This vehicle has 150K miles on it and has ran fine up to a few months ago. Engine began to run rough and blew clouds of black smoke out the exhaust. It would eventually die and would be very difficult to restart unless it cooled down. Sounded like a classic O2 sensor problem so the the O2 sensor was changed. Engine now starts and runs good but a new problem now exists. After the engine warms up it will continue to run okay but if the engine was shut off for any reason it would be impossible to restart until it cooled down. The routine can be repeated over and over. Last year the cat converter, fuel pump and filter was replaced. Recently the spark plugs, wires, cap and rotor were replaced. The spark hasn't been checked so far when hot. Fuel does't seem to be the problem since it restarts after it cools. Is there any temp sensors that can be causing a problem? Is there a ignition tester available that doesn't cost more than the truck?

I'd check the easy thing first -- you said the fuel filter was changed. How about checking to see if the fuel line is now touching something hot? If so, it could vaporize the fuel in the line and vapor lock until it cools down. Check it out before you spend....

I'd check the easy thing first -- you said the fuel filter was changed. How about checking to see if the fuel line is now touching something hot? If so, it could vaporize the fuel in the line and vapor lock until it cools down. Check it out before you spend....

Hello fredjacksonsan,
The fuel filter and fuel pump were changed long before there was a hard starting problem. The filter being located along frame rails under truck bed and away from anything hot kinda eliminates the vaporization idea. When the truck did developed a problem it began running very rich all of a sudden. Since I had a similar problem with an old Dodge Shadow that had a bad oxygen sensor and this is what was changed on the Dakota. It solved the running rich problem but now it will run fine as long as you don't turn it off. If you turn it off and try to restart right away it will just turn over without firing. It then will have to sit for a while until it cools off before it will restart. It sounds temp related, maybe a bad temp sensor or ignition coil?

Yeah, sounds like a sensor problem, the electronics must be reading something wrong. Sorry I don't know exactly what it could be... might be time to take it to the dealer to hook it up....

Yeah, sounds like a sensor problem, the electronics must be reading something wrong. Sorry I don't know exactly what it could be... might be time to take it to the dealer to hook it up....

Up date on situation; the igition coil was replaced with a new one but problem hasn't changed. Engine will start fine cold and run continuously even when hot but once engine is shut down while hot it will not restart.

Saw on the Ram Truck forum, some folks have had problems with their fuel pump overheating, once they replaced it their problem went away. Similari situation to yours, dies when hot but runs fine when cooler.

Check to see if your fuel pump is running when you switch on the ignition.

Just for the hell of it I would replace the temperature senser should be somewere around the thermostat housing. I have a 93 F150, since Ive owned it .it ran rich no codes. I replaced the o2 senser twice. Each time it seemed better for a short time afterwards. Not for long then it would start running rich again. The truck would blow out black smoke when you got on it. Finally I tried the Temp senser for half the price of a o2 senser and bingo it was fixed. My truck would run good cold when up to operating temperature it start to run rough. It would act like running with the choke on if it were carburated.
I don`t know if this is your fix, but in my case it was $20.00 well spent. I took my truck to a mechanic first he replaced the o2. he couldn`t find any other problems. I change the o2 the second time. After some time and frustration I gambled on the temp and won. No codes from the ECM.
Yours may actually be flooding on warm start up.

Thanks to all who tried to help with this finicky Dodge truck. My neighbor who actually owns the truck finally took the thing to a dealer and had them run a diagnostic test on everything. A bunch of codes came up and led then to a faulty CO sensor that had shorted out in a wire bundle behind the distributor. This short also burned the wiring to the dash fan motor causing it to go out. After changing the CO sensor and burned wiring truck runs fine once again. Thanks to all and if this info will help someone then it's worth the effort to post.

Thanks for posting the results.