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Shims under my dizzy

Posted: 07 Jan 2009, 16:16
by albertramsbottom
Should have them, becuase i dont think I have :shock:

https://club8090.co.uk/forum/viewtopic.p ... +#p7306352

Cheers

Re: Shims under my dizzy

Posted: 07 Jan 2009, 20:54
by dugcati
can you/someone post some pics of the shims? I am very interested to see this as I have never heard of shimming a distributor before

Re: Shims under my dizzy

Posted: 07 Jan 2009, 21:03
by Aidan
they are thrust washers, as a pair and the bottom of disidriveshaft and the case are seperated by them, otherwise the soft alloy case would be worn by the seriously hard disi drive shaft and you'd have all sorts of problems. I wouldn't worry unnecessarily, unless you have some reliable indicator of a problem with the disi drive. And a disi shaft with a bit of float in it doesn't necessarily mean the shims are missing, more likely the fibre washers in the disi shaft stack itself have disintegrated over many moons of life in a hot place wizzing round really quick, only very very rarely will the rotor arm do any damage internally to the disi when the shaft floats a bit more than vw intended, but it does happen and it happened to me once, rotor arm and hall sender had a coming together, rather lost spark after that :cry:

Re: Shims under my dizzy

Posted: 08 Jan 2009, 09:13
by ermie571
Hi folks....firstly, thanks to Aiden for clearing up shims and thrust washers.

Symptoms that led to this....to make it absolutely clear!

Completely unable to get a regular, even, steady idle........as the engine would rev anywhere from 1000 - 2000 revs. Bit like an air leak, but extreme, and variable. Engine appeared to be HUNTING but altering the mixture made no difference. When driving on LPG it would hiccup and miss randomly, but no backfire. On petrol, although it didn't hiccup it was running as if the power was there.....but couldn't access it somehow....again, timing.

Also....my dizzy was 180 degrees out (bought like that as a replacement engine, not as rebuild), and I was having to buy 2 sets of leads all the time! Until the hiccupping started, it had been fine.

So, when it went in for a service to get the gas system balanced, I asked Elite to change the dizzy round as well. They serviced the gas, changed filters etc etc, and when they fired it up to check, it was even worse on the erratic idle. Popped the lid on the dizzy, and waggled the rotor arm......is this what is meant by float?...You could moive it up and down, and left right a bit as well, Mick didn't look impressed, and removed Dizzy. Thought initally the distributor was furbarred.....rotor arm too loose and damage to suds underneath. But then investigated the drive....and no shims. Big Mick removed the drive, turned it through the 180 degrees, inserted said washers, and refited the dizzy, hoping that the shims would cover the damage on the case. Little Mick tried the rotor arm....much firmer. He was able to set the idle, and it is now driving well again, with no wild idle.

According to Mick, in laymans terms the dizzy was loose in the drive, and was changing the timing all the time. Also explained the poor running on petrol... :wink:


Hope this helps

Emma

Re: Shims under my dizzy

Posted: 08 Jan 2009, 10:20
by Aidan
nice explanation Emma.
yes that's what I meant by float, there should be some but there are a couple of springs and some fibre washers that take up the float and damp it so that the rotor arm spins in a flat plane. (there's a small spring between the disidrive and the disi for example)
In your case at it's worst the blade end of the disi was popping out of the slot in the disidrive and the disi slowing down then catching up again hence rough running
its would have been clear when trying to adjust timing that disi was running erratically, it's the determining why that was the MickTrick, little Mick I reckon :ok

Re: Shims under my dizzy

Posted: 08 Jan 2009, 10:52
by albertramsbottom
I belive after your descriptions that my dizzy has got these.

Are they about an inch from the bottom of the shaft, insofar as they separate the bottom of the shaft from the top?

Cheers

Im getting there

Re: Shims under my dizzy

Posted: 08 Jan 2009, 11:24
by ermie571
Aidan wrote:nice explanation Emma.
its would have been clear when trying to adjust timing that disi was running erratically, it's the determining why that was the MickTrick, little Mick I reckon :ok


Aiden,
thanks for that....nice of you to say so!

Yes...was Little Mick.....only needed Big Mick to get the drive out, and put it back in.

You know them well.... :D

Em
x

Re: Shims under my dizzy

Posted: 08 Jan 2009, 11:30
by ermie571
Aidan wrote:nice explanation Emma.
In your case at it's worst the blade end of the disi was popping out of the slot in the disidrive and the disi slowing down then catching up again hence rough running


Bang on....that's exactly it!! The bottom of the dizzy has two studs, rectangular, that slot into the drive in the engine You call this the Blade end!. Both Stud (blade) and slot were showing damage. L/Mick reckoned it was jumping out, which was the hicuuping, and erratic idle was when it was loose, and slowing down, catching up as you describe. B/Mick thinks that I will be ok now, as the washers seem to have tightened everything up again, and with them in place, it is hoped that no further damage will be done. But at least I know what to look for now!

Thanks for making the penny drop!

Em
x

Re: Shims under my dizzy

Posted: 08 Jan 2009, 11:35
by ermie571
Albert,

not sure what you mean here. But the shims are not on the dizzy...or they were not in my case. The fitting was as follows....
1. Place distributer drive in engine
2. Place washers in drive
3. Place distributer in drive

So, the washers sit between drive and distributer.....not sure whether they would come out with the distributer when you remove it. Maybe a picture would help?

Em
x

ps - keep asking the questions......I am! And I post up anything that seems interesting to me......in the hope that it may help someone, somewhere!! Don't think I will ever "get there" though :( Aiming for half way!! :D

Re: Shims under my dizzy

Posted: 08 Jan 2009, 18:56
by Aidan
thrust washers go in the case first, slid down a screwdriver blade so they don't fall sideways into the crankcase and foul and or be lost.(big er er, quack quack ooops that btw)
Once they are in place they can't fall out sideways and the bottom of the disi drive will pop through them fairly readily. But any in and out faffing and then one or both can get picked up on an oil film on bottom of drive as it's withdrawn and then dislodged and drop off into case unseen.

Then the disi drive goes in with it's little spring on top, with the engine timed to #1compression ignition stroke and drive set accordingly, see diagram in haynes, and the disi is set to the same timing mark, then the disi is inserted into the drive whilst locating the securing ring on it's stud, there's a little trick to the disi insert as there's a little insert twist insert movement involved, getting the alignment so it all slips in just so; timing checked again, add rotor arm dust shield cap leads etc then engine should start and run and final timing and idle adjustments can be made.

Re: Shims under my dizzy

Posted: 08 Jan 2009, 19:20
by ermie571
Now that ^^^^^^ needs to be wiki'd.....

and the two Micks had the washers, dizzy in and timed and running in minutes.... :shock:

Aiden, great write up :D