Technical 1.1 mpi no start/tickover without "help"

[digidash]

got an 1100 mpi in that will not start without petrol down intake. once given petrol will run as long as revs held on. release revs...cuts out then will no start unless given more petrol. faults come up for phonic wheel and iac. cannot do phonic relearn as wont tick over. has had a new cam sensor and timing checked spot on. if disconnect crank sensor wont start at all. if disconnect cam sensor it makes no difference...ie starts with petrol. ecu pins are in good clean condition and all earths have been cleaned. any ideas appreciated (i have fiat ecu scan soft and that also doesnt do phonic relearn. thanks steve

 

[randomizered]

I'd suggest faulty iac then. not enough air at idle to maintain combustion and the engine dies.

 

[dronenrs]

:yeahthat: thats your first port of call

 

[digidash]

forgot to say injectors not sqirting with inlet manifold off and not pulsing with noid lights on crank, thanks steve

 

[dronenrs]

sounds like a fault in the injector circuit then. so check the earth and trace the wires and check for voltage anywhere you can. on the live.

 

[digidash]

does anyone have a wiring diagram for this engine, with ecu pinouts would be a great hepl if poss. are injectors 12v or 5v? are they pulsed earth or pulsed feed? any ideas why they don't operate on crank but obviously work on high revs? thanks for help, steve

 

[dronenrs]

if it stays working at high revs then i would actually consider a sensor .. could be a dodgy crank sensor thats not picking up a good enough signal at low revs does it bump start if your moving quite fast ??

 

[digidash]

haven't tried bump start but engine "flies" over on starter, might try a crank sensor anyway, thanks steve

 

[digidash]

forgot to say car is 2002 and when cranking eml flickers, i reckon this is down to phonic relearn that i cant do and would not stop car starting...please correct me if im wrong, thanks steve

 

[digidash]

just to bump....crank sensor on order. also i still need wiring diagram if anyone can help. (this is mpi not spi) thanks steve

 

[rallycinq]

Downloads have the diagrams.

The ECU switches the earth.

Cheers

D