Vr6 starting puzzle

[captainredeye 0]

The vr has suddenly stopped starting picked it up from a wheel alignment drove it to work left it for 30 minutes then just wouldn't start, I have fuel and a spark but the engine won't burst into life.

Every now and again I get a short pop from the exhaust also to not the Rev counter doesn't move when trying to start apart from the odd occasion where you get a quick blip, any ideas?

Have also just replaced the crank sensor.

[fendervg 32]

Is it cranking? It might be an earth or wire to the starter has been disturbed during the work.

[captainredeye 0]

It definitely turns the engine just no combustion

[fendervg 32]

Did it start ok after you replaced the crank position sensor?

[captainredeye 0]

Replaced the crank sensor and still no joy, the Rev counter occasionally moves a little when cranking, I have checked the spark again and the Sparks don't seem to follow a regular pattern as you would expect from the fireing order.

[fendervg 32]

I meant to say is the crank sensor you replaced a known good one? Did you test it before fitting and was it new or second hand?

[captainredeye 0]

ah i see no i didn't test it but yes its new, that will be first thing to check

[fendervg 32]

Yep, a faulty CPS will mean the engine won't start at all - that might not be it but it's the first thing worth checking.

[captainredeye 0]

Been a while, i have just replaced the fuel pressure regulator on the end of the fuel bar and hey presto after a couple of cranks the relay clicked and we have life. now for the next gremlins that show themselves.