Technical 235 electrical

This one has me stumped. I converted my 53 chev 235 inline to 12 volt. It started, ran rough, but it did run for a bit and stalled out. Installed a rebuilt carb - still no luck. Then I installed an Ignitor lobe sensor to replace the condenser & points plus a new coil - wouldn't start at all. Then I installed a new Distributor cap and rotor - still won't start.

This is what I've tested so far;

1. No spark to any of the plugs
2. OHMs check out on the coil
3. Ignitor lobe sensor bench tested fine
4. Ignitor lobe sensor tested in the distributor fine
5. Power to the coil is fine
6. Good 12 volt flow through wire from coil to distributor
7. No 12 volt flow through the distributor to the plug wires, even though;
8. Rotor is making contact with the distributor connections

As I said, I'm totally stumped. I have the feeling I'm missing something basic and am going to be all herp-derp when someone says; "Did you check the ..." Any ideas?

 

When you converted it to 12v, did you add a ballast resistor (or change the coil to one that has a built in ballast resistor)?

You should be able to make it work with points...

The rotor should not touch the contacts on the cap, there is a little gap that the 10,000 volt output from the coil can jump with no problem.

 

I was thinking resistor also, but would
That make it not run?

 

I'd call Pertronix and quiz them on the situation. I ran a ballast resistor and was told to take it out. The reason was lower voltage and poorer performance. The installation instruction did not call for one.
Read the instructions!

 

How did it run immediately before you made the voltage conversion? If it ran well before, why did you replace the carb? Were you having fuel problems prior to electrical changes?

Seems there may be missing info here.

Ray

 

Good flow of 12 v thru wire from coil to distributor? The distributor wire should be connected to negative side of coil. Distributor grounds coil intermittently as it turns, either thru points or electronic pickup.

 

Okay, slow it down a little, for the slow minded people.

1: no spark. That's a problem to handle.
2: ohms fine in coil? To what side? And how much?
3: it's all good, and it's new
4: it's all good, and it's new
5: that's good
6: so you put ignition on and the wire that connect to you new unit, and measured 12 be at the end of that wire, with a multi gauge?
7: the rotor has a build in reatrictor, so people around you can listen to the radio, if you got an exhaust system on.
Did you ohm cables? Are they in the same ballpark? There should be some ohm, iirc it should be between 4-6 k-ohms. And they all should be with in the same k-ohm. But I don't think that's you problem. But it dosent hurt to check.
8: there should be a slight gap.

I would as follows for your next step of diagnostics. Pull al cables/wires of coil, run straight battery plus to terminal 15/+ on coil, put a good spark plug cable in coil terminal 4/big center, and connect it to a spark plug that is firmly grounded/just lying on clean metal. Then you connect a wire to the terminal 1 on the coil and put it on ground too.
Don't touch the spark plug or wire at the same time.
You should get a spark when you lift the grounded cable if you do it's good, if not you need a new coil.
If you got a coil with a balaster, a single test with out the ballast wouldn't hurt.

Did you change the coil?
Coils comes in 12v, 6v or with a ballast on it. A ballasted one is a 6v that gets 6v from the ballaster when driving and gets 12 volts for starting. So it's over powered for extra boost for a short period of time, so it help do a cold start.

I hope this makes sense, and I hope I didn't over complicated it.

Feel free to ask more questions, and return with your result, so other can find help from you trouble.

And remember, if your engine don't starts, simplest and first point for diagnostics is: a squint of something in the intake. If it fires, you got a gas problem, if nothing happens you got a spark issues, if the happens a little but it still doesn't start, you might have a compression issue.
And the rest follows a simple line away from three directions, and ends up with it driving or on the way out!

 

Is it running yet, it might be because of the time difference, but I would like to see some progress.
Just feel free to call me impatient. [emoji4]

 

How about an update. You had people trying to help, then you disappear. Not good.

 

My apologies to all; I thought I had some free time to sort this out, then work called. Just finished setting up a new contract and providing training out on the road. It turns out I FUed the wiring to my ignition switch - it runs now, but flattens out at half-pedal. Vacuum turns the distributor, so I'm thinking it's a fuel pump issue. Going to tackle that next.

 

check your timing first

 

Check fuel pressure. You don't need a ton- 3-5 psi normally. But if it ran fine before you changed electronics, you are probably over complicating.

 

OK... I'm having a little trouble interpreting this one.