grrrrr timing mark is leaping about..

912uk · Post by **912uk** » Thu May 17, 2007 7:12 pm

Oh joy... fitted the new SUPER, great, out of this world, the one and only... RSR 012 disy.. and it's er............. ok..

Interestingly the timing mark is leaping about like a lune.. and I am not sure why .... Chris did speak about carb settings so i will have to call him tomorrow..

interesting that the revs take a while to drop off with this disy..

any one have any idea how this timing mark is wayward..

Gary71 · Post by **Gary71** » Thu May 17, 2007 7:26 pm

Timing marks jumping about is usually the points arcing, or maybe wear in the distributor shaft so the cam is wobbling changing the timing slightly. Is that gap correct?

Other than that have a look at the vacuum advance, pull off the hose and see if it stabilises.

Good luck

Gilbert '71 T · Post by **Gilbert '71 T** » Thu May 17, 2007 7:32 pm

Bugger

Gary71 wrote:Timing marks jumping about is usually the points arcing, or maybe wear in the distributor shaft so the cam is wobbling changing the timing slightly.

exactly what I thought Gary when I saw Mark's mark yesterday evening

This RSR 012 that Mark has just installed is brand new....

there is an answer out there to this I'll have another think.

912uk · Post by **912uk** » Thu May 17, 2007 7:56 pm

hmmm I set the points up to .3mm idle is set to about 850 but it leaps about..

alarming thing is.. now.

I drive down the road and the car is say at 2000rpm 30mph and all I can here is chuffing..

grrrrr.....

Airhead · Post by **Airhead** » Thu May 17, 2007 7:57 pm

I was never sold on the RSR0012 dizzy since it starts life as a brazilian 009 (and costs 4 times as much) and I've never seen one of those follow the same advance curve twice on pulling the throttle on a VW engine, the shaft always seems to have too much end play out of the box! I've never had the patience to try shimming one up (on a vw the stock vacuum advance dizzy works better anyhow). If such flaws are not ironed out in the transformation process from 009 to rsr0012 then I guess its your call as to whether to send it back or shim it up and see if that makes the difference. Bit of a bodge but a pertronix kit would also provide a work around too if this is the case.

I'd be interested to hear what you find.....I was lucky to find a NOS 050 at a good price for mine but might be tempted if I were persuaded that expense was worth it.

Gilbert '71 T · Post by **Gilbert '71 T** » Thu May 17, 2007 8:08 pm

I run the 0012 with no problems at all, feels just so right for the motor

I feel for you mate I know how frustrating troubleshooting these things can be I was begining to wonder if it was a problem with the actual timing light... I wish we'd tried using mine last night as well.....as a second opinion and all that

I'm stumped as to what it can be...also wish we'd listened to what Chris mentioned about the carbs possibly causing it, try pm'ing him (butzsi) for further clarification also might be worth taking a brave pill and running a compression test, just to satisfy yourself.

912uk · Post by **912uk** » Thu May 17, 2007 8:20 pm

yes I can do that as well would be good to know for sure ... at the end of the day it's a temp engine.. if it continues then I am going to stop drive it local and then rebuild the orginal one..

Airhead · Post by **Airhead** » Thu May 17, 2007 8:24 pm

0.4mm is normal setting for the points gap assuming no wear on the cam, this should give 50 degrees dwell angle, acceptable tolerance is +/- 2 degrees

912uk · Post by **912uk** » Thu May 17, 2007 8:38 pm

interesting I work from the Genuine Porsche 912 workshop hand book and it says .3 ......so i just checked out my other book and it says.. .4

ok I know 100% the points gap on my 050 is .4 so I will do that now..

Graham · Post by **Graham** » Thu May 17, 2007 9:15 pm

You say the rev's drop off slowly,this could be due to the mechanical advance springs being softer and taking longer to return,ive used one of these and it was ok,but we get our 009's modded here in the UK and they work great!

912uk · Post by **912uk** » Thu May 17, 2007 9:18 pm

well it could be me BUT... I have now increased the points gap to .4 and it seams to drop fine now.. and also it doesn't seam to pop and bang as much or certianly as strong as before..

very odd..

I am going to redo the valves tomorrow morning.. start all over again just to make sure it's all right..

Airhead · Post by **Airhead** » Fri May 18, 2007 9:43 am

Dont forget the timinng will have changed too now you've reset the points gap so that'll need adjusting again too

I guess with a smaller points gap, the points having remained closed for less time to charge the coil and you'd have a weaker spark in theory....though I'd not expect this to be enough to cause a problem on a 4 cylinder car and especially not at idle but 0.1mm is definately enough to take you outside the +/-2 degrees tolerance for the dwell angle

912uk · Post by **912uk** » Fri May 18, 2007 10:05 am

yes lots to look at now and I have got some checking to do I am confident I can get this sorted.

A very valid point has been raised by one of the 356 boys in the US.. I need to do some checking ... as there could be some missing parts in the area under the disy... he has had the same problems him self and as I didn't build this engine I have to take the Harry Pellow rule book out and think that some VW turkey did it and missed off a few bits..

impmad2000 · Post by **impmad2000** » Fri May 18, 2007 10:29 am

I don't know what you pay for a fancy dizzy, but a crank fire, distributorless system could cost <£200 and possibly nearer £120 if you are prepared to grub around in a scrap yard.... Just a thought ! It absolutely transformed my Imp
(I'll shut up now Darren

)
Tim

912uk · Post by **912uk** » Fri May 18, 2007 10:35 am

I think it was about £110-120 with the exchange rate which is good at the mo..

anyway I think now I have got it down to a few points

one of which is the fact that the plug on number 4 os sooted up and all the others are spot on .. so hence what Chris Turner was saying is the fact that could at low rpm's be giving you a bouncing reading from the no 4 cylinder which in affect is will put the car off balance. Which I agree with as I showed Darren the no 4 plug on Wed and said now that don't look right..

So I am going to recheck the valve clearance ESP no 4 and also do a compression check then I am going to clean the plug and see how it goes from there..

also the other 3 cylinders I am going to richen then up a bit 1/4 turn at a time and see if it stops this

BTW thanks Chris for your time..