FORD FIESTA 2011 1.4L (SIGMA) CRANK NO START, HELP.

=12pxGood day to you all

=12pxI have a Ford Fiesta 1.4l (FXJA) that cranks but does not start. It came from another shop with bent valves and bent conrod. Valves and conrod was replaced and engine reassemblied and timed with proper tools and checked. Compression is good on all cylinders, spark is strong and consistent. The fuel pump was changed by the other shop (looks like a Pieburg). Sounds like it wants to fire up but never does...

=12pxI pulled a code reader and it gave  P0302 - cylinder no.2 misfire


=12pxNow, having checked everything to the best of my ability, I then came to check the injectors... they were spraying in a funny way. The spray pattern was appearing as V-shaped jet streams and not misty puffs. Also, while cranking the engine, the injectors spray and appear to stop spraying only to resume rather weakly thereafter. I wonder if it is a Ford engine management strategy to prevent flooding as the rpm would not have risen above an acceptable threshold value signalling to the ECU that the engine had started.

=12pxOn one instance it did start for a second after spraying starting fluid (without removibg the injectors) but never fired up thereafter.

=12pxSo I decided to remove the injector rail and a friend cranked the engine while I sprayed some starting fluid inside the injector ports and the thing started... This leads me to believe that this is where my problems lie: fuel delivery. Or, I could have a bad MAP, shorted sensor or a bad PCM.

I read codes with a cheap one and got:

P0302- cylinder 2 misfire detected

I will someone with a more advanced reader to read other codes if they are present and will post within a day. Just to add, the MAP connector was oily.

=12pxThanks in advanded timing
=12pxSizwe

your on the right track of the fuel , maybe they replaced the pump and not complete module w/regulator. check with pressure gauge . check wiring to pump , also i think it has a shut off swtich by glove box, i've heard of bad alt causing no start .

The pump was replaced as a complete module with regulator. I will check alternator and shut off switch. By the way, where is it located in this car?

Thanks
Sizwe

I think you will need to get your hands on a better diagnostic computer. I would suggest Forscan. It will cost you a $65 adapter but the program itself is only $12.

I will use the services of one guy who uses Topdon (not high-end, but hey).

Say, and suggestions as to where should I buy it?

You know what? I will look for shorted sensors, as I have not looked at 5v refs and ground intergrity etc. I have sourced secondhand OEM injectors from a vehicle that has overheated.

Man, how I wish I had a scope now, to eliminate a dropping crank signal and the like.

Sorry for the delay, I was occupied by another vehicle.

Thanks in advance.

Hi

Sorry for disappearing, work and life got the better of me... I now have time to focus on this car once again.

I was raising money for a really cheap oscilloscope for me to see the cam and crank sensor signals... and I found what you see on the picture ( imgur.com/4pVmQ0C ). This is my first oscilloscope gents, please forgive me if it is not clear and professional enough... I just wanted to see the waveform as quickly as possible.

First of all, I measured any voltage coming from the Blue/White terminal and the Violet terminal and I got 1.4~1.6V. I then measured the crank sensor voltage and got 2.5 volts if my memory serves me well. I do not know if these cars use bias voltages or not. Could I get confirmation on that?

Also, the cam sensor waveform was a sine wave and I did confirm that it was clean and consistent when cranking.

My main concern though is that I had to scale down to a 50mV/div setting in order for me to see the output waveform. What is even more worrying is the fact that the max voltage is 160mV, way lower than the +/-500mV signal required for the ECM to "see" the signal. I backprobed across both terminals and got the same signal and I backprobed across each wire at a time and I got the same result, no improvement on sensor signal strenght.

I poured a bit of fuel into the intake manifold and cranked it. It popped as if the timing (ignition or valve) was off. If you crank it without pouring gas, it sounds like it wants to start for a second and after a few cranking revolutions, you realise that it was not going to fire up. If my suspicion that the crank sensor is toast are true, then the it would meant that the cam sensor was throwing the spark or injector spraying timing off, thus causing the no start.

With the crank sensor (both sensors are inductive permanent magnet sensors), I easily saw the waveforms in a 5V/div setting and a max output of more than 12 volts.

I believe we are close to solving this problem here.

Thanks in advanve
Sizwe, from South Africa

Anyone?