Starts but won't run - A tale of woe

[LoganSquare]

Here's the short version: 1980 Spider 2000 FI. Car will start easily and run for 4 seconds, then dies. Revving it sometimes will keep it going for a few seconds longer, but not much.

Here's the long version: Bought car last year and it had a rough idle. My mechanic replaced a cracked rotor and adjusted the timing. Ran better but not perfect.

This year I checked the air filter (fine) and replaced the plugs, but no change in the idle.

A couple of weeks ago I took it to another mechanic (a non-fiat guy). He couldn't find parts locally and sent me home, telling me he'd like to replace the fuel pressure regulator. Good call. The diaphragm was burst and fuel was pouring out of the vacuum hose attachment.
I replaced the fuel pressure regulator with a new unit from Midwest Bayless, and the car ran well for one happy afternoon--about 20 miles. Then on the way home, it started dying at every stop sign. I stopped at a friends house and increased the idle to 1500rpm by turning the accelerator stop screw. This got me home without any more stalls.

The next time I went to start it, it would start but wouldn't stay running more than 4 seconds on its own. I can't keep it going more than 30 seconds even revving it. The fuel pressure regulator is not leaking fuel anymore.

Any suggestions for troubleshooting this? Like I said, it will start right up and run for a few seconds, but dies. Adjusting the idle up and down has no effect.
Any ideas?

[So Cal Mark]

check the intake boot for cracks. Setting the idle speed with the stop screw is not a good idea, that puts the throttle switch out of adjustment

[76was124]

The next time I went to start it, it would start but wouldn't stay running more than 4 seconds on its own.

Could be a bunch of things, but in general that "won't idle after four seconds " would make me think the cold start injector is not turning off, or there is a main injectors /fuel delivery problem.

Once it starts, pull the electrical connector off the cold start injector and see if that makes a difference. If not, and assuming you checked for air leaks as Mark said in the post above, read the fuel injection guide courtesy of forum member Mr. Brad Artigue at http://www.artigue.com/fiatcontent/Arti ... 124_MM.pdf

[4uall]

Had this exact same issue after bringing Fiona in for paint look on page 3

http://wwwe.fiatspider.com/f08/viewtopi ... ilit=funny

there is a ground wire which mounts to the tail light, 2 black wires, make sure they are hooked up, or the car will not run, it is the fuel pump ground. the reason i mention it is that you have a tail light removed.
i suggest you move that ground to an alternate location, as the tail light mounting bolt usually works loose, and it is in a area of high corrosion"

[LoganSquare]

Very good, thanks guys. I'll check the intake boot and the ground wire, and I'll review the fuel injection guide. I'll post if anything works. I'll probably post if it doesn't work. Here's hoping!

[DanD]

http://archive.mirafiori.com/show.php?fid=2&msg=94962

[kimu]

Any resolution to this thread?