Author Topic: Uneven running after switching to El. Ign (and back)  (Read 714 times)

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Offline Lyngeled

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Uneven running after switching to El. Ign (and back)
« on: Thursday,July 25, 2019, 01:06:28 PM »
Hello
I have a quick post now. As in in the topic I switched to electronic ignition and it ran worse. It continued doing that after switching back.

My own suggestion are: something with the ign. leads I have made a bad connections or some other bad connection?

I did not have time for more testings today : )

Any other suggestions?

Offline BDA

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Re: Uneven running after switching to El. Ign (and back)
« Reply #1 on: Thursday,July 25, 2019, 01:24:24 PM »
Hmmm... I wonder if there was a chance that you dislodged or broke an advance spring or otherwise damaged something such as the distributor cap. Is the center carbon electrode working properly? Did you get the distributor cap wet or get anything on it that is conductive? Did you take the dizzy out of the engine? If so, did you set the timing after you put it back together? Could you have bumped some carburetor linkage? Are all the HT leads securely inserted in the cap and securely attached to the plugs? Did you check the wiring changes for the electronic ignition and check that they were properly backed out when you went back to points? Did you dislodge or damage any wires to the dizzy or the coil when you made those changes?

Out of curiosity, what ignition did you try? I have a Pertronix that I like. I recommend them.

Offline Clifton

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Re: Uneven running after switching to El. Ign (and back)
« Reply #2 on: Thursday,July 25, 2019, 01:28:54 PM »
Runs worse everywhere or idle? WOT?

Offline EuropaTC

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Re: Uneven running after switching to El. Ign (and back)
« Reply #3 on: Thursday,July 25, 2019, 01:32:22 PM »
As BDA says, what system did you go for ? That might give a clue if someone else has the same system.

I have Pertronix on mine and it runs pretty much the same although I think it starts up and idles better. However when doing the change over I removed the distributor & re-timed the engine afterwards.

Brian

Offline Lyngeled

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Re: Uneven running after switching to El. Ign (and back)
« Reply #4 on: Thursday,July 25, 2019, 01:33:22 PM »
The idle is worse, and it does not perform as before. I also suspected the rotor, maybe also the connection?

Offline Lyngeled

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Re: Uneven running after switching to El. Ign (and back)
« Reply #5 on: Thursday,July 25, 2019, 01:37:35 PM »
It is a PowerSpark.

Offline Lyngeled

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Re: Uneven running after switching to El. Ign (and back)
« Reply #6 on: Thursday,July 25, 2019, 01:43:22 PM »
I will have to wait 24 hours to test just a little more  :(

Offline EuropaTC

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Re: Uneven running after switching to El. Ign (and back)
« Reply #7 on: Thursday,July 25, 2019, 02:29:57 PM »
It is a PowerSpark.
That should be ok on our engines, similar style to what I have. The only things I can think of are; coil resistance - these things are picky about coil resistances and secondly because it's a major operation have you re-checked the timing ? With luck it should be the same and on my early pertronix I can check static timing, but if you can get it running then a timing light will be better.

I also use copper leads but with resistance caps. I note that Powerspark insist on silicone leads - have you installed the complete package (EI unit/coil/leads) from them ?

Brian

Offline Lyngeled

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Re: Uneven running after switching to El. Ign (and back)
« Reply #8 on: Thursday,July 25, 2019, 07:00:27 PM »
Only the El. unit.

Offline EuropaTC

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Re: Uneven running after switching to El. Ign (and back)
« Reply #9 on: Thursday,July 25, 2019, 09:55:16 PM »
My first check would still be timing although since posting last night I did wonder if there's anything special in the air gap between the switching unit and the plastic magnet unit ?

If the timing and mechanical installation are ok then coil & ignition lead incompatibilities are known issues. If the coil ran ok with points it's unlikely to be the culprit but even so it's worth checking resistance.

Powerspark insist on silicone leads which I've tried but rejected in favour of copper leads with NGK resistor plug caps. (5k resistance). Nothing wrong with silicone leads in principle and they're on modern cars, it was just that I felt the set I bought had flimsy plug caps and overall weren't as robust as copper+NGK caps.

As an aside, there are plenty of tales where the rev counter doesn't work properly with EI units like these. There are fixes, ranging from sourcing the 12v for the EI unit remotely from the rev counter to modifying the rev counter itself.

Brian

Offline Lyngeled

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Re: Uneven running after switching to El. Ign (and back)
« Reply #10 on: Thursday,July 25, 2019, 10:53:09 PM »
I had the distributor all out both times and I tried to adjust the timing. It must be some of the other things.

Offline Clifton

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Re: Uneven running after switching to El. Ign (and back)
« Reply #11 on: Friday,July 26, 2019, 05:13:46 PM »
Solid core wires? Usually bad leaks or wide gap will have a miss under load (WOT) and get worse at peak torque and up. If you had a timing light on it, can you check for full advance? I don't know Lotus specs but I would think it would be all in by 3000 rpm and at least  30 degrees.

Offline Fotog

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Re: Uneven running after switching to El. Ign (and back)
« Reply #12 on: Friday,July 26, 2019, 07:54:59 PM »
I'm still 'getting ready' to drive my car for the first time in 30 years. One of these days I will.   Every so often though I fire it up, like a 16 year-old would do.

One thing I found:  It doesn't run well at all when the fuel is at or below the level of the outlet pipe in the tank.  Even caused me a little panic. 

The key thing for me is that you say "I switched to electronic ignition and it ran worse. It continued doing that after switching back."

I say "Hmmmm!.. must be something else!", if it ran crappy with or without the electronic ignition.  Make sure you're not running out of gas, at least.

For what it's worth, no amount of cleaning and adjusting the points and timing seemed to fix my car.


Offline surfguitar58

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Re: Uneven running after switching to El. Ign (and back)
« Reply #13 on: Saturday,July 27, 2019, 07:04:08 AM »
Solid core wires? Usually bad leaks or wide gap will have a miss under load (WOT) and get worse at peak torque and up. If you had a timing light on it, can you check for full advance? I don't know Lotus specs but I would think it would be all in by 3000 rpm and at least  30 degrees.

Mine was running rough intermittently before the swap to Pertronix distributor, coil, wires and new plugs. In removing the old wires the wire/plug-socket connection came apart in my hand for the #4 wire, so I think an intermittent connection may have been my problem. Clifton is right to ask about what wires you are using. My understanding is special wires (what makes them special? I dunno.) need to be used with Pertronix EI and the “Flamethrower” coil. Car runs terrific now.
Tom
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Offline Lyngeled

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Re: Uneven running after switching to El. Ign (and back)
« Reply #14 on: Saturday,July 27, 2019, 07:26:47 AM »
Hello,
it feels better now, I poured some fuel in and I think it maybe was that. But still I think the idle have been better.

I tried another rotor and cap and chosed the first rotor with a cap that looked new. The other was worn on the contact areas. I wonder why it does not have a spring the make contact. When it wears it seems to just loose contact, too early I think. I will research that more.