I have had an electrical problem that has been worsening over the last few months. I found the best friendly and technical responses from this site so I’ve come to you guys. I own a 1987 d150 with a 5.2 v8 and what started out as a misfire has become a, “won’t start.” Over the last month I’ve installed plugs, wires, voltage regulator, coil, alternator, a new pick up coil in the distributor (gapped at 8), the actual coil before the distributor, a battery, in line fuses (just after the battery) and I’m not sure what else. I have spare parts from another working truck that I had substituted before I decided to install new stuff and still the problem has beaten me. There isn’t a vacuum line on the distributor, no balist resistor, no electronic ignition…..there are two small metal boxes on the driver front fender (relays?) and I’m not sure if they’re the problem or not….I only have one that’s a spare. There is power to the coil. Around twelve volts on the positive side and a small drop to the negative….its only a week old and I have two others and they are’nt giving spark either. I haven’t found corroded harness connections either. The little black box under the driver side fender is the only item I haven’t replaced that I can think of. I have the Haynes manual in front of me and I’m still not seeing it. It completely quit today after I put the rebuilt distributor, plugs, wires, cap and rotor on. Any ideas?
interesting...all new stuff with power at the coil and no spark
- Thread starter 87RAM
- Start date
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pishta
I know I'm right....
drag the negative coil wire over a ground with power to the coil, lay the spark plug wire close to ground, does it spark? Thats coil test. Is the ignition box grounded itself? That is what the box pulls the ground to. Its just a high speed ground switch that is triggered by the reluctor passing the pickup. Pick up a points distributor and hot wire it (coil power to 12V battery and screwdriver across the starter relay..IN PARK) That would discount any mechanical issues like compression or fuel. Again...
Try disconnecting the center coil wire from the distributor and holding it close to ground, crank the engine over and look for spark jumping to the ground.
Also see if a spark will jump from the center wire to the ground when you turn the ignition off...
Also see if a spark will jump from the center wire to the ground when you turn the ignition off...
rednesss
Well-Known Member
Install rotor. 
CrazyCheesehead
Member
Are you sure you installed the distributor correctly? I have done the oops I installed it 180 degrees. It doesn't take much. Also make sure your plugs are gaped correctly, I just ran into that on my tahoe.
Get real,whats key on voltage,to the positive side of the coil? What's running
voltage at the battery,and the alternator? Jus'sayin....
,
voltage at the battery,and the alternator? Jus'sayin....
,
I had a more experienced friend come and check my work. We found the TDC of compression stroke, checked the new rotor position and it was on #1 wire, the gap hasn't moved on the pick-up coil, all wires were installed correctly and everything is aligned and installed as it should be. We turned it over with a spare plug and wire directly from the coil to the exhaust manifold and it didn't spark during revolution or shutdown (key to off). We tested it until my battery started to weaken so that's on charge now. I didn't want to post voltage reading until my charge was above 6 volts. Im going to swap the original battery back to continue testing.
So I found another start run relay and swapped it and the ignition relay without any difference found. I also looked around under the steering column and didn't find any difference there. Also, I removed the alternator from the equation and voltage regulator. Remember I posted that this 1987 D150 doesn't have an electronic ignition or a ballast resistor. I decided to retest the coil and it has good continuity between the posts. Without coil connected, I turned the key to the run (not start position) and found there was power to both positive and negative wires that attach. Both the negative wire and positive wire read 11.8 DC volts.
pishta
I know I'm right....
So it has points? I read that the distributor has a "new pick up gapped at .08" and it DOESNT have electronic ignition? Bingo, you got the wrong distributor! Did I read that correctly? The electronic distributor cannot fire the coil without the ECU (thats a Pertronix modification feature) . If you got a points distributor, just put a 12V test lamp across power and the disconnected coil - lead. The test lamp will pulse on with the points closing to ground. The coil fires when the distributor pulls the negative connection OFF the coil negative terminal. here is a pretty good POINTS style diagnostic aid ripped from a jeep site:
STOP with the GUESSING and throwing parts at it!
