Discovery 4 SDV6 hard starting

[transtar]

Engine turns over ok but does not fire. After waiting some 2-3 mins with ignition on starts ok. Is this sign of fuel tank pump on way out?

[Graeme]

Have the crankshaft position sensor checked by graphing the RPM using a diagnostic tool during start-up.

[DiscoJeffster]

Having had this exact issue, I concur with Graeme. A new Crankshaft Position Sensor sorted it. It’ll do this weird no start for some time and then it’ll fail on you whilst driving. It’s about then you’ll finally get a code that says what it is. As Graeme said, get a code reading tool capable of showing RPM and watch to see if the RPM signal stays solid. RPM comes from the CPS.

[transtar]

Thanks Graeme and Disco Jeffster

[350RRC]

Having had this exact issue, I concur with Graeme. A new Crankshaft Position Sensor sorted it. It’ll do this weird no start for some time and then it’ll fail on you whilst driving. It’s about then you’ll finally get a code that says what it is. As Graeme said, get a code reading tool capable of showing RPM and watch to see if the RPM signal stays solid. RPM comes from the CPS.

If they had a CPS at each end of the crank they could throw a specific fault code for 'that' really serious issue. [biggrin]

DL