rough running

[72fiat850]

I have a 1981 2000. Most of the time runs great, smooth. But twice recently I had to go rescue my 17 yr old son. He took it to school, no problems, but coming home started to run really rough, no power. He was able to pull into a side street and call me. I could get it to start, but the whole car was shaking, a lot of smoke from exhaust and no power. After about 1 minute of coaxing it started to run smooth again. We've had it a year, and cleaned gas tank out with new filter was on of the first jobs. Just debris in line or FI or something else? I'm afraid to let him drive it, which is killing him. Any help would be appreciated.

[TX82FIAT]

check fuel filter for any particulate from the old lines that may have come loose with use. what color was the smoke? If it was white smoke you may have a head gasket issue that is magnified when the car is driven hard. older cold twin cam driven hard right after start up is not a good thing.

You are going to have to do some deductive reasoning with troubleshooting guide to isolate the possabilities.

[majicwrench]

What color smoke is, like said above, a key point.
Keith

[72fiat850]

It was black, black smoke, I had a head gasket go years ago in my 850. It was nothing like that. I had a bellow of white smoke in front of my old dorm. We'll run the fuel lines this weekend to make sure everything is clear and clean. Thanks for the quick response.

[TX82FIAT]

Black smoke is most likely a fuel issue. May even be a leaking injector, restricted line/filter. The car could be running lean.

[redcars]

Sounds like your temp sensor for the ECU. It is on the coolant outlet T on the bottom. Look at your connector and see if it is in good shape. It could be just a bad connection. If it does not receive this signal it sees the engine as cold and give it more fuel, which makes black smoke.

[So Cal Mark]

I'd bet the afm flap is stuck when you experience your issues

[72fiat850]

Thanks for the input, looks like we will have a busy weekend I'll let you know what we find

[72fiat850]

Opened up cover on AMF-- you were right, it was stuck. Touched it and it sprang back into position, cleaned the area with some contact cleaner running much better. Looking over some previous posts it was suggested that a screw was loosened and the arm should be moved a bit to contact a better area. is it the screw in to middle of the black plastic? just want to make sure before I change anything thanks

[narfire]

You'll see a nut on the shaft. Back that off and slide the arm up or down just a tad so the pins contact a clean section of track. Might have to take the assembly off the shaft and some will give the arm a very slight bend to get it on a clean section.
Good luck
Chris

[72fiat850]

Thanks, was just back looking at previous posts and realized what I needed to do. my son drove it last night. Had to go rescue him. I was able to limp to a friends house. Left it in front, what a surprise for him the mourning. I was able to get it to my office at lunch, rough the whole way. It's running well enough now to wait to play anymore until I get home. Afraid to tamper anymore until it's in the garage