Range Rover Classic 1994 3.9efi Hotwire ignition won't start

[GJA1983]

Hi guys sorry to have to do this but I am completely stuck with my V8 rangie, I bought it as a non runner and so far had no luck in getting it to start. Initial inspection confirmed a dud fuel pump which was replaced now the fuel system primes correctly and can be heard flowing in the fuel rail.
There is a spark and plugs look pretty new. I have checked the firing order which is correct but still it won't even try and start even with a squirt of dreaded easy start it won't even cough :-( if anyone has any experience with these cars some advice would be greatly appreciated. Thanks guys!

[andyb66]

How do you know that there is a spark? If you are putting the easy start into the air intake then it should still try and fire even if the injectors are not opening. Also if the fuel pump is working then it should run for about a second if the 'cold start' injector is working. That one is not triggered by the ignition pulse.

[GJA1983]

We have pulled various spark plugs out and earthed them to the chassis and cranked it over and it sparks but to me it seems irregular like big spark nothing nothing spark spark spark nothing spark etc the plugs are not old at all, I am wondering if it could be to do with the ignition amplifier is there a way of checking that? I have never owned or worked on a v8 rangie before so everything is new to me, sorry for my ignorence :-)

[GJA1983]

also the ht leads dissy and rotor arm all look pretty new also, i think the previous owner has been trying various things to make it run

[camel_landy]

GJA1983 said:

I am wondering if it could be to do with the ignition amplifier is there a way of checking that?

Avoid the temptation to jump straight into the complex stuff... A complete non-starter like this will probably down to something simple and quite fundamental.

Remember, you need 3x things for fire... Fuel, oxygen & ignition!

• Fuel - You say that you can hear the pump priming & fuel in the rails. Is fuel getting into the chamber? Crank the engine for a while... Can you smell fuel? If not, there's a problem... I doubt that all injectors would fail at once but instead whatever is controlling them.
• Oxygen - I doubt this would be an issue but just check that everything is clear... Even if there was a problem, you should at least get a splutter!!
• Ignition - You say that you are getting some sort of spark. This is a good sign. The Rover V8 is quite sensitive to the quality of HT leads, etc... But this would only make it run rough. Check the earth to the engine and maybe just supplement it with a jump lead from the battery to the block as a temporary measure.

That said, from your description so far, I'd be tempted to look in the area around the fuel injection and what is controlling it. I'd be looking at the 'trigger' from the engine (is there a sensor on the flywheel?) or if there is something like a common earth/fuse for the injectors. If you get a regular spark from the plugs and you can find out if it shares the same crank sensor, you can probably discount that one as the problem.

That's what I'd probably start with.

Good luck.

M

[andyb66]

camel_landy said:

* Fuel - You say that you can hear the pump priming & fuel in the rails. Is fuel getting into the chamber? Crank the engine for a while... Can you smell fuel?

Remove the fuel line from the fuel rail and stick it into an old milk bottle

camel_landy said:

I doubt that all injectors would fail at once but instead whatever is controlling them.

Controlled by ignition pulse as I mentioned

[GJA1983]

thank you for the replys guys spark is good but no smell of fuel or sign of it in the chambers plugs are dry...

[camel_landy]

andyb66 said:

camel_landy said:

* Fuel - You say that you can hear the pump priming & fuel in the rails. Is fuel getting into the chamber? Crank the engine for a while... Can you smell fuel?

Remove the fuel line from the fuel rail and stick it into an old milk bottle.

...still doesn't tell you if the injectors are squirting the fuel into the chamber.

andyb66 said:

camel_landy said:

I doubt that all injectors would fail at once but instead whatever is controlling them.

Controlled by ignition pulse as I mentioned

Exactly... But where is it & what creates it? Is it on the flywheel?

M

[camel_landy]

GJA1983 said:

thank you for the replys guys spark is good but no smell of fuel or sign of it in the chambers plugs are dry...

OK... So, it's sounding like you haven't got fuel getting into the system.

Time to start tracing back...

Do the 'milk bottle' trick mentioned previously, to make sure that you do indeed have fuel getting to the injectors. Once you have confirmed fuel is there, you need to start troubleshooting the injection system itself. For this, a wiring diagram and something showing the location of all the parts will be useful.

My money would probably be on the sensor that triggers the system. I'd guess that this triggered from somewhere on the crankshaft.

