

[danwasdahl]

Thanks guys- I'll try both and report back.
dan w

[danwasdahl]

Ok- Tach was at about 2-3 k with car off; about 3-4k
idling (didn't have my reading glasses last nite).

This morning
1) I opened the driver door, and left it open.
2) I turned off the security system by pushing the button
on the key fob in the usual fashion.
3) I pressed in the reset button on the right side of the steering column.
4) I turned the key on.

Needles swung below zero; dash showed software version, etc. Good.
I was holding the reset button in all this time.
After the dash display returned to normal, I released the button,
and turned the key off.
Now Tach is at 0 rpm with car off; maybe 800 or so when actually idling. Good.

It's been raining here. I'll test and see if the reset procedure fixed
what has appeared to me to be a late cam changover when it's dry outside.

Thanks guys
dan w

[danwasdahl]

What has appeared to me to be a late cam changover was FIXED
by the tach reset procedure.
Tach was reading high, so it looked to me like the cam changeover
was happening at 6800 rpm.
And shifting at a bogus tach reading of 8000-8200 made it seem
like I had a narrow (6800-8200 rpm) powerband.

Thanks Guys.
dan w

[danielg]

I've tried everything to reset my speedo/rpm. I follow instructions exactly. Anyone know why it doesnt work on my car? my needle reads almost 1K rpm with the key in the on position and my speedo is up a little bit probably close to 5-10mph. and my cam switchover is at like 6600 lol so obviously my gauges are completely off. anyone have any idea on what I can do?

Originally Posted by danwasdahl

Ok- Tach was at about 2-3 k with car off; about 3-4k
idling (didn't have my reading glasses last nite).

This morning
1) I opened the driver door, and left it open.
2) I turned off the security system by pushing the button
on the key fob in the usual fashion.
3) I pressed in the reset button on the right side of the steering column.
4) I turned the key on.

Needles swung below zero; dash showed software version, etc. Good.
I was holding the reset button in all this time.
After the dash display returned to normal, I released the button,
and turned the key off.
Now Tach is at 0 rpm with car off; maybe 800 or so when actually idling. Good.

It's been raining here. I'll test and see if the reset procedure fixed
what has appeared to me to be a late cam changover when it's dry outside.

Thanks guys
dan w

[charliex]

its possibly a bad cluster, its happened a few times.

[Randy Chase]

Have you tried disconnecting the battery?

[TimMullen]

Originally Posted by danielg

I've tried everything to reset my speedo/rpm. I follow instructions exactly. Anyone know why it doesn't work on my car?

Some people have had to do it many times before they get everything and the timing just right. Others have given up and disconnected the battery and reconnect it to do a reset...

A think one or two people have had to have the instrument cluster replaced...

[danielg]

havent tried disconnecting the battery...but i had the car sitting for a few weeks and the battery needed to be charged up/jumped, and the gauges were still off. your right...i think im going to try to disconnect the battery anyway. how long should i leave it off for? 5 min?

[danielg]

Originally Posted by TimMullen

Some people have had to do it many times before they get everything and the timing just right. Others have given up and disconnected the battery and reconnect it to do a reset...

A think one or two people have had to have the instrument cluster replaced...

yea i tried for like half hour over and over again. got out of the car..armed the alarm...un-armed, opened door and left it open, etc...

i hope it's not a bad cluster.

[Randy Chase]

Originally Posted by danielg

havent tried disconnecting the battery...but i had the car sitting for a few weeks and the battery needed to be charged up/jumped, and the gauges were still off. your right...i think im going to try to disconnect the battery anyway. how long should i leave it off for? 5 min?

The reset procedure has never worked for me. Disconnecting the battery does, and I only disconnect it for a few seconds.

I have something happening with the HID's initial surge causing the cluster to get confused.

[charliex]

Originally Posted by Randy Chase

I have something happening with the HID's initial surge causing the cluster to get confused.

has anyone tried a large audio supressor style capacitor on the power lines for the cluster for that ?

[Randy Chase]

Originally Posted by charliex

has anyone tried a large audio supressor style capacitor on the power lines for the cluster for that ?

I definitely need to do something, just been too lazy/busy and the symptoms are not that painful. Until last night.

Turned on HIDs, all cluster indicator lights lit up. Cluster lightbulbs went out. First time I had the illumination gone. I can live with the needles saying I am, as my wife mentioned this morning..."Dear... you seem to be driving 140mph down this residential road."

I was also considering putting some suppression on the power to the HIDs instead. And possibly replacing the cluster with another one to go with another ECU. Not sure about that direction right yet.

[charliex]

I'm curious if its a transient, noise or voltage drop problem, the former will neeed a conditioner arrangment, the latter two the capacitor.

a MOV probably isn't a good choice, since it'll expire or die on a big spike, some sort of discreet power conditioner would be better.