HELP!!! '92 fires but will not start!!!
 

Hey folks, please pardon my noobiness, but I am slam out of ideas as to where to go next concerning this problem. Let me start by saying that even though my Miata does not have a turbo (or any other aftermarket mods), I wanted to come to this forum for advice because the level of expertise that I have seen on these boards in my search for answers thus far completely buries some of the other forums that I've seen. That being said, here's the story:

About a month ago, I started her up (I don't drive her every day, she's a second car for me) after she had sat for a couple of weeks. Not unusual. She fired right up as always, and ran at an idle while I loaded a box into the passenger seat. As I was walking past the front end heading back to the drivers' seat, she died. Tried to start 'er up to no avail. Fire once and die, fire once and die, over and over again. This continues to this day, even with the following list of things that I have found to try and remedy the problem (almost all of which were found on this forum, btw):

1. Changed out the INJ relay in main block (several times)
2. New fuel pump and filter
3. Checked all associated fuses (st sig, room, engine)
4. Changed AFM

Here's what I know for sure right now, the fuel pump is not getting juice unless I jump the g and f/p terminals in the diag. box under the hood (or if I manually hold the flap inside the AFM) and turn the key on, which makes me want to think that it's a fuse or relay issue that I've missed, but damned if I know where. It's not a spark issue, because when I spray starting fluid into the intake she'll start and run smoothly for about 15 seconds before stalling. Could this all just be a bad COR? and if so, how in the world do you change that thing out? Thanks in advance for any advice you can give me.

Will it run if you ground the fuel pump?

What year car?

Uh, check the title of the thread?

It's a '92. Here's an update: Yesterday I managed to get 'er started, but would only idle rough. Any time I tried to give it gas, it died. At one point, with the key in the "on" position, I heard a humming coming from the throttle position sensor in the engine compartment, so I started it up again and tapped on the throttle body with a wrench. Each time I tapped it, the rpm's would smooth out for just a couple seconds, then back to rough. I continued alternately tapping and nudging the throttle, and low and behold, whatever was stuck inside the throttle body loosened up and the idle evened out and I could rev it with no problem. I'm going to clean it out with throttle body cleaner and see how that works. I am thinking that this may have been the problem from the very beginning, but she's got 207k miles on 'er and is probably happy to have all the new parts anyway. Thanks for responding!

Your AFM is bad. Since very few guys here have them on their cars anymore, do a search a Miata.net and they will help with troubleshooting. Hint: if you used a screwdriver to unplug the harness, you broke it. Cool kids fix them with a soldering iron or buy a new one.

Nope, AFM is functioning properly. Took it out and drove it around for about twenty minutes after getting it running and it ran flawlessly. Started on the first crank after shutting it off, too. Thanks for the advice, though.