Incorrect rpm values

Discuss issues and tuning software like DTASWin, E-Race, MegaLogViewer(DTA), etc. Also post archive versions of firmware.
nikfruit
Posts: 54
Joined: Thu Sep 22, 2011 6:42 pm
ECU Model: S80 Pro
Firmware Version: 71
Location: Greece
Contact:

Incorrect rpm values

Post by nikfruit »

Several times I am taking incorrect values from datalog. Does anyone know of resulting.
I cite below an example.
Attachments
2012-12-24 00.34.01.png
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Incorrect rpm values

Post by stevieturbo »

Most likely electrical interference somewhere causing a spike on the crank signal.

If you cannot feel it, and it is not causing a fuel or timing to alter, then probably not much to worry about.

Any HT leads near the crank wiring ? crank wiring shielded etc ?

Might be interesting to do a log at 100hz, to see if it shows up more ?

Are you getting many rejected pulses etc ?
Roverdose
Posts: 318
Joined: Tue Aug 09, 2011 2:54 pm
ECU Model: S80 Pro
Distributor: Roverdose
Location: Stevenage
Contact:

Re: Incorrect rpm values

Post by Roverdose »

did you hit the rev limiter?

Drew
nikfruit
Posts: 54
Joined: Thu Sep 22, 2011 6:42 pm
ECU Model: S80 Pro
Firmware Version: 71
Location: Greece
Contact:

Re: Incorrect rpm values

Post by nikfruit »

No i didn't hit the limiter because is up to 8400rpm but while studying the log last days i guess that issue occur from some slip.
nikfruit
Posts: 54
Joined: Thu Sep 22, 2011 6:42 pm
ECU Model: S80 Pro
Firmware Version: 71
Location: Greece
Contact:

Re: Incorrect rpm values

Post by nikfruit »

Stevie my log sample rate is set at 100hz think so, i confirm it.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Incorrect rpm values

Post by stevieturbo »

It is not wheel slip, it is a spurious reading.

Again, are you getting any crank signal errors, rejected crank pulses etc ?
nikfruit
Posts: 54
Joined: Thu Sep 22, 2011 6:42 pm
ECU Model: S80 Pro
Firmware Version: 71
Location: Greece
Contact:

Re: Incorrect rpm values

Post by nikfruit »

This are the rejected pulses are they important.?
Attachments
2012-12-28 22.55.34.png
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Incorrect rpm values

Post by stevieturbo »

yes and no.

It basically means the ecu has not received correct readings from the crank trigger. If this happens, it basically ignores the error and lets the engine continue as it does understand it is wrong.

Looks like you've had a few crank and cam errors though ? Ideally this value should be as low as possible, ie zero.

So it could be a sensor problem, wiring, air gap etc etc.

There also look to be a large number of resets on the top right ? Although, how long as it been since you reset these ? If it has been a long time, these numbers may actually be relatively small.

or...and I see you're on an S80. How old is your unit, and do you have the metal case itself earthed ?
nikfruit
Posts: 54
Joined: Thu Sep 22, 2011 6:42 pm
ECU Model: S80 Pro
Firmware Version: 71
Location: Greece
Contact:

Re: Incorrect rpm values

Post by nikfruit »

I think the time from the latest reset is up to 4-6 months, the s80's age is about 12 months, and the metal case is self earted.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Incorrect rpm values

Post by stevieturbo »

The numbers really arent high at all then. Ignoring the log for a second...are you actually feeling anything odd happen with the engine when these high rpm numbers appear ?

Must admit, Ive never actually logged at 100hz myself, so maybe an odd spurious reading isnt so strange. Might try over the next few days if I can get a dry day.
Post Reply