Hi Everyone.

Im working on my fathers old 79 supercab xlt, it’s been sitting quit some time. It has a 400 in it.

I have put a new solenoid, starter, and coil on it. I have verified TDC while pointing at #1 on distributor, I even redid the plug wires to check if it was 180 and when I did it backfired through the carb. It’s got a freshly rebuilt carb with good gas and squirts when pumping. I changed the plugs in it and have verified spark to the plugs with an inline spark tester.

I’m scratching my head on this one. I’m not sure what to check. It acts like it wants to start if you spray some starting fluid down the carb.

Any help will be greatly appreciated.

 

put a splash of gas in it and put the lid back on. if it wants to run it's fuel related .

 

Take the fuel tank and old fuel out of the start sequence, no sense in junking up a freshly rebuilt carb right?

Get a 2.5 or 5 gal gas can set it by the front tire, rubber line from gas can, (full of gas and line IN the bottom of the gas can) hook it to the IN port on the mech fuel pump. Take the OUT line (to the carb) off the fuel pump. Spin it over, it should squirt fuel OUT the OUT port of the mech fuel pump after 1, 2, 3, 4 revolutions. No fuel come out I bet bad mech fuel pump.

Replace mech fuel pump, I mean you have replace all the other elec stuff. Except for the Ignition module. In the inside dvrs side inner fenderwell. Get to to run off that gas can.

Other trouble shooting tips: (FMC) Try this test: Connect a test light from the TACH side of the coil (negative side) and ground it on the engine block. Use the key to crank the engine, and the light should blink.

(FMC) Do you have a multimeter? Next you need to check the resistance of the pickup in the distributor. Unplug the distributor and measure the resistance between the orange and purple wires - use the side of the plug that is coming off the distributor, not the side that comes from the harness.

(FTE member) "So I went to test the orange and purple wires and decided to follow the wires all the way to the pickup, well after removing the distributor cap I looked at the orange wire, it was not even attached to the magnetic pickup, so next question? I see that there is a small metal clip and a grounding screw inside the distributor, but I did not figure out how to remove the magnetic pickup so that I can replace it.

(FMC) The veined armature has to come off of the distributor shaft before the pickup can be removed. The pickup comes as one unit comprising of the baseplate and a pivoting breakerplate (a term leftover from points style ignition) with the actual Hall Effect sensor mounted on the pivoting breaker plate.

(FMC) The armature on the distributor shaft must be removed. This is the 8-legged piece you see when you remove the distributor cap. Once the armature is out of the way, the pickup assembly can be removed with two screws. The distributor stays put the entire time.

(1ton basecamp) Also, one way to test the theory of it being a bad relay/solenoid/or the ignition switch wiring, is to pull the Red w/blue wire (the "S" wire) off of the relay while it's cranking uncontrolled. So the next time it sticks (starter solenoid contacts weld shut) and keeps the starter spinning, pull the small "S" wire. If it stops the starter from spinning, then the problem is before the relay. If the starter continues to crank/spin, then the starter relay is faulty.

 

You might be just off on the initial timing. Check it while cranking.

 

This was the issue with my 78 super cab,, If everything else checks (gas, fuel, spark) out this may be it

My truck would cranks, crank, crank sand then fire right when i let off the key. The voltage to the coil was weak when cranking. Some models have a resistor in the harness reducing the voltage in a run condition. I forget what my exact specs were when OE parts. In my rebuild i tossed all the motor-craft spaghetti and installed a new Pertronix distributor and a flame thrower coil. The original hot wire to the coil now triggers a Bosch relay that gets it power straight from the battery and not though the entire harness and switch.

If you are on the fence of putting a new ignition in the truck I recommend this route. It eliminated a mile of wire and now it is easy to service or troucble shoot in the future.

PM me if you want to talk.
Chris

 

I did an ohms test on the magnetic pickup coil and it’s reading 0, I’ve verified it 3 times. I tried it on two other truck I have (77&76) and both read 615-625. Looks like I will be replacing that.

Thanks for the help so far everyone and any additional input would be appreciated.

 

Is it Duraspark? (Electronic ignition) I have these specs

 

You say that it has been sitting for a long time. It might be worth checking to make sure that some creature didn't plug up the exhaust system with their nest. I've seen this happen on a car one time where the people left it sitting in the garage all winter while they were in Florida. The exhaust system was packed completely full of dog food when they got home and the car wouldn't start.

 

Thanks for the help everyone. I replaced the magnetic coil pickup in the dizzy and finally got it to run.

I appreciate everyone’s help.

 

Good to hear you got her running again and thanks for letting us know what the fix was as Iam sure will help others.
Dave ----