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Hi Guys so last month I had a recon starter; dizzy and carbby fitted to my 4k rolla. all good when i received it it started right up and drove like a fuel injected rolla :rocknroll: . i had a timing light of a friend and it was set to just under 20 ? so i did not pay any attention to it as the car was running fine and started with a touch of the key.

now a month later that feeling of fuel injection is gone and its back to its old ways again. need a kick start in the morning and only turns over when the motor is fairly hot. On saturday past i added some valve ease to a half a tank of fuel so half a bottle af valve ease then

this morning I kick started as normal when I noticed a miss on the engine when i rev it, on idle it all good but as soon as i pull away it shudders and gives of a miss and backfires though the exhaust then when the revs get a bit higher its ok again until i change gear the the same shudder and revs go higher ok again. :down:

 

is this the timing, vacume advance, carbby or how do I go about fixing this as I just spent alot on these recon parts. I checked the plugs on idle for a bad one by pulling them one by one and each one I pull it idle's rough put back normal like it should be. point and condensor I am not keen on as I don't know much always let someone do it for me. :hammer: :bash: this car is starting to cost me more than what it is worth.

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Ah, you should have set the timing correctly when you had the light, then you could check it now & see if it has moved.

 

So, factory set is 8deg at idle with vac disconnected and blocked. In reality the vac should make no difference at idle anyway. Then if you rev it the timing will max out at 36deg by 3000rpm.

 

Now if it was running fine when you put it back together something has changed. Check the points, are the tight enough or were they left a bit loose. The screws just have to hold the plate in place, not very tight, but check the gap to see if it has shrunk. They were new points I assume, and you always replace the condenser when you fit new points.

 

Is the dizzy tight?? Same thing, that 12mm bolt head just has to lightly grip the dizzy enough to make sure it doesn't move.

 

Did they put a touch of grease on the points rubbing block so it doesn't wear away by running dry on the dizzy cam?? Usually that takes a few months.

 

Is the ballast resistor correctly wired up?? Did you have it disconnected during the work? It knocks the "run" ignition feed down to 9volts for the 9volt coil, and it gets by-passed when you crank the motor on "start' so it lets the full 12V to the coil. It gets hard to start without it doing that.

 

Grab that light again and check the idle timing then watch the light when you raise the revs a bit. Pull the vac line off at about 1500-2000rpm and see if the timing retards so you know the vac advance is working.

 

Grab a compression gauge and check the compressions, and grab that R10 Chinese electric test meter and see if all the leads have the same resistance.

 

Inspect the dizzy cap for cracks or carbon trails, unless it came new with your dizzy. Coils are harder to test, maybe somenoe has a bench tester to see.

 

It sounds like it is misfiring under load at low revs, then clears when it really gets going. I reckon electrical rather than fuel, but who knows?

 

Once you have solved all the problems you have learned so much you never need to pay a mechanic!

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will try this tonight when I get home please send me the points gap as i am going to buy me a feeler gauge and new points and condensor, for the ballast resistor that thing is wired up with a whole lot of wires running from it there;s even one wire from it to the black mechinisim on the carbby?

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Ok just checked the timing with the timing light on idle when I drove it from work to home about +/- 15km drive opened up the bonnet and she was running hot checked heat gauge was sitting in the middle normaly it would be just below 1/4 so she was hot timing was at juin between the zero and firts line before rhe dot for the 8 mark so I would say about 2 or 3tried setting it with dizzy but it was already on its max if I turned it away foem the engine timing would go below 0 and make it die so I think when they install it the did it wrong the guy who helped me had one when he was way young that's why he still have all these tools as per him is should just move the dizzy a tooth or two so it can have more movement on that bracket which the bolt ties it down.

 

Any steps for me to follow?

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..and that's why it lost performance.

 

As it lost spark advance it doesn't run as well, and it will run hot. Fit the new points and condensor, and make the gap 0.45mm when the points rubbing block is on top of one of the shoulders of the shaft. That is the maximum opening, the time when you set the gap.

 

You will have to rotate the motor with a spanner to get it sitting right. Lots on the web about how to set points. Make sure you are working on cylinder one firing, so take off the oil cap and watch the rockers for #1 as you turn the spanner. When the #1 exhaust closes you have started the compression stroke and the next time the timing mark comes up it is firing #1. The rotor will turn towards the #1 plug lead as you do this. Stop when the pulley notch gets to 15deg or so.

 

Then turn the keys onto ignition and rotate the motor with a spanner until the pulley timing mark comes up to the 10deg mark on the timing cover. Turn the dizzy until the points spark and you will see them start to open. Turn it back and slowly forward until you have it just firing at 10deg and the rotor points to #1 cyl lead.

 

It rotates clockwise, so retarding timing is turning the dizzy clockwise, advancing is turning the dizzy anti-clockwise. Too bad if you've only ever seen digital clocks!

 

That is your ignition timing and it should be at the 10deg mark. Mark the pulley notch with white paint so it is easy to see, and mark the 10deg & zero on the cover. If you can get it right then re-assemble it, run it and check it with the timing light. 10deg at idle, no vac tube on.

 

If you can't rotate the dizzy enough, you'll have to rotate it a tooth. Let us know if you have to do that & we can tell you how.

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Allow me to ask a question. I'm running the carb of a KP61 Starlet and since I don't know where to connect the dizzy vacuum advance tube on the carb I connected it directly to the manifold.

When setting the timing, when I unplug the vacuum tube the engine stalls. Why does this happen?

I just set the timing with vacuum on, I'm running around 12 degrees that way and it goes pretty well.

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dude you need to block off the advance when setting the timing Disconnect the hose and block it off the car should Idle as the vacuum advance only kicks in when you rev it.

 

higher. thus I think your timing is out or your idle mixture is not right.

 

Back to my prob i set timing gapped the points and all ok now.thx guys

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dude you need to block off the advance when setting the timing Disconnect the hose and block it off the car should Idle as the vacuum advance only kicks in when you rev it.

 

higher. thus I think your timing is out or your idle mixture is not right.

 

Back to my prob i set timing gapped the points and all ok now.thx guys

 

Totally wrong. .... vacuum advance is pretty much only for idle and light throttle driving. As you rev the motor and open the butterflies you lose vacuum, at what you essentially shouldn't have any!

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All good then-

 

The difference in the vacuum is that ported vac on the carb is blocked off at idle, then the moment you open the throttle a touch it gives a signal. With throttle wide open the signal dies.

 

With manifold vacuum the signal is strongest at idle, so it gives lots of advance then. On part throttle it gives less advance, and gives no advance at full throttle.

 

It was all designed to add advance when cruising, as such small throttle applications meant little fuel being burned and more advance gives it time to scavenge the pockets of fuel in the cylinder & reduce emissions. If you boot the car to overtake someone the advance falls off to stop it knocking under full load.

 

Manufacturers usually call for timing to be set without vac connected, and at idle the weights are not working either, so it is a real baseline figure you set it to. Then vac advances it at idle or just above, and the weights take over at about 1200rpm to advance it up to 2500rpm or so.

 

You can set it to suit the fuel and the altitude you drive with. If you measure some accleration times and accurately check your L/100Km you might end up with more advance than factory. The 4K runs happily on 18deg or more at idle, but then it won't like 50deg max advance.

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