common issues with fuel injection?

[carlospena96]

Well, I have a 1981 fiat spider fuel injected, and it is a headache, my car was good, but then back to home my car start having aceleration problems, when the car is in idle all good, but when the car start moving, it jumps and its imposible to drive , when i check the spark plugs, the four are all black , I check everything, check distributor, new coil, injectors all good, new spark plugs, new lambda sensor (oxygen sensor), check all the sensors with ohmnimeter with help of the maintenance manual and all was good, I don't know if the ecu is damaged, I need help!

[76was124]

Did you check that the flap on the Air Flow Monitor (AFM) is not sticking?

[carlospena96]

Did you check that the flap on the Air Flow Monitor (AFM) is not sticking?

Yes, I check it and check the ohmns

[wizard124]

Pull the connector at the AFM, look carefully at the individual contacts. Ensure there isn't a contact that is deeper in the connector, creating a poor or intermittent connection.

[narfire]

OK several things.....
Under the dist cap the two wires are thin and get brittle with time, they can cause grief.

Non metered air getting in from a leak in the main plastic intake, brake booster diaphragm (brakes are usually an issue as well with this), aux air valve acting up.
Check the two injector grounds that are attached to a couple of bolts holding the intake plenum down.
Another is the strip inside the AFM box can get warn and can cause grief. One has to pop the black plastic top off and adjust the pins perhaps 1/2 mm so the pins run on a "clean" part of the strip.
Just for something to do, turn the engine so all the timing marks are lined up....perhaps the belt jumped a tooth or two?
Injectors themselves are sticking.....remove and take them to a place that will flow test. I had a bum injector once found after testing. Notable performance increase after replacing with a know good injector.
Chris