hello!,

my car have the same problem, when try to start, the engine start and stop (cut off?!).

I check all fuses and relays, unmount relays for pump and injection, and put it unmounts to see if it works ok, and the relays are good and works OK!.

I check the fuel input, and fuel arrives ok to the inject rail.

I change the RPM/PMS Sensor, change sparks, check spark wires, and all its OK!.

I try to test the electical signal to the injectors, and arrives 11.4 volts when put contact, and when try to start the car, arrives only 8,9 volts to all injectors (I check all signals individually and arrives all 8,9v).

Fuel pumps its working ok, sparks ok, and fire its ok, relays and fuses ok... I try to insert manually fuel from air input to engine, and the car starts!!!!.

Can be all my injectors? into inject ramp (fuel comes to injectors) there is fuel, and I unmount any injector and fuel goes out.

I don't know whats happens!, my car is stupid!!!

If I insert manually fuel into air input, and the engine starts ok and don't stop (unless I stop insert manually fuel...), the problem is fuel do not enter into engine, but... if injector rail is filled of fuel, and injectors have electrical signal, I supousse the fuel must be enter into engine, but not enter.. I unmount injectors and mount it exit of engine, try to start the car and no fuel exit from injectors...

Can be injectors the cause of fuel don't enter into engine? can be the all injectors bad? how I can probe if the injectors are OK?

Thanks everybody!

I'm getting the same problem but with my Punto 60S mk1 (1998).

The car died on me mid-drive as if it had stalled and wouldn't re-start the AA guy said there was fuel pressure to the injector and all electrics working, spark plug, crank, etc after the injector but injector wasn't injecting fuel for some reason.
So I got another fuel injector from breaker yard but still no joy (the chances of two injector being faulty??) called AA guy out again and he says the same the fuel injector isn't working but they're nearly £90 (vat inc) brand new and 12 week lead time and I'm not sure if he's quoted me the right part and it's £90 wasted if this is the case.
So called a local mobile mechanic who sprayed some solvent based cleaner into carb and it started but dies after solvent was burn't and he can't pinpoint it either.
So I had two guys out from the AA both say fuel injector and one mobile motor mechanic who is also baffled.

I'm desperate has anyone ever heard of this before or can tell me what part number the fuel injector is so I can get a new one. Everything I've tried through google/ask jeeves just gets me tons of adverts wanting my e-mail address to spam me to death or adverts to buy cars.

HELP
Kind Regards,
Tired.

have a look at the top left hand of the fuel injection unit as you look under the bonnet,theres a plug bolted to the unit by allen keys.get a electrical tester light from the battery and run a live and earth test on the four connecting wires if the live signal lights up week run a straight live for now from battery,also locate the earth and run a good earth.this worked on mine yesterday after all the diagnostics had had a go.good luck.

it's all very well testing for open circuit voltage but all you will get is the potential voltage reading not the power under load this is were the humble test light comes in use it on the live feed to the injectors and then test the voltage I'm not sure what it should be on a multi point injection car is yours a punto 75 by any chance

petty sure it should be 12v or slightly less as you have said 11.5
anything below 9 is too low

spi punto's only require 5 volts to the injector

When you say injector signel is 9v, I assume that the common supply is 13v and signal from ecu is 9v. You can manually switch on any injector fully by earthing the signal from ecu, then injector should open , This will not harm the ecu because the ecu does not source the supply, it only dumps it. If the common supply to injectors is indeed 9v then fuse relays etc are suspect.
If injectors work then the pulse to them is suspect, check that MAP is not giving out of range reading, should be close to zero with no vacuum. If map is ok, then looks like ecu.