hard starting when hot

[randeeb1]

I have a 1980 2000 spider FI,starts and run great when cold....once warmed up it may stall or if you shut it off you have too crank and crank then it will start...it bucks..skips and feels like cutting back in forth between 2 3 and 4 cyl.....temp will always be just bellow 190 degrees...spark plugs are very light grey/white..and sometimes smells very rich...I have replaced coil...cap...rotor...plug wires..I'm not sure I'm in the right area !

[rlux4]

Does it act this way consistently? If so, then your problem is temperature related and I would suspect the temp. sensor in the coolant "T". It is the most critical sensor in the system, and if it goes bad the engine will either not run, or run very poorly, which sounds like what you're experiencing.
Ron

[randeeb1]

no its not consistently..but happening more and more .....is there a wy to check that coolant sensor ?? thank you !

[rlux4]

Yes. You can check the resistance of the sensor. Unplug the ECU and connect an ohmeter between terminal 13 and ground, the meter should read: 7,000 to 12,000 ohms at 14° F, 2,000 to 3,000 ohms at 68° F, and 250 to 400 ohms at 176° F. A little trick you could use is to get a resistor in the range of 300 ohms and plug it in place of the connector for the temp sensor. This value tells the ECU that your car is at normal operating temperature. If it clears up the problem, you have a bad sensor.
A good manual to get is Brad Artigue's Fiat 124 Engine Maintenance and Modification . It has a section on the Bosch L-Jetronic FI that has this information along with a good explanation of the system and other diagnosing tips. Download it here: http://www.artigue.com/?page_id=30
Ron

[So Cal Mark]

I've never seen a failed sensor act intermittenly, I'd look closely at the connector to the ect, but since it runs fine cold you probably have another issue