Things that cause an Early Rev limit. - Too soon Junior

[dan10101]

Other that the standard fuel cut rev limiter, what are some things/sensors that can cause an earlier than expected rev limit? The dyno sheet that came with the car shows it revving to 6800 but it cuts out at 5200 in 1st gear.

Coolant Sensor - engine thinks it's cold. (my OBDII says it 190) Are there 2 coolant sensors?
VSS - Speed says it's too fast when it isn't
Gear based speed limiter (same as above?)

Here's what I'm working on.
2004 LS6 crammed into a Porsche 914 4 speed manual.
2001 Camaro 411 ECM.
Speed Density Tune, (no MAF)

[stew86MCSS396]

Idk if it has anything to do with this. I like to wind out that first gear but I don't own anything that has a 3.06 1st gear.
http://www.gearhead-efi.com/Fuel-Inj...r-Fuel-Cut-Off

[dan10101]

That's the kind of thing I'm looking for. Thanks...

But with my trans being a manual 1978 Porsche transaxle, I don't know how the computer would know how fast I'm going. Sure I have a speedometer, but I'm pretty sure it's analog. Still, I'll look for that in the computer to see what it says. It makes the most sense. Maybe it calculates it based on gear ratios and rpm.

[1project2many]

Vehicle speed is generally one of the values which can trigger the ecm to cut fuel. If the vehicle speed is reported incorrectly then you may need to increase the maximum speed allowed in the calibration. The maximum speed allowed is 255mph so if the reported speed is dramatically off you may have to find a way to change the speed signal so it is reported correctly.

[dan10101]

Thanks, I need to research how the speedo is driven, maybe they are tapping into it somehow.
I still suspect that a sensor/sender is causing this problem since it all worked at one time.

[1project2many]

I still suspect that a sensor/sender is causing this problem since it all worked at one time.

Hmmm... has it ever worked for you? Is it possible the speed sensor was disconnected for the dyno run?