The V8 Owners Forum -

hey guys in my attempts to sort out another problem i messed with my ignition timing on my 95/M 3.9 v8 discovery...

i've reset it, using a timing/strobe light to bang on the timing mark (crank pulley) but she feels a little "down on power" not as responsive now when running on lpg (which i do almost all the time, petrol is just used for start-up)

can anyone suggest a good ignition setting for optimum lpg running, bearing in mind all i can find is a large 'notch' on the timing/crank pulley???

cheers muchly, welshy

If you clean up the pulley there should be timing marks.

I run my RR Classic 3.9 on 16 deg BTDC base timing for LPG with vac disconnected.

16 deg is beyond the std timing @ 12 deg, I use a paint marker to mark TDC and the timing marks

cheers...

reet time to get me emery/sand paper out and have a good ole clean up!!!

Once you've uncovered the markings, smear a bit of tippex over them and then wipe off - should leave the marks bit more visible

I used to just turn the distributor until I was happy with performance......

Chris.

I also used to do what Chris suggested.

Turn dizzy to advance a bit, then go for a drive ON PETROL. Make sure that the thing is not pinking like mad.

Keep advancing until you are only getting a tiny bit of pinking under heavy load on Petrol. I had mine set so that I could drive around any pinking on Petrol just by shifting down if needed.

Now you have set the timing as far advanced as possible to run LPG, without making the car unusable on Petrol either.

i'd like advance more but the vac pipe off the dizzy touches the fan belt by the power steering pump...

welshphill wrote:i'd like advance more but the vac pipe off the dizzy touches the fan belt by the power steering pump...

The distributor is probably one tooth out on the camshaft then.

Chris.

MMMMmmmmm

when i first picked it up the dizzy cap was on backwards so i suspect the last person to touch her was a bit of a bodger/didn't have a clue...

how would o go about getting the dizzy spot on???

welshphill wrote:MMMMmmmmm

when i first picked it up the dizzy cap was on backwards so i suspect the last person to touch her was a bit of a bodger/didn't have a clue...

how would o go about getting the dizzy spot on???

The technique I use is this:
1. Get the engine to TDC on no. 1 on the firing stroke. You can get it to TDC with a screwdriver in the spark plug hole. You check it's on the firing stroke by making sure that both valves on no. 6 are open a crack (you have to remove the rocker cover to do this).
2. Fiddle about with the distributor / oil pump drive until when the distributor is fully home, (it turns as you slide it in), the little spoke on the 8 spoked thing is pointing exactly at the little spiked pickup. Also check that the distributor is in the middle of it's adjustable range, i.e. not hard up against the water pump or head.

Then turn the distributor body a tadge clockwise, put it together and fire it up. Then you should have enough adjustment.

Also make sure you've got the right sort of distributor. I forget whether the SD1 version means you have bugger all adjustment on a Range Rover, or the other way around, but it's worth checking.

Chris.

can you not work out that no. 1 is on the firing stroke by checking if the rotor arm is pointing at least vaguely to where the HT lead for no. 1 would be? this would save taking the rocker cover off.

spratty wrote:can you not work out that no. 1 is on the firing stroke by checking if the rotor arm is pointing at least vaguely to where the HT lead for no. 1 would be? this would save taking the rocker cover off.

Yes.

If the dizzy is out and you don't know which stroke you're on, just take out plug one and turn the engine with a ratchet handle on the crank bolt with your thumb over the hole - you'll feel the compression.

two top tips....

will do it this weekend

thanks guys, as always great advice

welshphill wrote:MMMMmmmmm

when i first picked it up the dizzy cap was on backwards so i suspect the last person to touch her was a bit of a bodger/didn't have a clue...

how would o go about getting the dizzy spot on???

don't use bodger and havn't a clue in the same sentance please ... lol

if you have a look on chris's brillant website , there are a few differant types of dissy and the vac is in a slighty differant place , could be another reason why it won't turn far enough ..just a thought ?

The one on the left is Range Rover, the one on the right is SD1.

Chris.