Bucking bronco

[smokey14]

Hi I've got a problem maybe you all can help me with. I've got a 1983 Pinin 2000 fuel injected that when I start cold I can shift up through the gears with little or no problem but when the engine heats up and I've been running for a while in 4Th or Fifth gear and I slow down, when I start up from a stop I can't get through the lower gears without a lot of bucking and if I take it out of gear and rev it up it seems to want to choke itself out. Thanks for any help !

[So Cal Mark]

check the flap in the AFM, make sure it's not sticking at some point in its' travel. Also check the temp sensor resistance when hot.

[smokey14]

Mark I checked the air flow flap and it moves through it's full range without any problems. I am not a mechanic so I hope you bear with me, Are you talking about the lambda sensor and if so how do I check it's resistance. I should also tell you that shortly after I got the car it ran fine about 150 miles, it stalled out and would not start , I had the fuel tank cleaned there was about a half inch of rust in it and I replaced the fuel filter and it started up and seemed to run well until I went for a longer drive. Thanks Rick

[So Cal Mark]

not the lamda, but the temp sensor in the water outlet. That's the most critical sensor in your FI system. If you had that much rust in the tank, I hoped you replaced the fuel filter, and there's a good chance you'll have to clean the injectors as well

[rlux4]

Rick, if you don't have it already, print out brad Artigue's manual: http://www.artigue.com/fiat/Pubs/Artigu ... 124_MM.pdf.
It has a good FI section that will help you identify the location and purpose of the sensors on your car.
Ron

[smokey14]

Ron, I copied the manual you told me about and am going to use it. The temp sensing unit is the one mounted in the heater hose union in the front of the engine so I disconected the plug and cleaned the contacts also the wiring to the plug was resting against the union so I adjusted it away from the heat. I also put a bottle of fuel injector cleaner in the tank and checked for leaks in the air system. I ran it around the circle I live on, about a quarter mile, until the temp went to just over 190 and I only got a little stutter out of it, seems to be running better. I had filled the tank about 2 weeks ago and I'm thinking maybe some bad gas. Thanks! Rick

[rlux4]

That's good to hear Smokey, thanks for the update. Further down on Brad's page you'll find good wiring diagrams that can be printed out in large size, and if you ever need to run diagnostics on your FI control circuits (dual relay and ECU) you'll find a good set of pages here: http://www.wcmotors.com/personal/Fiat%2 ... agnostics/
Stay between the ditches,
Ron