fiat tipo sx ie

My tipo has had a worsening problem since i acquired it off an old man who gave it a sadly low mileage.....it drives like a bucking bronco,surging and
'pulling back' as you go on and off........it sometimes stalls when slowing approaching ,say, a roundabout......on a long run at speed it is usually good, with only occasional 'jerking'......it makes me look like a learner driver.... who cant control the clutch! Help!Ps, I need to pass on any ideas to a mechanically minded man,as he just says, huh, tipos are always bad for electrical problems.....
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Your car uses SPI - single point injection.
The unit is in very repsect like a traditional carb body, except that the normal jets are replaced by a single pulsed jet in the middle of the body.
Your mechanic needs to:
With engine OFF 1) remove the top of the air filter cover allowing him to see down inside the injection throttle body. 2) manually operate the throttle plate checking for smooth free rotation. (disconnect the throttle cable first) 3) check for smooth throttle cable travel and return (don't reconnect yet)
With engine running
1a) operate manually the throttle plate whilst looking inside the throttle body. The fuel injection/mist is readily visible and should respond to the manipulation. 2a) visibly check the idle control solenoid (acts on throttle plate shaft linkage). Should retract when the revs are manually lifted. Should extend if the car revs are slowed by a) dragging the clutch in gear b) restricting the air intake.
Stop Engine
1) reconnect throttle cable
Start Engine
1) Repeat 2a) above.
If all looks OK and problem still persits then the ECU possibly needs resetting/conditioning.
The ECU is adaptive and can memorise events/conditions/driving styles.
I believe, if I remember correctly the following procedure will retrain the ECU (suggest you try your own internet searches to confirm).
a) disconnect battery for 15 mins b) start engine and allow to warm up at idle till fan cuts in (about 15 mins) c) rev ingine to 3000rpm and hold for 3 to 5 minutes d) allow engine to idlel for 5 mintutes e) take car for a 'normal drive'
If in b) c) or d) the car performs irratically then there is another problem lurking.
Additional info I have from my files is:
Fuel Injection System --------------------- Bosch Mono-Jetronic (SPI) Single Point Injection System - A2.2 (data provided by Bosch UK) Air Temperature Sensor: 2.23K ohms at 25 deg.C. (approx. measured) 1.91K ohms at 31 deg.C. (approx. measured)(finger temp) (two outside connector pins) Water Temp. Sensor: 2.43K ohms at 24 deg.C. (approx. measured) 329 ohms at 75/80 deg.C. (approx. measured)
Digiplex 2 Pinout -----------------
1 - ground to retard ignition by 3 degrees 2 - ground to retard ignition by 6 degrees 3 - starter motor solenoid +ve 4 - throttle valve sensor 5 - ignition coil +ve (supply) 6 - idle cutout 7 - TDC sensor 8 - TDC sensor 9 - diagnostic 10 - ground 11 - ignition coil -ve
Pin 1 is the first pin from left hand side when looking at the pins on the digiplext unit. Pins 1 and 2 normally have no connection to them!
--------------------- Digiplex Unit ------------------------- o o o o o o o o o o o ------------------------- 0 0 0 0 0 0 0 0 0 1 1 1 2 3 4 5 6 7 8 9 0 1

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thanks...I'll try that on wednesday .....you sound like you know what youre on about!!!!!!!
Nick ///// wrote:

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I'm working from memory.
Had a Tipo SX myself and it was a great and very reliable car.
With 'modern' cars (modern = fuel injection + who knows what) one has to think back to basic engine operation and work forwards from there. At the end of the day the objectives are the same. Squirt/drag some fuel and ignite it. The only complicating factors are how much fuel and when to ignite it :-)
Let us know how you get on. My ideas may be well off target but once elimiated narrows the options down for others to have their say.
Either way I win ..... only joking :-)
Nick /////

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