M

[camel_landy]

OK... A quick 'Google' threw up this:

http://www.4x4forum.co.za/forum/showthread.php?t=8...

About 3/4 of the way down, you'll find a couple of .PDF files, one of which is the Land Rover workshop troubleshooting guide.

However, reading through the thread reminded me of something which we have forgotten to check... The Immobiliser!

It could well be the immobiliser which is killing the system. Try the key fob to lock/unlock the car a few times. If that fails, try bypassing it. The best way of bypassing is to use a specially adapted plug but it can be re-wired. Another 'Google' should give you the details.

The immobiliser is tucked up behind the glove box.

HTH

M

[GJA1983]

OK thanks chaps, when i checked my new fuel pump i removed a fuel line at the left hand rear side plenum chamber when the engine cranks it does spew out fuel at an extremely fast rate... I tested power at the injectors and it did flash but i since found out its a negative switch. the black and white wire is connected to the neg side of the coil, i also read that the same signal tells the fuel pump to run when cranking/running and when I have finished cranking i hear the pump for a second then it stops, so does that mean its ok?

[andyb66]

camel_landy said:

I'd guess that this triggered from somewhere on the crankshaft.

Nope. Negative side of coil goes to pin 1 on ECU. The ECU turns on the fuel pump and puts 12v to the fuel relay. This put 12v on the injectors and the ECU switches them to earth to make them fire. It is the power to pin 1 that will basically make the injectors open. There is not crank sensor on the 14CUX system (which is what you have). Pretty much all I have to say by way of assistance is covered here http://www.g33.co.uk/fuel_injection.htm So sit back and read that. It will be something simple in the end, it is not a complex system. You just have to be methodical.

[camel_landy]

andyb66 said:

Nope. Negative side of coil goes to pin 1 on ECU.

OK... So it gets it point of reference from the Ign timing. So if it is sparking, the EFi ECU is getting a timing pulse.

I'll let the OP read through the troubleshooting stuff we've thrown at him.

M

[GJA1983]

Thanks guys, am reading all the info you sent me cheers

[GJA1983]

Ok checked the signal for the injectors and its fine, so now i am completely stuck, how can all 8 cylinders be dry if it has a signal and fuel? Should the fuel return on the regulator be open or closed? EG let fuel flow freely or should it be closed? Just wondering if there is no pressure in the fuel rail and just a free flow of petrol...

[camel_landy]

GJA1983 said:

Ok checked the signal for the injectors and its fine, so now i am completely stuck, how can all 8 cylinders be dry if it has a signal and fuel? Should the fuel return on the regulator be open or closed? EG let fuel flow freely or should it be closed? Just wondering if there is no pressure in the fuel rail and just a free flow of petrol...

Although there may be a signal, can it complete the circuit? i.e. could there be a faulty earth or something similar??

M

[GJA1983]

if i have a test lead on one connection then the other to the chassis it will show an on/off/on/off sequence when cranking but when both test leads are in the connector nothing? no change what so ever in the reading...

[GJA1983]

Scrap that last post there is a proper signal in the injector connectors on off on off, but after about 45 seconds of cranking it slows down to a slower pace.

[GJA1983]

Ok after much research and reading I am thinking the injectors are blocked because when I pulled the fuel pump the fuel was rusty orange inside the old pump, also it has a little bag filter and that was shocking can anyone recommend a good cleaning service by post?

[GJA1983]

UPDATE: After a diagnosis of no compression in cylinder no 7 it was clear a strip down rebuild was needed. I stripped it down, found the inlet pushrod for no 7 had bent and fell into the valley, luckily not damaging anything, whipped the head off and the valve had ceased. So then I stripped down both heads and replaced the valves, lapped etc. Rebuilt the engine and got it ready to start this morning and it coughs but wont start compression is about 100psi across all cylinders, obviously until it runs and the pistons rings seal properly it wont be accurate but at least its consistent.

I believe its a weak spark as when I take out a plug to test it sparks but the click sound isnt very loud and the actual spark isnt that big, in fact it sort of wanders around the electrode. Where do I start with a weak spark? I have connected a direct supply to the coil and it did help but still not fired. As a final note when it cranks the first few times are the most promising but after a couple of seconds it just doesn't even try. Thanks in advance guys.