The V8 Owners Forum -

Right then ... Rover v8 3.5 , efi ... with electronic std dizzy ..

I swapped over the dizzy one that was exactly the same type etc ...but id been cleaning it ... anyway
after changing it over it wouldnt run properly if at all
So i put the orignial dizzy back and still no joy ...

ive checked the timing TDC at correct point of the cycle ..and nothing
The only way it will run in any way is to have it timed ..( according to pulley marks )
At approx 30 or 40 degrees BTDC ...
Any attempt to move the dizzy to line up timing via strobe light results in the engine dying ....
Ive got the rotor arm in exactly the correct place , static timed on TDC ..but wont even try to run unless its way advanced ...????

Please help ... i though the timing chain may have jumped or slipped but ive now got the front off and although the chain is worn theres no sign of the valve / dizzy timing being out

Sounds like you need to move all the plug leads round one place?

Turn the engine by hand until it is on the No1 compression stroke and then to the timing mark. Is the rotor arm pointing at No1 plug lead?

Static timing is fine , ive tried moving the leads round the cap ...it makes no differance
It will run but very badly ...
when i put the strobe on it its so far ahead of the timing marks on the flywheel that even 12 degrees BTDC is at least 3 inches away , any attempt to rotate the dizzy to bring the marks inline and the engine just dies ... ???

bodger wrote:Static timing is fine , ive tried moving the leads round the cap ...it makes no differance
It will run but very badly ...
when i put the strobe on it its so far ahead of the timing marks on the flywheel that even 12 degrees BTDC is at least 3 inches away , any attempt to rotate the dizzy to bring the marks inline and the engine just dies ... ???

You've the dizzy installed wrong. Phasing is also wrong.

Set the engine to firing/compression on cylinder 1 at or slightly before TDC

Install dizzy so rotor arm is pointing directly to the Cyl1 tower for the lead.

And start again.

Remove the nearside rocker cover and watch for the compression stroke of cyl #1.
Use a stick or screwdriver down the plughole of cylinder 1 to find TDC and compare with your timing mark. (If your timing mark tallies then good, if not either ignore it, retest or recalibrate)
Now as steve says, look where the rotor arm is and ensure that its pointing at lead #1

What's almost certainly happened is you've moved the dizzy round a tooth or two on the drive when you changed it.

To set it correctly.

1) Set the engine to 6 BTDC on the No1 compression stroke.

2) Turn the oil pump tang to the ten to four position.

3) Point the rotor arm at the left hand side of the car at 90 degrees to straight ahead.

4) Enter the dizzy making sure the rotor arm doesn't turn until it engages with the gear. Once it has, it will turn and engage with the pump drive.

It should now point at No1 plug lead as shown in my diagram above. If it's a DLM, the amp should be approx at the front of the dizzy.

Thanks guys ..but if you read my posts ...ive done all that ..
The static timing is fine
It just wont run unless its way advanced

i know how to check if its at tdc and if its on compression stroke !

As you have said that you have all the timing correct, could it be that there is a bad wire connected to the ignition amp and moving the dizzy causes it to reconnect????

bodger wrote:Thanks guys ..but if you read my posts ...ive done all that ..
The static timing is fine
It just wont run unless its way advanced

i know how to check if its at tdc and if its on compression stroke !

What sort of timing light are you using? 'Smart' modern ones where you can dial in advance can get confused by some types of sparks.

I can't think of any fault that could give the symptoms you describe.

bodger wrote:
i know how to check if its at tdc and if its on compression stroke !

So do I...doesnt mean I've never done it wrong before...and before...and before lol

The symptoms do sound like rotor phasing is wrong, or as otherwise suggested rotating the dizzy is affecting wiring in some way interfering with the circuit.

Just a thought. For a period I had an old 1976 SD1 3.5 engine in and the distributor was positioned different to my TVR serp. Looking from the front to rear of the engine, the vacuum advance was at 10 o'clock with spark 1 at 11 o'clock and 8 at 12 o'clock, etc. My Serp engine had vacuum advance at 4 o'clock.

May be of help.

if you follow the instructions given above, the location of the vacuum can has nothing to do with the alignment. If the rotor is pointing to the post that connects to the spark plug in cylinder 1 when just before tdc for compression stroke of cylinder 1 - its timed correctly.

Eliot wrote:if you follow the instructions given above, the location of the vacuum can has nothing to do with the alignment. If the rotor is pointing to the post that connects to the spark plug in cylinder 1 when just before tdc for compression stroke of cylinder 1 - its timed correctly.

I can't think of any fault which would show the wrong timing on a strobe triggered by the actual spark - other than something up with the strobe itself.

Just for information, I did find that my 'posh' Krypton timing light - where you can dial in an advance setting - didn't work with EDIS. But my older 'stupid' one does. It also has a direct connection to the spark plug rather than an inductive coupling.

Oddity's with dialback lights only appear with wasted spark type setups.

Straightforward dizzy with a single spark per event, all lights will work as expected unless they're faulty.

I've not read a decent explanation as to why wasted spark should stop such a unit working. I'd expect it to simply trigger twice as often.

However I do know they can given problems, so offer it a possible explanation - this new dizzy may produce a spark which is odd in some way.

Other thing I'd do it set the engine at where the timing light says the spark occurs and then look at the relationship between the VR sensor and reluctor ring. I've set static timing by lining up the VR sensor and ring peak, and it wasn't a million miles out when checked dynamically.