Help ! Vacuum advance broken from distributor- Pre Cat Griff

[Mickygee]

Have a 92 Pre Cat 4441 BV Griff.

Noticed the engine wasn't as keen to rev as normal and as strong as a shove higher up the rev range

Was checking things out on the engine and noticed that one of the screws on the vacuum advance had fallen out and the other screw had come adrift together with a piece of the ditributor (I assume its a threaded swaging although it could be part of the dissy body).

On wiggling the unit the vacuum came adrift from the distributor.

Is this a straight forward fix or am I looking at a replacement dizzy ?

I am guessing this is the cause of lack of high rpm urge too................

Edited by Mickygee on Sunday 16th August 18:05

Edited by Mickygee on Sunday 16th August 18:14

[GreenV8S]

There should have been two screws securing the vacuum unit to the dizzy - is the second one still OK?

Don't recall seeing a separate boss for the screw to thread into but maybe it's standard, or perhaps somebody has stripped the thread and added that as a repair. I would think your best bet would probably be to clean up both parts and try to glue that insert back into its hole.

I've got a couple of spare dizzies here somewhere and I'll have a look later to see whether these inserts are normal.

[Mickygee]

One has fallen out and disappeared, the other has come out with a bit of dizzy attached.

If I glue the insert in I guess I'll have to take the dizzy out to rehook the vac advance back on to the distributor. Or can it be done in situ ?

Also I will need another screw any clues on size or source ?

Cheers

[GreenV8S]

I've had a look and found that these dizzies do indeed have steel inserts for the screws. They're pressed in from the inside and have a large (8mm ish) hex shaped flange on the back which should stop them pulling through. Perhaps the inserts on yours are different because the one in the pic doesn't look that big.

I'm not sure how you're going to repair that. You need to replace the insert, and to be reliable I think the replacement needs to be pushed in from the inside, and that's not something I'd fancy trying with the dizzy installed. Getting a suitable insert might also be tricky and it might be more sensible to fit a captive nut.

Distributors aren't very expensive second hand and another option if you're willing to strip and reassemble the dizzy yourself is to buy a spare and move the guts from your one into a replacement shell.

Having replaced or repaired the dizzy, it's possible to reattach the advance module to the baseplate inside the dizzy with the dizzy fitted, you just need to hook the arm on before fitting the screws.

In the meantime to keep it running all you need is something to physically hold the vacuum unit tight against the side of the dizzy, and there are various ways you could achieve that using lock wire, jubilee clips etc.

To fix this properly is going to be much easier if you take the dizzy off, but before you do that make sure you know exactly how to reinstall and retime it afterwards. You need to check the actual timing at the crank pulley, mark the exact orientation of the dizzy body relative to the front cover, and mark the orientation of the rotor arm as you remove it (bearing in mind that the rotor arm will rotate slightly as you withdraw the dizzy). And of course you need to remember what the orientation of the dizzy cap and leads is.

[Mickygee]

This dizzy came from my original 400 engine which had done over 90,000 miles. Is it worth fixing as its so old (although until recently its been fine)and just go for a recon one ?

Is this a stock SD1 EFi dizzy or did TVR make sppecials ? Recommended supplier ?

Thanks for the advice.

Mick

[Mickygee]

Are these any good anyone had experience of them ?



Rover V8 3.9 3.5 Lucas type 35D Distributor MG TVR ..
http://cgi.ebay.co.uk/Rover-V8-3-9-3-5-Lucas-type-...

Or am I best sticking with genuine lucas if I cant fix ?

[GreenV8S]

Looks like the right sort of thing, but find out what sort you already have fitted first. Is the ignition module mounted on the dizzy? Is it a 2-pin or 3-pin module? Is the position of the ignition module relative to the vac advance the same?

You will need to either confirm that the mechanical advance has the same characteristics, or dismantle both units and swap the springs and weights over. Are you prepared to do that?

[Mickygee]

Now you are starting to frighten me..............

How do you get a distributor with the right mechanical advance for a Griff.

Distributors arent something I've pulled apart before.

[dwgriffith]

Mickygee said:

Are these any good anyone had experience of them ?



Rover V8 3.9 3.5 Lucas type 35D Distributor MG TVR ..
http://cgi.ebay.co.uk/Rover-V8-3-9-3-5-Lucas-type-...

Or am I best sticking with genuine lucas if I cant fix ?

That eBay one is the same as supplied by several other big names. They are copies of the original Lucas units, the three (from different suppliers) I purchased and returned were all the same. They all had more play in them than the original I was going to replace, they apparently work OK but none of them were very well made? two of them had swarf under the covers attached to the magnets(not a good sign). Two other things, the ignition amps are unbranded and the vacc advance is unspecified, does it matter? your guess is as good as mine. I ended up building one out of NOS Lucas genuine parts off eBay for less than £50 in total.