126 replies to this topic

[KernowCooper]

I would increase the air gap on the trigger a bit once your happy with the secure of the components

[The Freak]

How would this help? 

[KernowCooper]

The hall effect trigger is a semi conductor switched by the effect of a magnetic rotor the black ring, just seeing if the trigger unit is is being affected by stray magnetic fields off the other 3 firing points on the black trigger ring, which would switch the coil at a different time that what you set the timing to. By increasing the air gap between the semi conductor and the black trigger ring would lessen the chance of stray magnetic interference affecting the timing/

 

Its got to be something really odd now as all of the normal thing have been tried.

[KernowCooper]

You dont have a set of points and a condensor to test in it do you ? this could indeed point towards a duff hall effect trigger

 

I know there are 2 members watching this post with the same problem, so can someone remove the baseplate and check for correct operation of the advanve mechanism as any maching errors causing this to bind and not return would cause the problems described here

Edited by KernowCooper, 24 June 2013 - 12:26 AM.

[KernowCooper]

I have spoken To Simon at Powersparks this morning and hes has asked me to ask the to people concerned to ring him on 01527 8894532 and make sure in the conversation you mention my conversation (David TMF) and he will arrange to get the distributors exchanged for a new one

[The Freak]

Morning,

 

Thanks for the support and thanks for calling simon.  Did he suggest what he thought might be wrong?  I had already contacted him when teh first dizzy had this problem about three-four weeks ago.  He got me to send it back and said he would switch it for a new one.  However, I think he just sent me the old one back.  I recognised it from pictures I took before I sent it back.  Whether or not he had changed any parts I am not sure.

 

I feel stupid because I know my round a car engine yet I can't work out what is happening to produce the events listed above.

 

I will call as you suggest and I will post back what info I get.  However, it took a fortnight from me sending my original dizzy back to getting it back in the post and another week before I had time to install it (work comittments etc).  It could be a while before I can tell you whether or not this has resolved the problem.  If anyone else gets this sorted quicker I would be interested to hear what was wrong.

 

The really strange thing when the electronic dizzy was fitted and if I could get it started, was, that it ran beutifully.  Very smooth, no misfires, no back fires.  Felt powerful through the driving range, not sluggish.  It was just I couldn't get it started to get to the good driving bit.

 

Cheers

[lrostoke]

Yours really does sound like you have the wrong advance curve.

 

Sounds like in order to get good running your having to advance so far that your are getting to much advance at static.

 

http://www.jcna.com/...h/tech0015.html

 

May be worth seeing what advance weight is fitted in the dizzy...No should be stamped on.

 

eg if you have a 10 degree weight, this is 20 degrees of mechanical advance which should mean if you have 32 degrees advance @4000rpm ,at static you will have 12 degrees advance

[The Freak]

When you say stamped on it, do you mean on the weights? or on the dizzy body somewhere?

 

What your saying is that when I set up the dizzy to 5-7 degrees of static timing.  It is actually a lot more under dynamic.  What about when I set it  up dynamically?  Iset it up to 5-7 degrees.  Does this actually mean it is a lot more?  If this is the case why isn't this represented via the timing marks?

 

Retarding the timing would help this?  However, when I retarded it the engine began spinning but wouldn't fire.  As I mentioned above, if I could get the engine going it ran perfectly having set the timing to 5-7 degrees (i keep saying 5-7 degrees as the pointers go up in 4's and I am guestimating where 5 is).  It is clealy timed up very well as when running, it is sweet.  It just won't rotate to get going.  Would the advance curve affect it that much just under start conditions, but fall in line during operating/load conditions. 

 

I will have a look when I get home from work.

 

How could it be that I have ended up with the only dizzy from powerspark to have naff weights...just my luck!!!!!!!!

 

Thanks fo rthe advice.

 

How have the other guys with this problem got on?

[lrostoke]

If you set the dizzy static at say 5 degrees then that is the starting point for the advance mechanism.

 

So say you had a 10 degree advance weight in the dizzy and you set the static to 5 degrees ...the most mechanical advance you would get is 25 degrees.

 

If you set the advance at 5 degrees @ 1000 rpm then the weights may already have started moving by then (depending on spring strength) so possible you will already have used some of the mechanical advance giving less at higher revs.

 

Depending on spring strengths in the dizzy, 5 degrees @ 1000 rpm would possibly give less at static..you look in Haynes and where give there is as much as 5 degrees difference between static and strobe timing

Edited by lrostoke, 24 June 2013 - 12:28 PM.

[The Freak]

That doesn't expain why it runs beutifully under all opperating conditions bar starting.  I understand what your saying but how could the weights being wrong stop the engine cranking over.  even if they were set at maximum advance (which I have recorded as 22 degrees) surely the engine would rotate.  When you turn the key it is as though the battery is dead.  You are lucky to get one rotation.  I put a more powerful battery in as I thought it was the battery at fault as the old battery would just click the starter solenoid.  Is this possible it is shorting something out?  I found out there was nothing wrong with the old battery, other than being a little less powerful than the new one.  The problem with hat idea is, why would the engine suddenly spin freely when the dizzy is rotated anti-clockwise (retarding the ignition).  Doens't start up in this situation though.

[lrostoke]

The problem you get if the start advance is to much is the plug fires while the piston is rising, so basically you get ignition and the combustion trys to force the piston back down...basically acting like a brake.

 

what revs did you record the 22 degrees advance at ??? 22 is not a lot.

[The Freak]

Hi,

 

The maximum advance I recorded, with vac connected at any engine speed other than idle was 22 degrees.  Max was about 3000-3500 rpm.  However, when I let it go back to idle with the vac advance connected it stayed about 18-20 degrees of advance.  It was only with the vac advance disconnected that I got 5-7 degrees.

[lrostoke]

It may be worth checking everything is connected in the dizzy

 

I've had a dizzy off Simon and whilst he's willing replace and discount it did have a few problems.

 

Namely vac advance unit was not connected to the base plate. (can discount this based on your last post)

Rotor arm was to long and catching the lobes in the dizzy cap.

 

Sounds like you only have possibly an 8 degree weight in the dizzy, which for a standard engine would be fine, yours is modified so could be whats causing the issues.

 

To get max power you want somewhere around 32 / 34 degrees @ 4000 rpm...for you set up you would be looking at 16 - 17 degrees @ 1000rpm to achieve that. I reckon a 10 or 12 degree weight would sort you out.

This would still give the 32 @ higher revs, but lower your advance to 8 or 12 @ 1000 rpm

 

 

 

 

Edited by lrostoke, 24 June 2013 - 01:13 PM.

[The Freak]

I will have a good look when i get home form work later.  I hope it is something like that.  that would at least make sense.

 

He replaced it once already.  Although, I don't think he did replace it.  I sent the old one back and a fortnight I got it back.  No explanation, but I am assuming he changed something on it?  I could tell it was the same one as I took pics of it and all the marks and nics matched up. 

 

I was trying to save a bit of effort changing points every six months.  It has cost me twice that effort putting dizzies in and out of the engine, not to mention the cost of sending them back and forth, plus the inital cost.  I want it to work and I am prepared to stick with it, but I am getting to the point (pardon the pun) where I am going to suck it up on the points front and bin the electronic ignition idea. 

 

Cheers for the help

[lrostoke]

If you have the original dizzy and it works fine for you, why not send the electronic dizzy back and just buy one of the conversion kits to replace the points in your old dizzy.

 

You still keep all the advance charactistics of the original dizzy but with electronic ignition !!