I have a problem with my Fiat Bravo ’08, 1.4 turbo T-jet 120hp( similar engine as in the Chevrolet Cruze, Dodge Dart, and Fiat 500).
Every time i do a cold start ( the car has been sitting for more that 3-5 hours) the car starts up just fine, idles for 3-5 seconds and then it sputters and dies. It does this 2 or 3 times and then it won’t die anymore, but for the first 1-2 minutes the car is very jerky/ lacks power.
After it’s warmed up there’s no sign of any problems: idles ok, runs ok. The problem started about 1 year ago and it got increasingly worse, at the beginning it would just sputter for a bit and then it was fine.
I had a scanner on it:
-it has no stored codes.
-coolant and air intake temperature sensors report ok.
-did not find a vacuum leak (tested as Eric has shown)
-the MAP sensor reports reasonably close to the ECU expected amounts.(and since it’s a MAP i would not expect a vacuum leak to cause problems)
-tested the fuel pressure in the rail at cold start: 3.5 bar with engine off or without the vacuum hose connected, pretty stable, it drops to 2.5-2.8 at idle .. so that seems to be ok.
-fuel pressure bleed off seems a bit more than expected.. drops to around 2 bar in 10 minutes.. but it goes right back to 3.5 in 1-2 seconds with the ignition on… so not that bad.
-no blockages in the intake system.
-replaced the spark plugs.
-replaced the fuel filter.
-checked the EVAP solenoid- works fine.
-had the injectors out, tested the with an ohmmeter and they are all really close in readings( don’t remember the exact figures. but i remember looking up the official figures and they were close)
-tested the injectors (using the two-way obd2+laptop combo I’m using) spray pattern looked fine and uniform across all four.
-cleaned the throttle body that is ok.
-It has a coil on plug system. don’t know how i could test them.
-With starting fluid added to the intake it no longer sputters.
-LTFT was only about -7% at one time, i then reset the ECU and the LTFT to ZERO to see if that would make any difference- it did not.
– What makes a difference is the level of fuel in the tank, when full it only sputters; as it drops it sputters and dies, even tho the pump is still completely submerged in fuel( and altho fue pressure is still ok)
Any suggestions are welcomed!
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