1991 FC Vert NA - engine error codes
 

So… I recently found myself (yesterday) in the possession of a 1991 automatic non-turbo RX7 convertible. This is my first foray into the world of rotary engines and honestly this is my first sort of resto-mod I have ever tried. I bought it for my son (16) and I to have something to work on together in these last couple of years before he heads off to college and begins his own life. I was sitting in the hospital with my mother who is being discharges to hospice and while perusing facebook marketplace I came across a car that spoke to me. I had no intention of purchasing one prior, but it just looked so dang cool and that it was a convertible just sort of put me over the top. I started thinking about my family and things that my son and I cold do to become closer and it just seemed like a natural fit. I contacted the seller and after minimal negotiation I am the proud owner of a bright red RX7 convertible with a loud as heck cat back exhaust! My wife is as thrilled as you can imagine but my son and daughter are on board so she was out voted…for the time being 😊

I don't know much about the car’s history, but the previous owner claimed to have owned it for the past 8 years. It currently has 84814 miles and is in pretty rough shape.

The good: The engine runs well and sounds great. The body is virtually rust free and only a few minor dings and bruises. Original paint is in surprisingly good condition. Fired right up in the cold Michigan weather and idled and revved well. The price was such that even with the ugly below I am still comfortable that I got a good deal on the car and plan on enjoying the restoration effort.

The Bad: Top has some tears, and the fiberglass body kit is beat to heck, pretty much all components are cracked but surprisingly the damage does not seem to make it to the metal panels. Interior is filthy and lots of missing/cracked plastic pieces. Broken switches and the center console is loose but the automatic top does work with come coaxing of the switch,

The Ugly: currently in limp mode. Car will not shift out of 1st gear also has a broken 5th or 6th port actuator

The ugly is why I am here!

The engine ECU threw the following codes

8, 10, 33

• 08 - Airflow Meter (AFM) - Basic Fuel Injection and fixed timing (Cripple mode)
• 10 - Intake Air Thermosensor (AFM) - Intake air fixed at 68F
• 33 - Solenoid, Port Air Valve

Seems like the first 2 error codes 8, and 10, would be solved by replacing the MAF/AFM whatever it is called. would this be a safe assumption?
The last code I would assume relates to the broken component of the 6th (I believe) port actuator valve. I am still trying to find out what exactly the actuator connects to is called. pictures.attacehd.

Any thoughts on how to repair the MAF or does it require a new or functional used component replacement?

Pictures of the port actuator below.

thank to ANYONE who may be able to assist! SO far I am 0 for 2 on questions in the newb section lol. Thanks again

https://cimg5.ibsrv.net/gimg/www.rx7...d6423e6711.jpg
bad one
https://cimg6.ibsrv.net/gimg/www.rx7...6b39bb5a00.jpg
good one

Ya id inspect the wiring to the air flow meter and if it looks ok replace it. The fsm.has a procedure for testing thr afm with a multimeter if you have one of those.

The other code is not related to that broken actuator. I beleive the port air solenoid is the one on the air control valve and is for emissions

Foxed.ca has all the repair manuals should be able to find section with each component and how to test them

I see you’re in Michigan. DM me, I’m converting mine to Carbureted and have an extra LIM with working 5/6 ports and a good MAF I’d part with cheap.

Thank you for the reply.

First, yes I downloaded all of the FSMs and other documents from them. I just wish there was an OCR searchable document. I thought I was on to something and merged all 2316 pages and tried to OCR convert it using PDF Exchange Editor but so many of the diagrams turned it in to garbledy guck, completely useless,

My main focus right now are the codes that are causing limp mode or fail-safe operation. code 33

I will be testing the AMF tomorrow.

I took a picture of the connector and there appears to be a loose wire but it does not appear to have a slot in the connector.. .any idea what it would be pic below

https://cimg1.ibsrv.net/gimg/www.rx7...101792f0c9.jpg
what is this loose unsheathed wire?

So I tested the AFM and got the following results
E2->Vs 0 resistance
E2->Vc 287.3
E2->THA 0 at approx 32 degrees and again 0 at 72deg room temp after I brought it inside to test everything else again

I am thusly going to assume my AFM is dead.

Thanks to lespaul166 hopefully I will be getting an operational one Tuesday evening and I will be able to drive the car.

pic of test specs below for reference


https://cimg1.ibsrv.net/gimg/www.rx7...7b3832c6a8.png
AFM test specs

That's a shield wire for the green wire. If you look at the wiring diagram, than you will notice a dashed line next to the green wire. That dashed line represents a shield wire. That shield wire isn't supposed to be attached to anything on that end. The shield is grounded on the other end of the cable. The shield serves to reduce electrical noise from adjacent wires from affecting the signal in the green wire.

thanks for clarifying that for me. Just wanted to be sure I wasn’t missing something elementary. And now I know about shield wires 👍


As I said elsewhere this is my first dive into restoring/modding an older car. The learning curve is steep but I am slowly picking it up. I am sure I’ll screw the pooch a few times here and there but the best way to learn is to do!

thanks again hot_dog!