My buddies 82 coupe with an efi 302 swaped in it has never ran right since it started up.. It has an A9L computer. how do you check to see if its throwing codes?
It plugged in to a connector on the drivers side by the firewall. I forget the exact sequence, but the instructions were really clear. There is a way to to it with a light bulb and some wire too if you want.
Dump the codes and see what the computer says is wrong…
Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.
IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.
Puzzle time . . . while it has been a while, I have used the method referred to in this thread previously but I am having trouble getting it to work now. I hook the jumper lead up as described and hook the analog meter up to the battery and the output pin but when the meter is hooked up it reads 12 volts as soon as it is connected (don't remeber this happening before). Anyway, I go to the KOEO tests and the needle never moves off of 12 volts (no sweeping). Anyone have an idea as to why.
The symptom the cars is exhibiting is when I push in the clutch to downshift and come to a stop in either hunts for idle or usually shuts off.
The car is a 1991 5.0 with a recently swapped out used engine and I did have to replace the computer when I did that.