I've discovered a really strange issue with TunerPro RT and Datamaster: They do NOT report agreeing MAP/vacuum readings on my $8D 730-based setup. No wonder I'm having trouble getting my VE tables right.....

I've confrimed this several times, but TP typically reports 8-10 Kpa less than Datamaster under the same conditions. I can best show this at idle with a totally warmed up motor. I can log with DM, then switch to TP, back to DM, then back to TP - all without ever shutting off the motor seeing any appreciable engine temperature or RPM changes. TP will report 34 -36 KPa at this idle and DM will report 43-45. I think I've seen fairly similar differences at highway cruise speeds, but can not confirm these since it's hard to switch back and forth while driving at 60-70 MPH.....

Has anyone else seen or noticed anything like this before? I wonder if my ECU file for TP-RT is incorrect somehow. I'm using one labelled Super_8dm2, which I got from Mark's site, but maybe it's different or off somehow?

Anyone have a 3rd product or method I can use to see which one is correct? Or maybe a different "correct" TP ECU file to see if that's my problem? Both products have their advantages, but I see no reason why they should have different values for the same "conditions".

What am I missing?

 

Try a mechanical vac gauge at idle.

 

I can agree with the tunerpro definition being different. I had to make a change in the tunerpro aldl definition to get it to agree with datamaster and 2 vacuum gauges as well as my Genesis scanner.

 

What change did you have to make? Would you be willing to share your ECU file with a fellow Texan? Pretty please?

 

I'll get it to you tonight once I get my laptop charged.

 

Thanks!!! My e-mail is vern.walls@parsons.com

 

There are 2 main MAP formulas used.
MAP kpa = (raw byte) * 0.3125 + 20
MAP kpa = (raw byte) * 0.369 + 10.415
So the range of the 1st formula is 20-99.7kpa and the 2nd is 10.415-104.5kpa.
Is this the problem or is there something else that is conflicting?

 

Hmmm, neither of those formulas match the ECU I have (version 1.01). It's using a factor of .392157 and has zero for the offset.

I was lucky enough to have a 1.02 version just e-mailed to me one of our members (Thanks, eric305TPI!!!). It just shows the Raw MAP value. Which formula would you recommend using for a 91 with $8D (speed density) on a 730?

 

Here is where I have it located if anyone else wants it.

http://home.houston.rr.com/lisfamily/1227730.ads

If anyone sees something out of wack PLEASE let me know.

 

That first formula, which is what Eric has in the above ADS file, solved the discrepancies.

THANKS, EVERYONE!!!!