Technical ignition issue

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Technical ignition issue

reneb

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I removed my distributor including the shaft from my 500 with a 110.004 engine recently.
The car ran fine before removal although the timing looked to be off when checking with a strobe timing light, but again the car ran fine.
The distributor has an electronic ignition unit installed

After re installing the distributor following a standard procedure of first cylinder at TDC etc., The car only runs on one cylinder (second)
I checked for sparks at the sparkplug for the first cylinder which is has. New sparkplugs made no difference, the cylinder got good compression and all else seems ok.
Timing is now reading correctly with a strobe timing light.

WHAT AM I MISSING?
 
Thanks, The cables are connected and inserted correctly resulting at plugs that produce sparks upon testing. Is there a possibility in setting the timing such that it will only run on one cylinder? Currently what is indicated as number 2 on the distributor cap feeds cylinder 1. Reversing the wiring results in a car which does not start at al.

How can an engine run and start easily on one cylinder while the other cylinder gets compression, spark and I assume fuel by the smell of it, too.

Totally confused by this.
 
If the engine is persisting on only running on 1 cylinder, it could be that the 'non-running' spark plug has, because it is not firing, got 'wet'---try taking both plugs out, cleaning them, checking the electrode gap, DISCONNECT THE 'KING-LEAD' and cranking the engine with you foot fully down on the throttle (with the plugs still out). this will blow any surplus fuel out. Then, with the plugs nice and dry and correctly gapped, refit them, reconnect the 'king-lead' and try starting the engine again.
banghead.gif
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I removed my distributor including the shaft from my 500 with a 110.004 engine recently. WHAT AM I MISSING?

Basically I think your engine is now scrap... you need to send it to me.. and I will supply you with a fully rebuilt engine as a replacement at a reasonable cost :)
Not that I am influenced by the fact it's a 110.004 engine in the slightest!!!

If this engine number does not match the alloy chassis plate then clearly the wrong engine for the car and the engine itself has decided that it needs a new home in my garage.

Other than that I have no idea what's wrong... :devil:
 
Basically I think your engine is now scrap... you need to send it to me.. and I will supply you with a fully rebuilt engine as a replacement at a reasonable cost :)

:D:D:D
....or you could remove the spark-plugs, leave them out overnight, charge the battery and then fit new plugs and give it a try. Sometimes plugs will be faulty even though you see a spark when they are removed.
 
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I agree with all the advice from members above and you do seem to have already checked all the usual things.

You say the engine ran OK'ish (presumably on both cylinders?) until you removed the distributor. Now with the distributor refitted the engine only runs on 1 cyl.

Did you do anything else to the car while the distributor was out?

Any chance that something got disturbed/damaged in the distributor while it was out? You didn't say what type of electronic ignition is fitted but maybe the pick-up in the distributor got damaged. I've seen one where one finger of the rotating chopper (Hall Effect pick-up?) was bent and threw off the timing badly on that cylinder.

Check out the plug leads with an ohm-meter if you have one, including waggling them while testing. Otherwise swap both leads over at both ends (plugs and distributor if the leads are long enough).

Sometimes a plug will fire when connected to a plug lead outside the cylinder but will fail to fire when installed and under compression pressure.

Check the inside and outside of the distributor cap for any cracks or tracking marks (looks like a spidery line of carbon on the cap surface).

Try running the engine in the dark and watch for any sparking that shouldn't be there.

You say there is compression on the cylinder that is not firing, but have you got enough compression? Can you measure it and compare with the other cylinder or the figure in the manual? If compression is low, try checking/resetting the valve clearances (valve lash) and re-measure. Low compression can cause a misfire, even lower can result in non-firing on that cylinder.

I've heard it said that new spark plugs will foul with fuel easier than used plugs... I assume the plugs you're using are the correct heat range, although even plugs that are way colder in heat-range should fire for a while before fouling with fuel.

Only other possibility is that a Gremlin has gotten into your engine. Very difficult to find and eradicate Gremlins....:bang:

Al.
 
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Thanks for all your replies. The problem however persist so BigVtwins suggestions must be correct :)

I am however not about to give up: In response to F123C,
The care ran beautiful before I took the distributor out. Both cylinders show 125 PSI compression. I use an accu spark electronic ignition. played around with the plug leads and spark plugs which made no difference.

Plan on taking the accu spark out and installing points to see if that makes a difference. I guess after that I'll take the front bumper of to see if that makes a difference unless any of you has a better suggestions:)
 
I had a problem years ago with a montego, sometimes it would run like a pig,eventually I found that the porcelain part of the plug was cracked and therefore producing missfiring
 
I am still messing with this car and unable to resolve this issues. I replaced the electronic ignition with points, I replaced all wiring, plugs, cap and rotor. Checked the timing once more and it still runs on only the first cylinder.
Same compression in both cylinders (125psi)
Carb was rebuild some time ago and I am finding no issues there.
So I have fuel, compression and spark, but only one cylinder which is happy with what I am doing.
 
