Classic RR Classic 1989 (3.9L V8 Auto) - Cuts Out

Hi All,

I have a bit of an issue with my Range Rover Classic 1989 (3.9L V8 Auto) Vogue. In short the car starts first time, but if I have the bonnet down after about 5 mins the engine cuts out. After making tests I have discovered that the voltage to the ignition coil vanishes. I am wondering if something is overheating to make this happens but wondered if anyone had any tips?

Looking at the wiring diagram I guess its one of the following making the issue.

-
ECU connector (1) pin 39
Cable - white/black
Coil(16)
Cable - white/blue
Engine harness connection (41)
Cable - white/blue
Fuse C3 (42)
Cable - white
Ignition Switch (9)
+

Have a look at the crank position sensor they have a habit of going south when hot.

Doesn't have one or a camshaft position sensor.

Notable item affected by heat on the RRC is the ignition amplifier on those that have it mounted on the side of the dizzy. So much so that LR did a kit to remotely mount them on the inner wing STC1856.
I understand that it's vital to use the special grease if you leave it on the side of the dizzy.
Old but worth a read: https://www.landyzone.co.uk/land-rover/range-rover-classic-no-spark.34925/

Ok that counts out the CPS as there is not one, thought it had one as ecu was mentioned

JJHawk said:

Hi All,

I have a bit of an issue with my Range Rover Classic 1989 (3.9L V8 Auto) Vogue. In short the car starts first time, but if I have the bonnet down after about 5 mins the engine cuts out. After making tests I have discovered that the voltage to the ignition coil vanishes. I am wondering if something is overheating to make this happens but wondered if anyone had any tips?

Looking at the wiring diagram I guess its one of the following making the issue.

-

Click to expand...

The supply voltage to the coil is from the ignition switch to the plus coil top terminal, unless u have an immobiliser fitted interrupting it.

brianp38dse said:

Ok that counts out the CPS as there is not one, thought it had one as ecu was mentioned

Click to expand...

The Classics are - relatively - simple things electrically. Good job as my electrickerycomputery thing skills are very limited!

Hi All,

Thanks for you input so far.

I have rechecked the "Range_Rover_Manual_1992" and it states that the 1989 has a ECU so I am now a bit confused. I have also checked under the drivers seat, where the manual mentions the unit should be located, and it seems to be there. See attached.

I guess based on this the CPS could still be the issue as mentioned by brianp38dse? Any thoughts?



Reagrds
J.

I am out of depth now as i thought there was a sensor
Ratae is more switch on with classics have you done his checks.

brianp38dse said:

I am out of depth now as i thought there was a sensor
Ratae is more switch on with classics have you done his checks.

Click to expand...

No, But I am not working tomorrow so I can not wait to check!! Thank you both

It will have an ECU, as do all the Classics with fuel injection starting from the 4CU on the 3.5EFI introduced with the 1986MY.

Classic ECUs control the fuelling, not the spark unlike the P38 which controls both. (FWIW mine has LPG set up so when on LPG the injectors are turned off& doesn't even need the ECU to be in the car when on LPG, something that has proven handy on a couple of occasions when I've had an ECU go wrong, the 4CU on mine having a certain notoriety)

The 14CUX ECU detects engine speed from the coil & doesn't have a sensor on the engine.
There is a road speed sensor mounted on the chassis but this has nothing to do with the spark, only fuelling.

As your spark disappears as things warm up my suspicions fall on the ignition amplifier or the coil. You need to carry out the checks in the manual.

ETA. There is something rattling around at the back of my mind of a similar issue from a long time ago on another forum where everything tested fine, but it still turned out to be the ignition amplifier but I can't remember which forum it was.

You might also find this of interest but bear in mind it isn't specific RR: http://www.britishv8.org/Articles/Rover-14CUX-EFI.htm

Dunno if you sorted this yet but FWIW I would suspect ignition amplifier. If you swap the amplifier, it is possible with care to do it without pulling the distributor but to be honest it is just as easy to pop the dizzy out, but make sure you mark the position of the distributor before you pop it out and remember the rotor arm moves as the spiral gear engages/disengages and you also have to line up the dizzy to the oil pump drive. You will need to coat the back of the new amplifier with silicon grease, Dow Corning MS4 or similar does the job. While you're in there with the dizzy out, do a resistance check of the pins from the ignition pickup and also check the baseplate moves correctly in response to vacuum (suck test). You can also check the distributor generally for condition and that the shaft rotates smoothly and doesn't have excessive play.

As already said, there is no control of the ignition circuit by the EFI ecu. The fuel injection system is quite basic and the only connection between fuelling and ignition is the coil feed that tells the ecu the engine is running.

