I just took a video of me starting my '87 NA warm. It struggles for a second, revs up to about 1500, then immediately dies. I did not touch the gas at all. Please watch the video and give me some thoughts. A few others potentially relevant pieces of information:
- The ECU gives me the air flow sensor error code.
- You can see on the video that the oil pressure reads very low. I realize this is not good but I don't know if it's directly related to what you'll see in the video
- When the engine is cold, it lasts about 5 minutes but the idle is very erratic. At first it hold steady at about 2500 then after a few minutes varies randomly between 1000 and 2000

Here's the video link:
http://www.youtube.com/watch?v=nJqbtS3xEms

 

Replace the AFM. I have a bad one that will make idle extremely rough just like that. Not to mention, you're getting the trouble code as well.

 

what is the afm?

 

Common abrevations sticky thread: https://www.rx7club.com/showthread.php?t=782434

AFM = Air Flow Meter.

 

Make sure you don't have some vacuum leak somewhere.

 

I see that Mazdatrix sells the airflow meter for about $900. Is there a cheaper alternative part available?

Would a vacuum leak cause the ECU to give me the AFM error code even if the AFM itself was functioning properly?

 

Get some more posts under your belt, then visit the classified section. I've never seen a vaccum leak cause an AFM error code. These are very simple EFI systems, with very limited diagnostics. The ECU pretty much just looks for appropriate voltage feedback from sensors, and if it is out of range, it throws a code. A vacuum leak would just cause the introduction of additional air into the engine that the ECU doesn't know about.

 

Will do. Thanks for the info! I'll post a video of what it does on a cold start when I get home tonight

 

it looks like there might be a vacuum leak

 

I'll be checking for vacuum leaks ASAP

Will an AFM from any other models fit on my NA S4?