Page 2 of 3

Re: Starts on one rotor (sometimes) wont idle....

Posted: Mon Aug 03, 2015 7:18 pm
by wiggman2030
I would give it a go. I'm not sure what I would bypass. Do you mean the wires from the igniters to the coils or further a field? Also I've got a couple of questions regarding the carb.

First, when you pull the throttle all the way in should the primaries open followed by the secondary valves. On mine even with it fully open the secondaries remain shut. I know that this won't help with the car idling but i'd like to know before I put it back on the car as I seem to remember on the old carb they might have done.

Also where the primaries shut there are little slots to control the idle I would imagine, if you open the valves a little further there is a little hole on one of the openings. Should this be exposed of should it remain closed off?

I'm just waiting for an inlet manifold o ring as the current one split on removal.... I'll have to take some pictures or some video of the car in the meantime to give you guys an understanding of my set-up in hope you guys might find something wrong that i've overlooked haha :D

Re: Starts on one rotor (sometimes) wont idle....

Posted: Tue Aug 04, 2015 12:05 pm
by codge
The Haynes wiring diagram shows a positive feed coming onto the two coils looped together. It's a black wire with white stripe. It comes straight to the coils from the ignition switch and fuses. There is also a small condenser (capacitor) connected between the black/white wire and the body area, shown in Haynes as being at the coils. Keep this capacitor in the circuit but have a good squint at it......looks OK?

What can be done is to simply (with the ignition key out) take off the incoming positive connection at the coils from the ignition circuit and use a flying lead (WITH AN INLINE FUSE - 5A or so) taken from a croc clip on the battery positive. Connect the flying lead to the coils, put the croc clip on the battery +ve and try the starting on the key again.

That will say if the wiring harness - underdash and engine bay - is intact to the coils.

The Haynes diagram is unfortunately only up to Series 2 models but Series 3 should be the same.

Re: Starts on one rotor (sometimes) wont idle....

Posted: Tue Aug 04, 2015 6:27 pm
by wiggman2030
Right I had a look at a wiring diagram for a 83. I'll just confirm this first :)

So the black and white wire comes from the ignition swtich to the leading and trailing coil as well as two wires to the dizzy ignitor and one to a condenser then earth. Are you saying that I need to disconnect the current black and white wire from the ignition coils and run a flying wire from the battery instead, bypassing the ignition circuit? Would I leave the current wire from the ignition to the ignitors and condensor intact?

Re: Starts on one rotor (sometimes) wont idle....

Posted: Tue Aug 04, 2015 7:54 pm
by wiggman2030
Also just to add to the confusion I had a look inside the dizzy. From what I gathered looking at the wiring diagram yellow and blue is leading, yellow and green is trailing. This was the case on my car too but....

I looked inside the dizzy and the leading ignitor (tyellow and blue) actually has a T stamped on the plate within the dizzy connected to the ignitor. The Trailing (yellow and green) has an L on it? Does this mean that it's wired up incorrectly and the wiring diagram is also wrong or does this mean my car is "special" :D

Re: Starts on one rotor (sometimes) wont idle....

Posted: Wed Aug 05, 2015 2:55 am
by TOOL
Have you got the leads on the right coils?

Re: Starts on one rotor (sometimes) wont idle....

Posted: Wed Aug 05, 2015 12:32 pm
by codge
wiggman2030 wrote:Right I had a look at a wiring diagram for a 83. I'll just confirm this first :)

So the black and white wire comes from the ignition swtich to the leading and trailing coil as well as two wires to the dizzy ignitor and one to a condenser then earth. Are you saying that I need to disconnect the current black and white wire from the ignition coils and run a flying wire from the battery instead, bypassing the ignition circuit? Would I leave the current wire from the ignition to the ignitors and condensor intact?
Yes, leaving the wiring to the engine side alone would seem to be a good first step to me. You're just then bypassing the fixed loom ignition circuit with a temporary feed. Leave the condenser in circuit.....it seems to be at the coils anyway.

Re: Starts on one rotor (sometimes) wont idle....

Posted: Wed Aug 05, 2015 5:55 pm
by wiggman2030
TOOL wrote:Have you got the leads on the right coils?
I have the Leading lead attached to the coil with the yellow and green wire on it. This corresponds to the ignitor nearest the vacuum advance solenoids. The trailing lead is attached to the coil with the yellow and blue wire. This is connected to the ignitor with the same colours nearest the front of the engine (opposite the solenoids). Although the wiring diagram shows this to be the wrong. Does that sound right?

Re: Starts on one rotor (sometimes) wont idle....

Posted: Wed Aug 05, 2015 5:57 pm
by wiggman2030
Ok thanks codge. i'll try that as soon as I get it back together. I think the condenser is that thing under the distributer where that lonely wire goes haha. I'll let you know how I get on :D

Re: Starts on one rotor (sometimes) wont idle....

Posted: Wed Aug 12, 2015 8:20 pm
by wiggman2030
Right ok, after lots of faffing about. I've diagnosed it as the carb that's at fault. I recently had it apart again to make sure that everything was clear and clean (which it was). The only problem now is that it won't inject fuel when I press the throttle and it doesn't seem to be letting any fuel in. I'm pretty sure it's my fault. The upper part of the carb has a split in the gasket when I took it off the first time. I tried to put some gasket sealer on it which worked (to some degree) hence the running on one rotor and not idling properly. Now the second time I created a second split and again sealed it up but now. Nothing, no fuel at all (apart from what is in the floats). After lots of winding and no fuel I just poured a little fuel down both ports and boom, straight into life with the first flick. It ran on both rotors for a couple of seconds unlike the other times i've tried.

So I'm going for a carb... again haha. This time i wont mess with it.... much....... :?

Does this sound like the right course of action?

Re: Starts on one rotor (sometimes) wont idle....

Posted: Wed Sep 02, 2015 10:36 pm
by Casey
I share your pain! I've just had a very similar problem when trying to tune KIMI2 today. The previous owner said someone had tried to tune the carb when he had it, and made a complete mess of it, so he said it needed sorting. I have run the engine up to temp a couple a times previously without any issue and was hoping to drive the car for the first time today (after a tune-up) to test new clutch and brake caliper refurb, but it didn't go to plan..... :(

I got the engine warm, then set the idle to ~1300rpm and slowly screwed in the mixture screw until the engine started to hunt, then backed off the mixture screw to get a steady (but high) idle. I then slowly screwed in the idle screw to get to around 800-900rpm, Did that, and all seemed OK, but after about 30-40 secs on idle she got very rough and the engine stalled. Restarted the engine and she ran on just the front rotor. Thinking it must be something to do with the mix/idle adjustments, I set the idle high again and backed off the mixture screw a turn. Still one rotor. Eventually managed to get the 2nd rotor to fire by cycling the throttle between 1500 and 3500 rpm. Engine seemed OK again. Set the idle back to 1000 and all seemed fine for about 30-40 secs and then she ran increasingly "lumpy" but I managed to keep her running by blipping the throttle. She then started to run on just the front rotor again!

Cleaned the dizzy contacts and dizzy housing, checked all HT contacts (all bright, clean and tight), checked for sparks (OK), changed over HT leads, no better. Took out plugs several times to find the front pair were dry and reasonable colour, rear pair wet.

Before I found this thread I was suspecting a carb or vacuum issue? I have a spare carb and rebuild kit, so am thinking of stripping that to clean it up and rebuild to swap. However, I'll also print out this thread and will do the other checks recommended first.

If there are any other suggestions then they will be gratefully received. I really want to get her up and running on the road asap, as I think I just need a new windscreen (now in hand) and she'll be ready for an MOT.