81 spider wants to stall after a decent long drive

[ExpertTees]

Hello Everyone,
First time to use Fiatspider.com and seems to be awesome. I have a 1981 spider 2000 in great shape. She only has just over 36,000 miles on her. Recently when I acquired the car I gave her some basic tune up. New plugs, air filter, o2 sensor, and basically a whole new fuel system. But just untill about a month ago she will want to stall on me when I come to an idle after about a 30 min drive or so. She'll sputter then i will have to pull over and wait 5 min and i can go for another 30. But as i see in idle the temp will fluctuate about 35 to 40 degrees. So lets say 180 degrees driving then 220 on idle. So i really dont know if these are to seperate problems or is the temperature rise causing the vehicle to want to stall. It almost sounds like she is starving for fuel but new fuel filter, pump and blowing out the lines should have cured that problem then. I am a broke college kid so I am hoping it is a minor fix. Im spending my money on this other stuff that probably did not need to be changed to fix this minor problem. Pretty soon it will be a brand new fiat. Any suggestions. Thanks, Mike

[So Cal Mark]

the coolant temp sensor on the water tee is the most important input to the computer, fuel mixture is controlled by that reading. It's very common for the connector to fit loosely, causing a poor reading which in turn could cause a very lean condition.
Fluctuating engine temp is not normal, and rapid fluctuation usually means air in the system

[ExpertTees]

Hey, I appreciate the quick reply, I will try to do that asap when I come up with a few bucks. Thanks again, Mike

[ExpertTees]

Sorry to bother again. But I just replaced the temp sensor and also put a tee on the top hose to let air out and fill from there and I still have the same problems. I was told it could be the coil breaking down, throttle pos sensor, or that complicated mechanism on top of the air filter. Any Ideas. Do any of these sound familier? thanks Mike

[narfire]

I liked Marks suggestion. I found,if you have the black hood liner, that if it sagged,it did loosen the sensor at the "T" and the car ran like poo.
Make sure the sensor connectors are all on tight. one under the intake manifold. Injectors ect.
The FI system once sorted, can give great reliability and good performance.

[So Cal Mark]

I didn't suggest replacing the temp sensor without testing it, but merely checking the connector for proper fit. Broken connectors are common and easily replaced. Try wiggling the connector to see if the engine fluctuates. The air flow sensor can cause trouble, if the flap doesn't move freely.

[rlux4]

Have you downloaded any of the FI diagnostic manuals yet?
I mainly rely on these three to understand and troubleshoot the system:
http://www.artigue.com/?attachment_id=5
http://www.angelfire.com/wa2/fits/index.html#ljetguide
http://www.wcmotors.com/personal/Fiat%2 ... agnostics/
Mark's right, it's common for people to start replacing parts before they've done any diagnostics to find out where the problem really is.
The literature I've recommended will show how to test a sensor. A way to "lie" to your ECU is to unplug the connector on the temp sensor in the coolant "T", and plug in a 300 ohm resistor. This will signal the ECU that the coolant is at operating temp and the engine should run smoothly unless there's a different problem than either the connection, wiring or sensor itself.
Ron

[ExpertTees]

No I have not, Thank you for that. But I also figured if I kept replacing these random parts---pretty soon I will have me a brand new Fiat.

[rlux4]

You're fight there. And as they say "It vouldn't hoit".
Ron