Hello all,

This is my first post, I have a bit of knowledge about my 91 740, most of which came from this board when I was trying to diagnose a similar no-start problem which turned out to be the radio suppression relay about a year ago. So I know a bit and have a bit of mechanical knowledge, but am no expert.

So the basics of the problem are that the car isn't starting. It started not starting when warm. As in, drive to the grocery store, shop for a half-hour, come out and no start. Crank and crank and crank and nothin. Wait about 15-30 more minutes, and bang, no problem. So that went off and on for a few weeks until we couldn't get it to start at all.

I went and checked the diagnostic tester, swapped the RSR with the aux fan relay, did some other tinkering and finally got it to go (odd side note, I accidentally left the tester in hole six and it started, when I noticed it and pulled it out it began hesitating, so I quick put it back in to the hole and it ran fine again. Odd.)

But that was the last time it started for a while. More tinkering. The fault code was 223, (I think) which was IAC (I know) so I cleaned it up nice, but still nothing. I'm fairly certain it works because when I put it in test mode I can hear and feel the plunger click back and forth. It would also start a bit when I would spray in some starter fluid, but then would soon die and not re-start.

After a Saturday of wrestling, a friend suggested that I disconnect the battery to see if resetting the ECU would help. It's free and easy, he said, which sounded great. And lo and behold, After a few hours I reconnected the cable and it started like a champ and ran and ran (in the driveway). I tried a few times on Sunday, all of which were successful and easy. I started but didn't drive. Untill I got cocky and decided that I should go fill her up and take her for a spin. Started great in the driveway. <1 mile to the gas station. Off for a few minutes to fill up the tank...and crank--run for about a second--die, and then nothing.

So I pushed it to a spot in the lot, disconnected the battery (thinking hey, it worked last night) walked home, came back a few hours later, and nothing.

So that's the short (long) version of my troubles. Could this be a computer issue? It's a Bendix, which from what I've read here rarely have issues. Is there something else that's obvious that I'm overlooking? Is the success I had last night in disconnecting the negative wire on the battery to reset the computer a red herring? After it died at the fuel pump, the code again was for the IAC. But why would it start fine earlier today and show no codes?

Any help would be much appreciated.