PeteMck

OK. So now got it running again. Pressure increases when I squeeze return line but still seems to be only around the 27 / 28 psi mark. So think I might have to change the regulator on the back of the fuel line. Although the fuel table is starting to look more "normal". Anyway now got a new problem. just had it idling and run it up to temp and the exhaust is glowing at the back of the cat. Did have to twist it through 90 degrees to get it to fit against the chassis but it shouldn't have caused any restrictions. Currently using disco 4.0l manifolds and disco 4.0l exhaust Y piece and then 3" home made after that.

Ah right. I'll have a play with that then

Merry Christmas all. Right so I've changed the fuel pump and filter and have 2.5bar pressure now. So tried to start and no joy, wet plugs. So figured it was now over fueling. So I changed the fuel map back down to more sensible numbers and still no joy. Getting spark and fuel but wont fire. Just getting the odd cough and splutter. rpm now only reading around 150 when cranking but sounds quicker so could that be causing an issue? Any other suggestions? Tia

Well I've changed the fuel pump and now getting around 35psi pressure. with the current fuel map it won't start it just floods the engine so definitely getting more fuel. Forgot the laptop so can't change the map 🙄 but hopefully that will cure the problem.

Yer it's an efi filter. And yes it's a regulator on the end of the fuel rail. Havnt tried clamping the return. Will give that a go when I get the chance.

Filter is new but it's an inline filter rather than the standard one so could be restricting it I guess. Will have to find the specs for it again and make sure it can handle the flow rate. The joys of nothing being standard 😂

Right. Well that's going to be next on my list of things to check then. I'm guessing it could pump regulator or filter. Easy way of ruling any out? Slowly getting there.

One other thing about the spark timing. To get 10 degrees advance using a timing light, I had to set it to 16 degrees. Now that I'm back on the map is that how that should look?

Right. Well I've got just over 1 bar of fuel pressure / 18psi. Standard 4.6 gems. Anyone know what the pressure should be?? I get what your saying re each map / engine being different but surely if I end up with req fuel 70 or something stupid something somewhere is wrong?

Hmm so then if I need 60 in my ve table to get a half decent idle with req fuel at 20 does this suggest fuel issue?

That the current spark map I'm using. Think it's pretty sane 🤪

Don't no has can't see the rail (where I have the gauge) and rev it. Will try and find out. Injectors are standard gems. Oh right Yer well I found a spark map that looked like it made sense so used that as a starting point. Same for ve table.

yer i checked tdc. fuel pump is straight out of a p38, took it out the tank and checked to make sure it wasnt blocked or anything, plastic tank so no rust issues. did wonder about the regulator on the end of the rail. is there any way of checking them? now that ive managed to get a more stable idle and stopped the wild hunting the fuel pressure has remained more constant. the engine will rev though, so surely its getting enough fuel to hold a steady idle? when you say fixed the spark table...?

20 bit more reading later and starting to wonder if ive got my spark settings right. does that look right?

Yer I was reading something about that earlier. What I'm concerned / confused about is why my ve table values seem so high? Anything bellow 57 and it starts hunting like crazy. Could this be due to a poor spark map? Did get a timing light on it and it seems pretty close. Maybe only 1 or 2 degrees off where it's set. Was around 8 degrees advance instead of 10. Assuming this means I need a trim value of 2.

Right, bit of an update. Resealed plenum, etc, only one I haven't done is valley gasket. Can get MAP down to around 43-46kpa rpm float from 790-860. Ive got fuel map around 58-60 and it sits there and hunts a tad, hence the rpm all over the place. Then if I stick the fuel values up to 65-67 the rpm will change between 960 and 990 and the map stays at 39 kpa. If I drop my fuel values bellow 56 then it stalls. To put fuel values into perspective required fuel set to 20. Any suggestions? Could it still be a vacuum leak?

OK. So I've rechecked the plug leads and they are correct and the edis ABCD wires are all round the right way. I did have the bypass screw wound out 5 1/2 turns. No idea if that's a lot or not...

As long as I can find a gauge that will fit in the defender dash that works with the rr sensor I'm happy.

Originally a 1989. But now being hacked up and traybacked so the tank sits in the middle of the tray at the back. Will probably lose the original rangie tank as don't like the way it fits but will keep the pump unit.

Cheers

OK. So I have no manuals. Where can I find them? I initially thought plug leads so have triple checked those. After hours of googling I am starting to wonder if my edis ABCD wires are round the right way so need to check them. Will post a load of pictures when I next get over to the vehicle which should be Wednesday. I know there is no easy shortcut, I just don't want to spend hours and hours tinkering with a map to find its a mechanical issue and visa versa. I really appreciate all your help as I'd be screwed without it 😁

Yer that's the screw I've been playing with. Presumably opening up that too much would have the same effect tho? OK so the hunt for a vacuum leak begins. What kind of pressure should I be expecting?

If my idle pressure is at 52/53kpa is it possible to tell if it's got a vacuum leak or not? Or do they vary to much?

Reconditioned engine gone into it so hopefully should be in reasonable health. Will double check all the pipework again. Have next to no experience with v8s which makes life harder. Should have stuck to diesel. Lol have been fiddling with the butterfly valve to try and get a stable idle so may have opened that up to much.

😣 any suggestions on what mechanical issues could be causing it? This is starting to hurt my head 😂