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Discussion Starter #1
A week ago I had almost finished fiddling with the jetting on my 2 litre GTA Rep.
I had it running the very best it has ever done, since it's completion in May.

A couple of months ago I fitted a 123 Distributor (non-programmable type), and after trying several different curves, found the best one for my engine was curve "1".

I spent the day fine tuning the carbs and it was idling beautifully, timing spot-on, several trips round the block to see how it went, and was very pleased.
At dinnertime I went out on business for a couple of hours, came back to put the car in the garage, and it was reluctant to fire up.
Got it running on 3, just enough to get it into the garage.
I thought it must be a fouled plug, so left it until Saturday afternoon.
No such luck.
Wouldn't start at all.
I have a spark, although probably only one in four revolutions gives a bright blue/white spark, others are orange., on all cylinders.
Compressions are nigh on perfect at around 195 hot on all cylinders.
I am running a new Lucas Gold Sports coil, 3 ohm DLB105, which I also run on my other car, and I've used them for years.
It was running ok before on that coil, but I tried another new spare , just to be on the sure side.
I checked out all the plug leads, all good, (new 6 months ago).
The starter motor is a WOSP lightweight one, again new 6 months ago. Cranks great.
I fitted another engine earth, again, belt & braces.
Still won't start.

As I had a spark, I suspected the 123 distributor, and good old Tom @ Classic Alfa sent me another one to try. No good, exactly the same.
Now I'm pretty good with everything except electrics and this has me stumped.
The only other things I haven't substituted are the ignition switch, and the starter motor.
Trouble is, with the ignition switch, I can't get my head around what it can be, as I have a spark (of sorts), at the plugs, but it won't fire !
Similarly with the starter motor, how can that be up the spout as it cranks really well ?
There's a weird phenomenon with the ignition switch though. Probably three out of four times when you crank the car (and it never fires), as you turn the key to the "off" position, the engine "coughs", as if it's trying to fire, even though it hasn't tried whilst cranking a few seconds earlier.

Now I had this same phenomenon about 35 years ago on a rally car, but it's so long ago I can't remember what the fix was !
I seem to remember it was on a 2300 Vauxhall Firenza, and a short in the starter motor sticks in my mind, but I can't be sure.

Any auto electrics experts out there that can help ?

Many many thanks

Steve
 

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just speculating: what do the specs of the 1-2-3 dist. call for in terms of the coil? Maybe the coil is not correct a correct match. Over adjustment of the carbs? maybe it's too lean for starting cold as you would have tuned it hot. what do the plugs look like in terms of deposits? "cough" on releasing the key sounds like a timing issue (ignition and/or cams to crank) Or/And maybe the electrical system has problem with the starter or ignition switch drawing/providing current, causing a voltage drop the to the ignition system. Are you running a hot enough spark plug?
 

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Discussion Starter #3
just speculating: what do the specs of the 1-2-3 dist. call for in terms of the coil? Maybe the coil is not correct a correct match. Over adjustment of the carbs? maybe it's too lean for starting cold as you would have tuned it hot. what do the plugs look like in terms of deposits? "cough" on releasing the key sounds like a timing issue (ignition and/or cams to crank) Or/And maybe the electrical system has problem with the starter or ignition switch drawing/providing current, causing a voltage drop the to the ignition system. Are you running a hot enough spark plug?
Hi, thanks for the reply. The 123 calls for a coil with greater than 1ohm, the Lucas DLB 105 that I'm using is 3 ohm, and new, and the car has run successfully on it for 5 months (and I've just fitted another new one that I had spare, with no difference). Carbs are adjusted perfectly (I buy, rebuild and sell carbs for part of my living). Plugs are the perfect colour. Plugs are NGK B7ES, and in truth could go one hotter, but it has run successfully on those, again for the last five months, and it wouldn't cause the engine not to fire at all.
I think you've hit on it with the starter/ ignition switch , trouble is, I don't know how to solve it apart from changing them, other than having them tested.
I have a new ignition switch on the way on a sale or return basis, and if it's not the culprit, then I can't see anything else but the starter, and the ignition wiring is a mystery to me.
Steve
 

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to elaborate on last post, when the key is on "start", the starter and switch draw so much current that that ignition system doesn't get enough current to properly spark (or mis-wiring), when you release the key to run, the switch now provides proper current to the ignition system and the car fires on the decreasing residual motion left in the crankshaft but not enough rpms to get it going
 

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Discussion Starter #6
to elaborate on last post, when the key is on "start", the starter and switch draw so much current that that ignition system doesn't get enough current to properly spark (or mis-wiring), when you release the key to run, the switch now provides proper current to the ignition system and the car fires on the decreasing residual motion left in the crankshaft but not enough rpms to get it going
That sounds exactly like what could be happening, all I need now is an idiots guide / diagram to show me how to wire a relay in !

Steve
 

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You can check these things with jumper wires. Remove the wire at the +ve side of the coil and run a 14 gauge or bigger wire it to a good 12 volts source. If you have a spare battery you could use that then you would know for sure that the starter is not loading it. Now try to start the car. If you have good sparks then you have a problem in the ignition switch circuit.

If it still does not produce good sparks then the coil and distributor cap/rotor are suspect. If you run a plug wire directly to the coil and check for sparks you will be bypassing the distributor and that should pin point the source of the problem.
 

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I have been taunted with "The reason you drink warm beer is you have a Lucas refrigerator"
 

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Discussion Starter #12
Thanks Rogerspeed, Kredden, and Alfaparticle for your help. I have a relay on order , the new ignition switch has arrived, and I will try them on Monday and report back. Even if the ign switch does the trick, I'll fit a starter relay,
Steve
 

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Discussion Starter #13
Tried a new ignition switch, no difference, so I ordered a starter motor, fitted it yesterday and EUREKA ! started first kick.
I always thought that the supposed "new" WOSP gear reduction starter didn't crank as fast as it should, and I've replaced it with a Classic Alfa , Alfa 75 type, which has a more conventional look, but weighs about the same.
This new one cranks twice as fast.
Have no idea what's going on inside the WOSP starter, but the car runs better, idles smoother etc.

Many thanks for all your suggestions,

Steve
 
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