starting problem

Hi i wonder if anybody may have had a similar problem i seam to be having with my 1993 3.9 efi Auto Range Rover, When i go to start her i have to keep the starter turning for at least ten to 15 seconds and it doesn't always work but when its tarts it runs like a dream, then it switches over to gas automatically and it will run faultlessly, but then if i stop and turn off the engine it might or might not start straight away even when it has been standing for for a couple of minuets or over night, i have taken the relays out and tried new ones but to no avail, can anybody shed any light on my problem please

What checks have you done?

I have checked all the relays on the fuel supply side, i am getting a spark as well, i have just ordered a new coil and see if that helps, and have tried to check all electrical connections but its still the same

plug condition ?

I changed the plugs as well, but the old ones were a light grey and the tips were cream like in colour, i know of a place that i can bits for my RR and was going to get an ECU and an air flow meter and anything else i can think of and swap things and just see if i can find it that way maybe

Don't swap too much over at once as then ye might not know exactly what the problem was. Have you checked rotor arm condition and movement? Also might be the ignition amp on the side of the dizzy. Notorious for failing due to its position as the heat eventually gets to it.

If it is a single point system and it runs well on LPG, I would be looking at MAF issues as a Single Point LPG doesn't use MAF data for fueling whereas the petrol system does....

Also check for splits in the intake ducting upstream of the MAF too....