Cleaning up my TPS signal.

[devastator]

I would like some advice on cleaning up the TPS signal to my MS2 controller. I have had to set my "TPS Averaging Lag Factor", in MT, to 20 in order to keep random accel events from occurring. I have left the sample rate at 25. I think this is causing me some unusual TPSDOT values in the Accel Wizard. If I stomp the pedal to the floor as fast as I can, I get values ranging from 12 to 100. This is with and without the engine running. I adjust my TPS only accel table to use 40 as a maximum pedal speed, and then MS gets a 100, 21, 45, or other speed signal, causing incorrect accel fuel amounts.
Should I run a shielded wire to the TPS? Where should I ground the TPS wire shielding to if I do add it? Should I replace the TPS sensor? Any other suggestions?
Thanks in advance.
Dev

[devastator]

Anyone?

[drholl]

Hi Dev, I've been on a business trip for quite awhile. Sorry. But the TPS signal appears erratic to me. If I hit the "Go" pedal about the same each time , it responds about the same each time. So it could be just an erratic switch, but I have also moved my sample rate under "General settings" to a higher value with good success. Mine is up to 30. The Mapdot and TPS dot steadied down quite a bit.
I hope this helps, as you've helped me out a bunch in the past.
Thanks
Holl

[devastator]

Thanks Holl,
So I might just have a bad TPS sensor you think? I have my sample rate at 25 and my TPS Averaging Lag Factor at 20. I was testing my accel by logging an accel event, reading the datalog tpsdot values, then changing the accel wizard, and repeating. More fuel, less fuel, and several tpsdot settings all amounted to the same thing-only getting the correct accel fuel at "slower" pedal speeds, and varying tpsdot "fast" values. I can try changing the sample rate. Is there any other way I can clean up the signal?

I hope this helps, as you've helped me out a bunch in the past.

Happy to help.

[drholl]

My lag factors are at 50 & 60 and sample rate is 30.
Works well.

Is there any other way I can clean up the signal?

None that I know of, but I'm not an expert.
Give these a try and keep us posted.

"The sand dunes and Oldsmobile must be conquered."
I ride a Yamaha Big Wheel out there.
Holl

[devastator]

What's a Yamaha big wheel? I'm over at Ogilby when I go.
If I get time this weekend, I'll try those changes.

[drholl]

BTW, I am going to be Squirting my 59 Corvette using a 59 mechanical Vette FI unit. I'll be using MAP sensing instead of TPS. I'm still a couple months away from the install day, but who knows, maybe MAP is the way to go.
Holl

[devastator]

I've tried MAP accel several times, but it does not work on my sandrail at all. My MAP signal bounces around like a basketball, so I have tried setting the ACCEL to only work under extreme MAP change, (like when the turbo kicks in), and it didn't work out at all. I'm back to, and likely stuck with, TPS accel only. Maybe I should run shielded wires to the sensor? Maybe add a ground somewhere?
Wiring+me=disaster.

[drholl]

On MAP sensing, run the lag factors up to 70 and the sample rate up to 80 or so. That'll smooth things out quite a bit.
With MAP sensing not much AE is needed, actually very small.
What are your values for AE, both TPS and MAP?

Thanks Holl

[devastator]

Here is one of my more recent MSQ's for you to peruse. I've never tried MAP sample rates higher than 25. I tried TPS sample rates higher than 25, however, and started getting random accel events. Maybe I just have the wrong combination of Lag factors, Sample rates, and TPS threshold?