Dies when warm, What the hell???

[skippygozoom]

I am stumped on this one, along with a few pretty good local mechanics.

The car is an '85 dodge diplomat. Starts up fine (runs a little ruff, but keeps running) I can drive it for about 5-15 minutes and about so many miles and it will start to act like it is lossing fuel or something. It doesnt die right away it just stops responding to throttle, like im not getting fuel. Then it will die.
I can start it up again right away, but am then only able to drive about a block or so and it dies again.
I have gone(as far as I can think) completly through the fuel system already. Drained fuel tank, flushed all lines with air, new fuel filter and pump and totally reworked carburetor.
After all that I still have the same issue.

Sorry for writing a book here, just trying to give all info.

Absolutely Any and All hepl is very much appreciated! Thanks for reading.

[MagicRat]

Okay, lets assume you have checked to see the choke actually opens up properly and the choke pull-off works. Also, the carb float bowl is clean and no debris is blocking the main jet circuit.

If that's all okay then IMO: bad ignition coil. Replace it with a new one.

This happened on two cars of mine plus my boat (with a GM 2.9 liter 4 cyl stern drive). The coil works ok when cold, but develops too much internal resistance when hot, leading to a weak spark.

I swear, the symptoms mimic fuel system issues, so I came to the same conclusion you did, at first.

[skippygozoom]

Really?!
All things you assumed are true. All with carb is good.

I will definatly check/replace it then. Thank you for your reply.

Also what are your or anybodys thoughts on it being a blocked catalytic converter/causing to much back pressure or something. this was suggested to me by a friend but i dont know if that could be making it die like it does...
Thoughts???
Thanks again for the help.

[MagicRat]

Originally Posted by skippygozoom

Really?!

Also what are your or anybodys thoughts on it being a blocked catalytic converter/causing to much back pressure or something. this was suggested to me by a friend but i dont know if that could be making it die like it does...

Blocked converters would affect performance uniformly, whether the engine was hot or cold.

[bobss396]

You more than likely have an electrical issue there. I would look at the coil and anything under the distributor cap as being suspect.

Bob