[loco]

hi all,
i could use a little help.

car quit running.

i put on a coil, wires, cap, rotor, points, condenser and plugs.

spark is so weak engine barely runs. misfires so bad and only smooths out at 0 dwell.

i am at wits end.

12 volts at pos coil terminal and 9.6 at negative side

it's not the carb

sorry to beg for help but i am out of ideas.

will an hei ignition solve my problems?

did i jump time? compression is good on all 8.

resistance wire messing with me?

i haven't seen my family all week!

thanks for any help.

[mrrat1]

Check the rockers, when my cam wore out car ran like crap, push rods came off some rockers. Might be worth to check out if motor has miles on it. Dave K.

[Doug Christie]

Try another condencer.

[68lemans462]

have the module checked.

[george kujanski]

If it jumped timing you will see that with a timing light. If you need to readjust the distributor substantially, it may have jumped, altho retiming it should improve it. Won't fix the prob but at least the ignition timing will be correct.

"smooths out at 0 dwell" how can that be? Can't be zero dwell. Set your point gap to spec and set timing. As stated above, replace the condenser (capacitor) to see if it is the prob.

Got the coil wired correctly? The (-) side needs to go to the points.

Got a vac hose that fell off/leaking?

George

[6969bird]

someone correct me if i'm wrong, but i don't think you should have 9.6 volts at the negative side of the coil. all of the voltage should be used up in the coil windings, correct? on that assumption, it seems to me that the coil is bad and is not building the necessary secondary voltage to fire the plugs effectively. as i said, someone is welcome to correct me if i'm wrong about something here

[george kujanski]

As the points open, the voltage on the (-) terminal (as measured by a multimeter) goes to battery voltage, and when the points close the voltage goes to zero. What you end up measuring is an average voltage.

Using a multimeter on the (-) side of the coil when running doesn't really tell you much.

George

[runningbwdog]

Hi,
Try this simple test. Connect a jumper wire from the +terminal of the battery to the +terminal of the coil. Start the engine. If it runs okay, then you have a bad ballast resistor (wire). You may also have a bad contact in your ignition switch.
Hope this helps.
Mike

[chiphead]

With key "on" and engine stopped and points closed, you should see 6 volts to 8 volts at the (+) side of the coil. This is if its an external-resistor coil. If internal resistor coil, you should see battery voltage. You should see less than 1 volt at the negative (-) side of the coil with points closed. With points open, you should see battery voltage at (+) side of coil and about the same at (-) side, since circuit is now open at points.

You can also close points, and open them manually with a screwdriver to check spark. Sometimes coil output is weak during cranking. Opening points with screwdriver lets the ign system throw a spark without the starter hoggin all the juice. Sometimes timing changes after installing new points, so base timing must be re-set when work is done so engine will run right.

Let us know what voltage readings you get, and we can go from there.

[screamingchief]

I can tell you it did'nt jump timing if the compression checked out OK,if it did jump timing compression would be virtually non-existant.

So its not that.

From what you've described I would look into your wiring to the coil as suggested previously,you should only "see" 12+ volts at the coil when cranking the engine over,this is to help it start quicker,otherwise the voltage should be less due to the resistance in the coil's wiring to keep from damaging the coil.

Also look for the obvious,like is the breaker plate grounded to the distributor housing?

Often the lead for this will fail after many years of use,and can be a cause of "mystery" issues.

Have you checked the wiring to/from the starter?

If you hook up the starting voltage lead to the coil to the wrong terminal on the solenoid it might explain a constant 12+ volts to the coil situation.

[mrrat1]

Originally Posted by mrrat1

Check the rockers, when my cam wore out car ran like crap, push rods came off some rockers. Might be worth to check out if motor has miles on it. Dave K.

Sorry misread your post Dave K.

[loco]

thanks for all the advice

to doug - new condenser is the next thing i'll try. maybe i bought a bad one

to 68lemans462-what module and how do i check it?

to george k-timing is on but it misfires and is jumpy. when i set dwell to 30 car will not run. the lower the dwell the "better" it runs. i think with cotacts closed for so long the voltage builds up enough in the coil that it is enough spark to fire the mix. coil wired correctly, no leaks.

i goofed on the voltage data. i have 12.xxx to coil when cranking and 9.xxx in run/on.

to runningbwdog-we did the simple test, no change. ill check ign sw tomorrow.

to chiphead-i'll post voltages

to screamingchief-i agree about the compression. i'll check the breaker plate. all wiring is new. i'll check starter wiring tomorrow.

once again, thanks

[johnta1]

Dwell should be set first, then the distributor timed.
The distributor is probably too retarded right now, and lowering the dwell advances the timing enough to fire.

Advance the distributor a tiny bit, set the dwell, then recheck the timing with the vacuum advance disconnected.

See what that does.

Also there is no module in a point setup.

[Doug Christie]

From loco's other post on this problem and what I based my advice on.

"hi from a newbie,

yesterday i was driving and had to turn around so i stopped, hit reverse, and when i grabbed first again the car started missing and bucking so bad i had to have it towed home.

here's what i know:

2 hours and about 20 miles before trouble started i checked inspected plugs and gaps-good
i put ten gals of 93 in
it had not so much as hiccupped lately
fuel pump working-don't know pressure
it's got a holley 650
it starts well but idles rough
both float chambers getting fuel
the accelerator pumps are porting fuel properly but when actuated the engine starts to die----too much fuel?

fuel filter not clogged
vacuum lines intact
NO backfiring
it's a 66 lemans WP block, which leads me to my other question. did any WP blocks have 4 barrel intakes? or were they all with 2GC'S.

today i'm gonna check timing and pull the rotor and inspect and check points and i want to troubleshoot as thoroughly as i can before i swap carbs out of sheer frustration. it was on my list but not this soon.

thanks for your time, patience and especially your help.

joe"

[loco]

that's what i figured doug. i swapped carbs with a known good one and no change.

thanks,
joe

[Geoff]

Changing dwell changes the ignition timing. Going from large dwell to a smaller dwell advances the timing, which you say makes it run well. The problem sounds like the initial timing is much too retarded. Set the dwell mechanically by adjusting the points gap to 0.016" - 0.017". This will get the dwell in the ball park. Now adjust the initial timing, making sure the vacuum advance is disconnected & plugged while doing this. Initial should be in the range of 4 to 12 degrees BTDC. I would use 10 to get the timing set up. Once you have it set at 10 BTDC, you can go back & fine-adjust the dwell. Then, recheck the initial timng, because it will change if you altered the dwell.

[Region Warrior]

[QUOTE=Doug Christie]From loco's other post on this problem and what I based my advice on.

"hi from a newbie,

yesterday i was driving and had to turn around so i stopped, hit reverse, and when i grabbed first again the car started missing and bucking so bad i had to have it towed home.

How quickly and at what rpm did you do this?

[slowgto]

loco,

How did this come about? Was the car running fine and then quit? Did you change anything before it started running bad?