If they want to DIY and come to forums for help/guidance/learn how to do things for themselves. Yes.

I am here for personal not professional. Same with the 2 other forums I am a part of. Advice/help is free.

When I am working I am for professional, so my knowledge/help/tools are not free.

Thanks BUP for his knowledge and helping out with my issues.

Here's what no one saw:
IAC Duty Cycle.... 0.00 % with idle at 690RPM.
My guess at 0% it may have a vacuum leak and can't regulate idle to spec-650

I'm going out this weekend and log data(Rinda) at various RPM as BUP requested and post.
Also noticed this data at idle and not sure if it's spec or not: Spark Advance... -7.75 DEG

Will update and this is a great learning experience. BTW, my background I was a VW master tech for 40+ years before retiring...

Attached is data recorded with Rinda Diacom at various RPM including cold not running and cold idle. screen shot photos

You are welcome your first scan report stood out like a sore thumb and now I see you have issues actually more than one form scanning per how I asked you to do. This shows a more indepth of whats going on correctly and the incorrectly for a jist.

So with that said who wants to take a stab at it ?


So lets ask a question first instead of me posting whats wrong here, A good learning experience for whomever or however

On efi / mpi engines what is the most important thing that is needed and be properly working from the get go ???

what is the start and focal point of an efi system ??

I was paying attention in class.
Professor BUP has taught us that a fully charged battery is paramount to proper EFI engine operation.
Mr. Woodchuck needs to charge his battery or replace it if defective.

Not sure if I agree with your comment. Real world a fully charged battery is 12.6V. With key on and engine not running the ECM is reporting 12.38v. At idle it's 13.68v and all running voltages above idle are over 14v. Mercury manual states 13.9-14-7 at alternator, but I think it's well in spec as what the ECM sees. BTW, battery is new this spring and tests good.

Thiis is why I run carb and distributor in my boat. I'm not at all up on efi, even though I work counter and service sales at a car shop. My diag techs tell me what is broken and I pass it on.
C'mon BUP I wanna know what you see, and how you I can see it.

correct it all starts at the battery with voltage. Many think it all starts at the ecm - nope VOLTAGE

NH is correct for problem number one. A fully charged battery is 12.75 volts at 12.3 that is only a 65 % charged battery.. So for problem one - weak battery or bad cell - or something causing a voltage drop. Take a closer look at the charging rate at 4 rpms it starts to fall compared to other voltage reading vs RPMS. so at 5 K what is battery voltage ?

Here is a laymens state of charge for batteries.

prob 2 is what ? it stands out like a bullseye