1981 FI Bucking Bronco

[emosfiat]

Hey guys. My 1981 FI has started to give me a new sensation, bucking bronco. Starts fine, idles good at 1000 RPM and warms up good. After a while I feel some hesitation when idling. When I try to rev up or drive then it feels like I run out of fuel. Bucks and jolts. Let off the gas and it stops bucking. I am asking for info before I take it to a shop. At this point not much has had to be done to the fuel system to get to run. Any help will be greatly appreciated. Thanks, Emo.

[So Cal Mark]

check the air intake hose for cracks

[emosfiat]

Mark, I checked and replaced vacuume hoses and aux air hoses just in case. I checked the air intake hose. Ther were no breaks or cracks. all clamps are good and tight. Still have the same problem only worse. Now it will not stay running under load.. Will restart and idle good but as soon as you step on the gas it starts to bucks and dies. I discovered that my air flow sensor flap was dragging (rubbing) inside the chamber. Not sure what caused this. I cleaned the chamber and it is smoother but it still rubs in places. Fuel pump is making more noise now, so I will replace it. It still feels like it is starving for fuel.

[So Cal Mark]

the afm flap has to move freely, if it's dragging you'll have to repair or replace it

[emosfiat]

Is there a trick in repairing the air flow sensor? I have tried emry cloth on the surface of the chamber, prying the flap down and just plain cleaning with carb cleaner. Does the flap come out of the chamber? I did not see how it is assembled. These may be stupid questions but I am a little frustrated at this point. I know, welcome to Fiat reality.

[So Cal Mark]

the flap can warp, usually from a backfire. To disassemble it you will have to drill out the rivets holding it together

[radiopilot]

Emo

I had the same problem with my 1982 FI, tried everything like Mark indicates, but the problem turned out to be electrical, I replaced the battery and the cable to the alternator, sure enough car runs perfectly, not saying this is the problem you have but the car did exactly as you describe... simple fix and I know you probably need a new battery right?

Nick

[So Cal Mark]

all of this advice is predicated on the basics being right; fully charged battery with tight connections, good clean grounds, fuel in the tank, etc

[emosfiat]

Thanks guys. I am going to work on it this weekend starting with bat terminals. I have a new battery. Next I have a real noisy fuel pump so I am going to change it out. I will look at the air flow sensor to see if I want to attempt to take it apart to free up the flap. Got to look at this close. Don't want to screw it up. Mark, I have not looked at the ignition yet. I replaced the mag pick up coil but could the vacuume advance cause the pick up wire to have a problem and cause the engine to loose spark under accelration? I will look at this also. Emo.