No spark

[TylerJkramer]

I have a 1976 dodge american clipper RV, i just finished rebuilding the engine and when I went to start it for the first time i had no spark. I checked the coil and its good, sparks when I break ground. Everything worked ignition wise when I first pulled the engine. I have bypassed the ballast resistor just in case and have 9v at the + side of the coil, but even when I jump the coil I still get no spark. I have attached photos of how I have the distributor wired up, i tried to wire it the same as before using photos I took. I have a fresh ignition control module just incase that was the issue and have tested that its properly grounded. All engine grounds are good. Ive spent the past 4 hours outside in the heat trying to fix this and am about to light the thing on fire and call it a loss. Please help, I have to move out and move into the RV in 3 days and it probably should be running

P.S
I know the wires arent fully attached at the coil but that becasue im not sure if theyre right, theyve always been tight when testing.

 

[doug 371]

Make sure any engine ground straps are in place and tight

 

[TylerJkramer]

Make sure any engine ground straps are in place and tight

Thank you! First thing I checked, all engine grounds are tight, sanded and brushed

 

[doug 371]

That plug to the distributor looks not quite all the way in?

 

[doug 371]

I think the ballast resistor is jumped wrong. They join length wise not top to bottom

 

[TylerJkramer]

I think the ballast resistor is jumped wrong. They join length wise not top to bottom

Just changed that, still nothing

 

[TylerJkramer]

Took photos on disassembly but they never show what you need. I’m just trying for first start here and thinking insurance fraud might be the way to go

 

[Bewy]

Basics, basics, basics:
- disconnect p/up & measure resistance. Should be 150-600 ohms. Wiggle the wires while measuring to make there are not broken.
- check air gap, should be 0.008". If the reluctor tooth touches the p/up, no spark. If ok...
- run a wire direct from coil [+] terminal to bat [+] & see if it sparks.

These are simple, not invasive tests that 5 min. There are many things that can cause ign failure. The wiring around the bulkhead connector looks like a real bids nest...

 

[halifaxhops]

Also that ECU is suspect it is new but a China version.

 

[Kendog 170]

Try the old ECU.
Not sure if this schematic will help reviewing your wiring. I also copied this a while back from @67Dart273 a while back.

Ignition tests and tester



Sorry I have no idea what you mean by "ground wire." There is no ground wire in a factory or aftermarket Mopar ignition system. The module is grounded at the case and MUST be so

Some things......

Hook it all up, clip your meter to the coil + and ground and turn the key to "run." Should be somewhere between 5-10v or so. this shows that the current is going from the ignition switch through the ballast through the coil, and to ground through the module.

Twist the key to start and read the meter. Should be bare minimum of 10.5V or more.

Connect the meter to coil NEG and to ground and with key in "run" you should not read more than 1-2V or so. This again shows current is going through coil and that the module is grounded

If there is any question, and I would check, about the module ground, remove it, scrape around the mounting holes on the module and firewall, and re-mount using start lock washers

Remove dist connect, and module connector, and inspect them for corrosion. Work them in/ out to scrub the terminals and "feel" for connector tightness.

Next "rig" a test gap such as old plug opened up, with (if possible) a solid wire from coil tower to test gap. Turn key to "run." Separate the distributor connector and tap the bare end of the engine bay side of the connector repeatedly to ground. Each tap should produce 1 nice blue "snap" spark.

Inspect inside the distributor, for wet, dirt, junk, in the cap, inspect the rotor for spark "punch through" to the shaft, and inspect the pickup and reluctor for strike damage, debri or other damage. Estimate bearing play. If possible check the rotor gap with a brass feeler gauge. You once could buy those singly from Oh'Really?s I believe .008" that is inches not metric.

Hook your meter on low AC that is right AC volts to the dist. connector and crank the engine or spin the shaft. Pickup should generate about 1V AC

67Dart273

Well-Known Member​

Joined

Oct 14, 2010​

 

[RustyRatRod]

I just thought I'd beat the regulars to it.

 

[67Dart273]

Reconnect EVERYTHING as per normal and run some tests.

1.. With key in the "run" position, measure at either of the two connectors on the ballast which are jumpered, blue in the diagram, other probe to ground. These should be close to battery voltage

2..Measure from coil + to ground. This should be some lower, perhaps 6-10V. If it is "same as battery," the coil is not drawing current, or the box is not grounded, or not getting current.

3....Measure from box mounting flange, stab HARD to ground. Should be zero, no voltage

4..Measure from coil NEG to ground. should be very low perhaps 1 or 2V. This shows that the box is grounded, getting power, and that the coil is drawing current.

5...Now "rig" a metal core wire (NOT a radio suppressor coil wire) to a test gap or old plug. You can use low voltage wire if you "hang" it away from metal

Separate the distributor connector. Take the harness end, NOT the distributor end, and tap the bare terminal to ground. Each tap should give you one hot blue "snap" spark at least 3/8" and typically 1/2" long

Inspect the distributor connector for corrosion with a flashlight. "Work" it in out several times to scrub corrosion off the terminals.

Try to crank USING THE KEY and look for spark. Clip your meter to the coil + and crank USING THE KEY and read the meter while cranking. Voltage should be at least 10V or more

Make CERTAIN ECU box is grounded. Remove, scraper around bolt holes and re-mount using star lock washers.

Remove ECU box connector work it in / out as well and reconnect.

If you can round up a .17 caliber rifle cleaning brush (same as a bb gun) they usually fit those female cavity terminals.

Inspect the distributor shaft for play in bearings, wobble, and for debri and rust between the reluctor and pickup, and for damage to the two. You can put your meter on low AC that's right AC volts and connect to the dist pickup. Crank the engine, it should generate about 1V AC