Do some diagnostic work...
FIRST OFF,
Get yourself a $6 test light
(or make one with soldering iron and 12 volt dash light bulb).
Get the kind that has a BULB, not LEDs to tell you what's going on.
Connect the 'Alligator Clip' connection of the test light to the battery NEGATIVE.
Probe the battery POSITIVE to see what a 'Bright' light looks like,
And to confirm the test light is working.
Now, disconnect the coil connector from the ignition coil.
Turn the ignition switch to 'RUN' position.
Probe the POSITIVE wire terminal You should get a 'Dim' light,
(Ignition current moving through ignition resistor wire)
Then have someone crank the engine like you are trying to start it,
And observe the test light,
It should be BRIGHT while cranking, DIM while key is in the 'RUN' position.
If you have ANYTHING other than this, your problem is probably in wiring BEFORE the ignition,
Fuse, Switch, Tach, Wiring, ect.
--------------------------------------------------------
SECOND,
Switch the 'Alligator Clip' on the test light to the BATTERY POSITIVE terminal.
Probe the NEGATIVE terminal to see a 'Bright' light and test your connection.
Now,
Probe the Ignition Coil Connection NEGATIVE terminal.
When you have someone CRANK the engine, you should see the light 'FLASH' during cranking, you have a problem...
If you don't have the 'FLASH', that means there is a problem with the MODULE, DISTRIBUTOR, Or The ENGINE WIRING HARNESS BETWEEN THOSE COMPONENTS.
--------------------------------------
STOP with the GUESSING and throwing parts at it!
Do some diagnostic work...
FIRST OFF,
Get yourself a $6 test light
(or make one with soldering iron and 12 volt dash light bulb).
Get the kind that has a BULB, not LEDs to tell you what's going on.
Connect the 'Alligator Clip' connection of the test light to the battery NEGATIVE.
Probe the battery POSITIVE to see what a 'Bright' light looks like,
And to confirm the test light is working.
Now, disconnect the coil connector from the ignition coil.
Turn the ignition switch to 'RUN' position.
Probe the POSITIVE wire terminal You should get a 'Dim' light,
(Ignition current moving through ignition resistor wire)
Then have someone crank the engine like you are trying to start it,
And observe the test light,
It should be BRIGHT while cranking, DIM while key is in the 'RUN' position.
If you have ANYTHING other than this, your problem is probably in wiring BEFORE the ignition,
Fuse, Switch, Tach, Wiring, ect.
--------------------------------------------------------
SECOND,
Switch the 'Alligator Clip' on the test light to the BATTERY POSITIVE terminal.
Probe the NEGATIVE terminal to see a 'Bright' light and test your connection.
Now,
Probe the Ignition Coil Connection NEGATIVE terminal.
When you have someone CRANK the engine, you should see the light 'FLASH' during cranking, you have a problem...
If you don't have the 'FLASH', that means there is a problem with the MODULE, DISTRIBUTOR, Or The ENGINE WIRING HARNESS BETWEEN THOSE COMPONENTS.
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Fantastic feedback...I will do everything and give you an update...thank you very much
SwingerSteve
Well-Known Member
I just put a new coil on my car,, still no spark to plugs but,,, it does fire a spark from the coil to distributor on "shutdown",,, help please??
Try reading through this thread...
Need help with no spark
Remember, just because it's new, doesn't mean it works... Many companies are shipping junk to our parts stores... We had a brand new electronic ignition wiring harness that turned out to be bad, replaced it with another good one, and it fired right up....
Over the last few days I've pulled the harness out of the engine bay and looked it all over. I put it back without the conduit and tape for visual help. It now has a new starter too, not rebuilt. I replaced the grounding wires from the battery. Now the starter clicks only. The original 87 service manual says the coil should have power to both sides and the distributor has power going to it. The neutral safety switch in the transmission is secured well and after that ???? What's next?
If the starter only clicks, you're not getting enough power to it...
Is the battery fully charged??? Are the wires good??? Are all connections tight???
Is the battery fully charged??? Are the wires good??? Are all connections tight???
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