Today, I started my 9A, with the 0-320 engine and constant speed prop. The AFS 5600 EFIS showed a MAP of “27” when I turned on the master switch. It immediately went to “- -“ as soon as I started the engine. In addition, the amp meter jumped up in the red to “49”! I shut it down, checked the #3 cylinder connection (no issue) and the AFS sensor wiring. Did not find any loose connections or connector pins missing or broken. Does anyone have any suggestions or history with this issue? I will be grounded until I can come up with a solution. There are no wrong suggestions. Hope you can help.
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MAP issue
- Thread starter 9Abuilder
- Start date
Thank you, Ir172, for your reply.
I live in SE Arizona. The field elevation is 4800’. Checked the 60 amp shunt. Nothing loose. Checked the connections in the back of the EFIS. Nothing loose. Looked over the Plane Power alternator, but could not see anything obvious. The amp meter on the AFS 5600 jumped up to +49 as soon as the engine started. Had not turned on any lighting. Only the single com. radio, Dynon D-6, AOA, and intercom lit up at this point. Normally, I see a “-3” draw a on the meter.
I live in SE Arizona. The field elevation is 4800’. Checked the 60 amp shunt. Nothing loose. Checked the connections in the back of the EFIS. Nothing loose. Looked over the Plane Power alternator, but could not see anything obvious. The amp meter on the AFS 5600 jumped up to +49 as soon as the engine started. Had not turned on any lighting. Only the single com. radio, Dynon D-6, AOA, and intercom lit up at this point. Normally, I see a “-3” draw a on the meter.
A MAP of 27 sounds about right for 5K feet with the engine off. Can't say why it is going to -- after startup. Sensor problem or wiring problem would be my first guess. Do you have a lithium battery. If the battery is discharged a good bit, it is not uncommon for the alternator to go near max output after startup. This is typical with a lithium battery. After a simple start up drain it will go to max output for a very short period, due to the low internal resistance.
Larry
Larry,
Thanks, again for your help. I don’t have a lithium battery, but I did discover the battery terminals were not as tight as they could be. After tightening the terminals, I started the engine. The MAP read “27”. The amp started at “30”. I taxied around for 15 minutes and the amp reading slowly went down to “7” before I shut the engine down. Don’t know for sure if that was the issue for both the MAP and the amp meter, but they both appear to be working again. Will go back out tomorrow and check to see if things changed for the better. Will keep you posted.
Thanks, again, Larry for your help.
Thanks, again for your help. I don’t have a lithium battery, but I did discover the battery terminals were not as tight as they could be. After tightening the terminals, I started the engine. The MAP read “27”. The amp started at “30”. I taxied around for 15 minutes and the amp reading slowly went down to “7” before I shut the engine down. Don’t know for sure if that was the issue for both the MAP and the amp meter, but they both appear to be working again. Will go back out tomorrow and check to see if things changed for the better. Will keep you posted.
Thanks, again, Larry for your help.
