Everytime I go to start my V8 I have an excessively long crank time. Once it’s running it’s sweet but when it’s sat any longer than 5-10 minutes it will just crank for a good 5-6 seconds before firing up.
So far I’ve replaced the coil pack, o2 sensors, ignition leads, spark plugs, MAF sensor, intake manifold gasket and I’ve had the injectors resealed. Wondering if anyone can point me in the next direction?

 

First thing that comes to mind for me is fuel pressure....been a lot of those threads here lately. You're probably throwing a long/extended start time soft code.

Do you hear the fuel pump prime when the key is cut on?

On our 99 it would give random long starts. Ended up being the fuel pump relay was acting up. This is easy to rule out. Open the hood. Open the fuse box cover. There is a line of yellow relays. The one closest to the radiator is the fuel pump relay. Remove it and swap it with a another.

If problem goes away buy a new one plus a spare

If it doesn't goes away it's time to check fuel pressure.

Any time I've disconnected the fuel rail on the disco it results in long start times. I suspect the disco 2 is like most other modern fuel pump bucket assemblies and has a check valve. If this valve is bad she'll allow fuel to drain back into the fuel tank when you cut if off.

A fuel pressure gauge will help determine this but you'd also like to rule out an injector or injectors possibly leaking down when she's turned off.

 

I agree with fuel pressure. I suspect it’s bleeding off as the car sits. The most likely cause would be a check valve in the fuel pump, second would be an injector. But I would suggest some troubleshooting shooting before throwing more parts at it.

 

put a Fuel pressure gauge on the fuel rail (sucky part is getting to that dang fitting). when you turn the key on it should prime up the pressure and the pressure should NOT bleed off for quite a while if at all...if it bleeds right off...most likely it's the regulator which is part of the pump.

 

I never hear the fuel pump prime when I turn the key but it always starts so surely that must mean the relay is working otherwise it just wouldn’t start.

The pressure drains off very quickly after the engine is cut and I’ve suspected a dead one way valve for quite some time however it’s irritating that I have to replace whole pump assembly to rectify that when the pump itself still works.

 

yeah I definitely think it’s the check valve, I had the injectors rebuilt not that long ago. Do you know if it’s possible to replace just the check valve or is it a full pump assembly replacement?

 

There's a cheap one on parts geek for about 80 bucks. I've not torn one down to look for the return valve, not sure LR sold anything other than an entire assembly for these gasser models.

Also worth noting the 80 dollar one was 99-02. Not positive if the 03-04 interchange. I have an 03 fuel tank in our 99 but cannot remember if I used the 99 or 03 fuel pump assembly at this point. The leaky fuel tank was the first issue we repaired on the disco... which led to the purchase of an entire non runner disco as it was about as cheap as what people wanted for the fuel tank.

 

Always nice to have backups. I did the same recently, asked my local rover junkyard guy how much it would be if I went and pulled an engine, and he said $500. I picked up a parts truck with a good block and no title for $350 last weekend lol. And now I have a whole vehicle to rob parts off of.

 

If you have the space, a parts vehicle is worth a lot.