1993 3.5 V8 discovery running problems

I'll try that with the AFM and see how we go. Defo gonna invest in one of those fault code readers though! Look an awesome bit of kit. How would I go about stopping the dizzy coming out of time? Or is the engine timing your talking about? I'm trying to find someone who is relatively local to me who knows them well. Everyone seems to be massively into 200tdi's around here. Need some v8 advice badly. Would pay well haha!

Joe Edwards said:

I'll try that with the AFM and see how we go. Defo gonna invest in one of those fault code readers though! Look an awesome bit of kit. How would I go about stopping the dizzy coming out of time? Or is the engine timing your talking about? I'm trying to find someone who is relatively local to me who knows them well. Everyone seems to be massively into 200tdi's around here. Need some v8 advice badly. Would pay well haha!

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Dizzy and engine timing are one and the same. I'm new to the area so don't know who knows what's what on V8's. I think there is a guy in Debigh but not sure.

I've done a lot of work on mine over the years. I'm happy to share what I know; stripping, checking/testing and refitting injection and ignition isn't that bad.

How many miles has the engine done and does it have cats?

Gen dealer ignition parts are gash becarefull what you are fitting at the moment iam trying a new source if they are good will let you know
Start with the basics ignition timing.
Base idle
Afm base setting if it is not equipped with lambdas

Yes it was me that had magical dizzy movement, still not figured out how because externally it clamped tight. Was running fine and then within 30 seconds started spluttering, then died and wouldn't restart. Got towed home after 4 hours trying, then eventually found the problem. Had only just set dizzy few days before so didn't suspect it!

I have had many situations on my 92 3.5 where it has been super rich and wetting the plugs and generally not running, but tbh I've not had major misfire.

Have had the regular misfires that have always been ignition but not usually a difficult fix. New plugs and this last time I had to check resistance on all my leads til I found a couple that had fouled terminals.

If its missing on one whole bank it could be injection. Remember 14 cux bank fires so it could be a bad earth to one bank of injectors, bad wiring/connections or possible bad ECU.

I would take all plugs out and rest on the rockers, turn off the lights (or at night) and spin over, can you see a spark on all 8? Make sure every plug is earthed off the engine nicely.

If spark looks good then check timing, if not then obv check over ignition system...

vougese39 said:

Gen dealer ignition parts are gash becarefull what you are fitting at the moment iam trying a new source if they are good will let you know
Start with the basics ignition timing.
Base idle
Afm base setting if it is not equipped with lambdas

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are the genuine ones ****e as well now? I did wonder how long it would be as its just re boxed **** part a lot of the time with landy bits.

so if they are ****e too where do you now go, bosch?

is the manufacturing done here fett though ,whats left of british industry,lr went to bosche a good while ago ,must have effected lucas

not entirely sure what you are saying James, But I am sure its good

as i cannot advetise on here all i will say is i am having my own parts produced

ahh I see , I wasnt really asking - more just expressing Disgust at how ****e gen parts can be for the cost and that there are few options. the p6 boys I know have been forced to use intermotor as the gen rover ones have been so bad for a while or unavailble.

I have been stockpiling used dizzys from ebay which come with gen old caps in good knick for less that half the price of a new gen cap.

Checked all the injectors all good. Checked spark all good. Did notice a little black Lucas connector that connected 2 wires near the afm. They seem to join the same loom as the afm. There was a massive amount of resistance in the connector. What are these wires for? The are white with a black stripe and like I said are close to the afm. There is a wire for the coil right next to them aswell.

Have we decided if the engine has cats/lambdas yet? I can't seem to see any answers in this thread yet. I would suggest checking the lambdas and the connectors, because my '93 3.5 had pretty similar symptoms to this, and I had done similar things as have been suggested before finding out that it was just a problem in the wiring of one of the lambdas (broken connection).


If this has been covered already I do apologise.

Joe Edwards said:

Checked all the injectors all good. Checked spark all good. Did notice a little black Lucas connector that connected 2 wires near the afm. They seem to join the same loom as the afm. There was a massive amount of resistance in the connector. What are these wires for? The are white with a black stripe and like I said are close to the afm. There is a wire for the coil right next to them aswell.

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The white wire and white with black stripe are the coil feed and the injection trigger wire from coil -ve; if that wire is broken or disconnected your injectors won't fire because the ECU won't see the ignition pulse. If the other one is duff then same thing as coil not getting feed to LT side. (Assuming we're talking about the same wires)

discool said:

Is this when the engine is hot or cold? did the engine restart after you cleaned the plugs?
It could be as as simple as a faulty engine coolent temp sensor informing the ECU that the engine is cold although it is hot or more serious it could be a faulty ECU.
I assume the engine is in a good service order and ignition system is ok fited with genuine parts and air filter is clean.

The ninth injector is what my 1987 3.5 had it was screwed in to the left side of the plenum chamber and operates injecting neat fuel into the plenum on cold starting which IIRC was somewhere around -20c so something not used much in the UK, you may or maynot have this injector on your year of engine.

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Hi there sorry but the post from Joe that your post here is replying to is exact same problem my partner and I are having with our 93 land rover discovery. When I read it to my partner he told me that ironically every now and then then the thermo fan cuts in when the motor hasnt even been running or is cold so I'm guessing it's a faulty engine coolant temperature sensor ??