Ecm #12584052 Mefi-4b used by Painless wiring

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Jsflyrv
Posts: 2
Joined: Sun Jul 13, 2014 9:38 pm

Ecm #12584052 Mefi-4b used by Painless wiring

Post by Jsflyrv »

If this is not the correct forum for me to post this question in please help point me in the right direction.

I have a 1969 Camaro with a 1994 Corvette LT1 engine. It has a Delphi Painless perfect ECM Mefi-4 #12584052. I was using the InGenius software for tuning which worked well but was limited. I bought Mefiburn scan and tune software which required clearing the ecm and loading a bin from mefiburn. Using TunerPro V5 with mefi-4b10.xdf and a bin file from Mefiburn called LT1perfect65105-4b. It works great and I can set all he commands I need. My problem is I am not sure what commands controls the A/C when I turn on the A/C at engine idle it wants to lower the rpm so much it will stop the engine. Any ideas?
cbernhardt
Posts: 95
Joined: Fri Apr 18, 2008 5:19 am

Post by cbernhardt »

I have the MEFIBurn scan and tune software for my RamJet 350 engine with the MEFI4a controller. I'm not certain but I think the only difference between the 4a and 4b is the CAN bus interface. Unfortunately I do not think there is a specific setting to increase idle for a/c, but you should contact Bob at OBD Diagnostics to be certain.

Other than just increasing the idle speed you might try changing the following settings:
"Open loop fuel control when throttle closed"
"Always use BLM 0 when throttle closed"

Also, with the A/C off, does your engine ever just die when coming down to idle after a long run on the highway, like when coming to a stop at the end of an off ramp? My RamJet did this and the solution was to open up the throttle plate just slightly. Don't know if that would help on your engine though.

Charles
Jsflyrv
Posts: 2
Joined: Sun Jul 13, 2014 9:38 pm

Post by Jsflyrv »

cbernhardt wrote:I have the MEFIBurn scan and tune software for my RamJet 350 engine with the MEFI4a controller. I'm not certain but I think the only difference between the 4a and 4b is the CAN bus interface. Unfortunately I do not think there is a specific setting to increase idle for a/c, but you should contact Bob at OBD Diagnostics to be certain.

Other than just increasing the idle speed you might try changing the following settings:
"Open loop fuel control when throttle closed"
"Always use BLM 0 when throttle closed"

Also, with the A/C off, does your engine ever just die when coming down to idle after a long run on the highway, like when coming to a stop at the end of an off ramp? My RamJet did this and the solution was to open up the throttle plate just slightly. Don't know if that would help on your engine though.

Charles
Thanks Charles for the tips I will give them a try, I do have a call in to Bob waiting for a reply. Well let you know how it goes.
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