Won't start-no fire

[tjvending]

Won't start-no fire. I just change out carbs because I was having smooth running problems with a dirty carb. When I go to start it just keeps turning over and over. I notice the wire was off of the starter from the coil, I fixed it and still no start. I checked the coil and it is good (checked with another truck) I have no fire at the spark plug (holding it against the frame), seems to be getting gas. I thinking may be the points. Can you help me out? 72 C10 with 307, auto.

TJ

[Getter-Done]

Take the cap off and check for fire at the points. Also check the gap of the points. You can Take an (old) penny and run it thru the points.
It may clean them enough for it to start ( if that is the problem).

[rockyrivermark]

Best thing is to just put a HEI dizzy on and be done with the points.
Summit sells them for about $80 and you don't have to keep messing with the points. More reliable and stronger spark

[tjvending]

I have power at the coil and at the points but none coming out of
the coil but coil is good (tested)

[tjvending]

I took of the cap, I see no condenser at all, shuldn' t there be one? Ran before my problem though

TJ

[tjvending]

Is there a certain one for a c10 307? Or which should I go with?

[tjvending]

Originally Posted by rockyrivermark

Best thing is to just put a HEI dizzy on and be done with the points.
Summit sells them for about $80 and you don't have to keep messing with the points. More reliable and stronger spark

Which one should I go with? 307 engine

[Getter-Done]

Originally Posted by tjvending

I have power at the coil and at the points but none coming out of
the coil but coil is good (tested)

Try another coil wire.

[Getter-Done]

If you do change to HEI distributor like rockrivermark suggested.(which is IMO the way to go also) A distributor for big block or small block will work.

[rockyrivermark]

This is the unit I bought. Real easy to install and so far so good 2 years in
Personally I like to eliminate further problems and reliability which some modern components.
I know some guys want their truck 100 % original which is cool, I get it.
If not this is a nice unit.

https://www.summitracing.com/parts/sum-850001-1

[rjs53]

The only thing I've noticed about the summit brand hei is, they don't put dielectric grease between the module and the plate it fastens to. I have 2 of them, never a problem. But I have an mad distributor and the summit so I looked at both to see the difference and that was about it. The grease helps with insulation.
Did you check the old coil to distributor wire, they pull apart some time and then no spark.

[Steeveedee]

The "grease" helps to conduct heat, not to electrically insulate the module. The correct substance has a lot of metal in it for that purpose. It conducts heat better than just air.

[Steeveedee]

Originally Posted by tjvending

Which one should I go with? 307 engine

If you do not actually have a condenser inside the distributor cap, that is likely the problem. The condenser attenuates high voltage and current surges experienced during closing and opening of the points. The points will be ruined in fairly short order if the condenser is missing. Points and condenser don't cost all that much money, and I'd recommend that you replace just those item in order to track down the problem. Known working old parts are fine for this. New distributors and such are nice, but until you actually know what the malfunction is, you might just end up digging yourself into a money pit.

BTW, the points and condenser are the same for all GM V-8s from 1957 until 1973-1974, depending on the vehicle manufacturer. Some went to HEI earlier than others, but the points and condenser fit ANY GM V-8 in those years, unless it has electronic ignition.

[tjvending]

Coil wire checks out OK, not that. I thinking about the condensor not being there.

TJ

[tjvending]

Can I use the combo type, where the condenser is attached to the points?

TJ

[Getter-Done]

IMO I never liked that type.
I guess the people that showed me how to do mechanic work
Would replace them constantly with the type that the condener is separate
Then no more problems. (For quite a while)

[Steeveedee]

Originally Posted by tjvending

Can I use the combo type, where the condenser is attached to the points?

TJ

Those are more expensive than two separate pieces, but yes they will work.

[rockyrivermark]

Originally Posted by Getter-Done

IMO I never liked that type.
I guess the people that showed me how to do mechanic work
Would replace them constantly with the type that the condener is separate
Then no more problems. (For quite a while)

Exactly. Just replace with electronic and be done with it.

[Getter-Done]

It would be good to find the problem because that would drive some one crazy if you put the HEI in and it still won’t start.
Buy the cheap set of points and see if that solves the problem.
Then if you change to HEI remember you need a full 12 volts to the distributor.

[Caddylackn]

It ran before you swapped carbs, so I am assuming that you did not hook all the wires back up correctly.

My first guess is you inadvertently switched the coil + wire with the choke + wire. The choke + wire is 12V but the coil + wire should only be around 7 volts to run the points. There is a resistance in the wire to drop it down to 7 volts. There is also a yellow wire from the starter to the coil which purpose is to get 12V to the coil only while the starter is turning. Running a constant 12V to the points will burn them up quick, which may be what happened.

If that is not the problem, the motor should be grounded to the firewall and/or frame, make sure those connections are clean. Make sure the coil - wire is properly grounded or the coil will not fire. Usually the coil is grounded through the condenser, which is screwed to the coil holder, which is bolted to the manifold which grounds it.

[tjvending]

Got her running today. Points and now a Condenser (PO owner ??). It fire right up.

Thanks for all of the help with the questions.

TJ

[Stocker]

Glad to hear you got it going!

[Getter-Done]

Thanks for feedback on the solution a lot of people don't give the results.
Could help someone in the future.
Glad too hear you are back on the road.