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View Full Version : FTC 70 and 71 ??? Huh ?



J 98ta
June 13th, 2005, 06:50 AM
While logging at the drag track I have noticed the Fuel trim cell go to 70 or 71 for 1 frame and then back to normal. When it does this the ltrims will go crazy negative (~40%, but just for 1 frame). The 02's will read ~.300 for that frame as well, Then back to 'normal'for me at wot. (.880 to .920)

Ideas ? Would low voltage cause this ? I noticed the guage reading low, but I did not log voltage.

'J

Blacky
June 13th, 2005, 09:14 AM
Are you logging with black-box logging?

If so we have seen this behaviour on 98's when using Dynamic scan mode.
It may also happen when logging on laptops - but we have not seen any report of it yet. The laptop must process the logged data (write it to disk, display the gauges and charts etc) and that slight delay may be long enough to prevent the problem. Compared with the FlashScan unit which merely captures data to memory. Which means it has a much faster "turn around time" and sends the "next request" much sooner than a laptop.

If you are black-box logging, can you set the "Delay between dynamic frames" to 100ms. You can set that value in the window you use to reprogram the PIDs into the FlashScan cable. Then reprogram the PIDs into the FlashScan cable.

If you are using a laptop, can you set the Properties->Advanced->Throttle to 100ms.

Those changes affect ALL comms with the FlashScan cable so you will see a slight slowdown in the comms speed.
Basically it adheres to the 1999 SAE recommendations that: "No message shall be transmitted by the Scan Tool within 100ms of the previous message".

In 2003 the SAE updated that recommendation to: "A Scan Tool may send a message within 100ms of the previous message if all responses have been received".

So EFILive can be configured to work both ways.

Regards
Paul

J 98ta
June 13th, 2005, 12:56 PM
Paul,

Thanks for the quick and informative response. I am using black box for logging. I will set it to those settings next time out.

'J