It's a bit concerning that in an earlier post you said you "Currently what is indicated as number 2 on the distributor cap feeds cylinder 1. Reversing the wiring results in a car which does not start at all". Are you sure that you haven't put the distributor back in 180° degrees out.

When you line up the timing marks on the flywheel so that they line up with the mark on the crankcase that indicates TDC, what direction is your rotor arm point?

The fact that all you have done is removed the distributor would suggest it's not been put back in correctly. It's easy to mistakenly put it back in 180° out.

Tony
 
That really is a mystery, and although I have learned not to take anything for granted, it looks like we can eliminate all apects of ignition.

Compression may be good, but that doesn't necessarily mean that all is well in that regard. It is still possible that the valve clearances on the number 2 cylinder are too wide, perhaps resulting in poor induction of fuel/air and/or insufficient exhaust. I had this situation in an instant when one of the nuts holding down the rocker-shaft came loose.

I think it's worth taking off the rocker cover to look for problems of that variety.
 
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That really is a mystery, and although I have learned not to take anything for granted, it looks like we can eliminate all apects of ignition.

Compression may be good, but that doesn't necessarily mean that all is well in that regard. It is still possible that the valve clearances on the number 2 cylinder are too wide, perhaps resulting in poor induction of fuel/air and/or insufficient exhaust. I had this situation in an instant when one of the nuts holding down the rocker-shaft came loose.

I think it's worth taking off the rocker cover to look for problems of that variety.

You beat me to it sounds more like a valve timing issue to me. you could have one valve completely closed and still get compression. could be related to the distributor being 180 out. Need to go back to basics and ensure TDC, timing marks and valve operation are all correct.

Robert G8RPI.
 
That really is a mystery, and although I have learned not to take anything for granted, it looks like we can eliminate all apects of ignition.

Well I'll challenge you!!!:D Because I have decided to become your forum troll!

How can you eliminate all aspects of the ignition, if reneb says it only runs on one cylinder with the HT leads swapped around? I understand your alternative theory. In reality if all someone has done is taken the distributor out, the most likely cause of the problem is going to be distributor related. It would be extremely unlucky to suddenly get a valve issue at the same time.

In my experience of fault finding you always look for the obvious first, what has changed recently and what was happening at the time that could have caused it?

Troll Tony:devil:
 
My understanding of the orientation of the distributor is that it doesn't actually matter if you get it 180 degrees out as long as you switch the plug leads too.
In fact, the numbering on the 126 distributor cap and presumably the orientation of the rotor-arm at TDC are opposite to that on the 500.
Incidentally, I think you can be a bit out on the tooth alignment of the distributor and still get the engine to fire as there is a lot of leeway in the fine adjustment available.
It is probably wise to avoid either of these scenarios but if the engine fires enthusiatically and actually "runs" on one cylinder, you are pretty good on timing already.(y)
 
Well I'll challenge you!!!:D Because I have decided to become your forum troll!

"The Trolls are small creatures who live in an almost perpetual state of happiness, singing, dancing and hugging all day long"

How true Tony:)

Good point made though; I read back to the bit where reneb says swapping over the leads results in no starting at all so you (may be :D) right.:rolleyes:
But swapping the leads would do that because both cylinders would be firing at the wrong time.

But if everything ignition related has been changed, you end up chasing your tail even more by not widening the search for the cause of the problem:bang:
 
But if everything ignition related has been changed, you end up chasing your tail even more by not widening the search for the cause of the problem:bang:

Yes but then you are at risk of going off on a complete tangent. When the only obvious change has been the distributor has being removed.

If it was me I would go back to basics. Line all the timing up manually on the flywheel, making sure you have the rotor arm pointing to number one on the distributor cap, making sure you have the HT leads on the right cylinder etc... I am not sure if this has been done, as previously it has been mention that the HT leads were plugged into the wrong cylinders?
 
If it was me I would go back to basics. Line all the timing up manually on the flywheel, making sure you have the rotor arm pointing to number one on the distributor cap, making sure you have the HT leads on the right cylinder etc... I am not sure if this has been done, as previously it has been mention that the HT leads were plugged into the wrong cylinders?

I think reneb should do that but I fear his response might be "I already have done." As quoted:

"I am still messing with this car and unable to resolve this issues. I replaced the electronic ignition with points, I replaced all wiring, plugs, cap and rotor. Checked the timing once more and it still runs on only the first cylinder."

He seems to know what he's doing and has done it thoroughly. It sounds like he's hoping for a bit of lateral thinking to help out. I reckon the car needs a vigorous tow-start and if that fails he can carry on to Bigvtwin996 's home for retired Fiat Automobilia.:D:D
 
don't want the whole car... just the engine.....
Well ok the gearbox/starter too as well as the new engine will be a 3 bolt starter

I would say that it's a sign from above that it is destined to be replaced with one of those more modern units 110F or similar....
must be past it's best before date......
 
This reminds me of an interesting chat with my local buddy on the weekend about my distributor.

He said effectively: "before you ever unbolt the distributor from the engine, make 100% sure you check the precise alignment of the rotor. When you put it back in, the rotor needs to be pointing exactly the same way otherwise you will pull your hair out with a car that won't start"
 
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