As you have said you are losing voltage to the coil I would suggest looking carefully at a couple of things. 1 - The two pin connector on the ignition amplifier, the wires can (and do) go brittle and break but you can't see the damage, wiggling the wires works for a while but eventually you'll end up cutting off the connector and putting on a couple of crimp connectors. 2 - Carefully open the loom under the bonnet, trace the wires between coil and ignition amplifier. You will find there is a splice on one of the wires, can't remember if it is on the white wire or the white with trace wire but either way, look at the splice, it may need cleaning up.

Apart from that, really you only need to do some basic voltage and continuity checks to map and test the ignition circuit, it is not a complex system. HTH

When I take my dizzy out I use white paint to mark the join of the dizzy base to the top of the block.
Then with the cap off another dot on the tip of the rotor arm followed by one on the edge of the dizzy - the bit where the cap sits.
Then as I carefully remove the dizzy & the rotor arm finishes rotating another dot on the edge of the dizzy to line up with the one on the tip of the rotor arm.
Makes it so much easier when you refit it.
Clean the dot off the tip of the rotor.
Very easy to get the dizzy a tooth out. Guess how I know.

If you want to remove the rotor arm you MUST press down with something on the reluctor (the 8 point star shaped thing under the rotor arm) as you pull upwards or it's highly likely you'll disengage the auto advance/retard mech springs in the bowl of the dizzy under the plate. If the rotor is really stuck probably better to break it off.
Not mentioned in any of the manuals. Check by turning the arm with your fingers, When released it should spring back to its original position. If it doesn't likely the engine won't run - might pop & fart a bit - & you'll need to take the dizzy apart.
Avoid the rotor arms where the metal is riveted to the plastic.

Ratae said:

When I take my dizzy out I use white paint to mark the join of the dizzy base to the top of the block.
Then with the cap off another dot on the tip of the rotor arm followed by one on the edge of the dizzy - the bit where the cap sits.
Then as I carefully remove the dizzy & the rotor arm finishes rotating another dot on the edge of the dizzy to line up with the one on the tip of the rotor arm.
Makes it so much easier when you refit it.
Clean the dot off the tip of the rotor.
Very easy to get the dizzy a tooth out. Guess how I know.

If you want to remove the rotor arm you MUST press down with something on the reluctor (the 8 point star shaped thing under the rotor arm) as you pull upwards or it's highly likely you'll disengage the auto advance/retard mech springs in the bowl of the dizzy under the plate. If the rotor is really stuck probably better to break it off.
Not mentioned in any of the manuals. Check by turning the arm with your fingers, When released it should spring back to its original position. If it doesn't likely the engine won't run - might pop & fart a bit - & you'll need to take the dizzy apart.
Avoid the rotor arms where the metal is riveted to the plastic.

Click to expand...

When you refit the rotor arm put a smidge of vaseline on the spindle, it'll stop it sticking so much, as it shouldn't get that tight ...

Wow, thanks everyone.

Today I ordered a new amplifier based oin your advice and the tests I performed. As will let you know how it goes!

New amplifier is good.
It would be worthwhile checking the rest of the ignition system though. So have a look at leads, plugs, rotor arm and dizzy cap
These motors don't like aftermarket ignition parts. I don't think you can get OE amplifiers but the Intermotor ones seem O.K. For rotor arm and dizzy cap it has to be Lucas - expensive (relatively) but worth it. The same for vac advance unit.

Good luck, let us know how it goes.

Fingers crossed!

JJHawk said:

Hi All,

I have a bit of an issue with my Range Rover Classic 1989 (3.9L V8 Auto) Vogue. In short the car starts first time, but if I have the bonnet down after about 5 mins the engine cuts out. After making tests I have discovered that the voltage to the ignition coil vanishes. I am wondering if something is overheating to make this happens but wondered if anyone had any tips?

Looking at the wiring diagram I guess its one of the following making the issue.

-
ECU connector (1) pin 39
Cable - white/black
Coil(16)
Cable - white/blue
Engine harness connection (41)
Cable - white/blue
Fuse C3 (42)
Cable - white
Ignition Switch (9)
+

Click to expand...

Amplifier on the side of the distributor

JJHawk said:

Wow, thanks everyone.

Today I ordered a new amplifier based oin your advice and the tests I performed. As will let you know how it goes!

Click to expand...

Genuine Lucas amplifier’s are available STC1184G.
I hope a faulty amp is your issue, the amp picks it’s 12v is supply from the coil which u say “the voltage to the ignition coil vanishes”