Ok here is my situation.

I have replaced alot of parts with brand new items. I have replaced the battery, solenoid, dist cap, rotory button, spark plug wires, spark plugs, coil, ignition module, put in a edelbrock performer intake, and edelbrock carb.

I put a new fuel hose from the fuel line to the carb with an inline filter that is clear. I can see the fuel inside the filter so I know it is getting gas. I also climbed under the hood and looked in the carb to see if it was spraying fuel and it was. So I know fuel is getting in the carb and to the engine.

I have not tested the spark coming out of the coil or the coil wire to the distributor. It was tested before I put the carb and intake in and the guy thought it was puny. That was from pulling the spark plug and turning the engine over.

The engine was sitting up for a year according to the guy I bought it from. It used to crank up very easy but it got to where it was harder and harder to crank until it just didn't start anymore. I tried to do a carb rebuild but it still didn't run. It tried to run some but it would not idle. When it would kinda run it was very rough. I thought it was the carb which is why I replaced it. Now the only thing I can think of that was not replaced is the ceramic resistor and the electronic stuff below the rotory button. I will test the spark from the coil tomarrow to see if maybe I got a bad new coil or something.

Any ideas from all this I told you that I can check?

 

what truck is this ?

 

1978 F250 2WD C6 tranny 400ci

 

Make sure you're not running a full 12v to the ignition coil.. it will last for a while but will get weaker and weaker, proper is like 8v (I think?), there's a resistor wire between ignition or fuse box (I forget) to the ignition coil power.

its easy to test the coil with a multimeter, I dunno exact readings but it should be in both Haynes and Chilton manuals.

 

You know I have been wondering if its possible the resistor is bad but would it cause it not to crank? I guess if it is completely bad it won't send any power to the coil or like you said cause a very weak spark?




This is the way it currently looks. I know in the pic the coil wire is disconnected but it is hooked up now. In the second pic if you look at the wires going to the coil about like a few inches to the left of the coil you can see where someone decided to splice/solder another wire to it so now I need to figure out if I can eliminate that if its part of the problem. Also the wire harness coming out of the distributor is also connected.

 

I can't tell, is that splice power? If so that might be your problem.

 

 

D7AZ-12250-A .. Resistor Wire-Ignition Switch to Coil (Motorcraft DY-213) ~ Color Coded RED / #16 gauge wire / 49" long.

When replacing the ignition module, it's a good idea to ALSO replace the pickup coil in the dizzy. There's only one type used 1974/79.

D4PZ-12A112-A .. Pickup Coil aka Stator (Motorcraft DU-1-A)

 

Ok thanks everyone. I will look at this and report back whatever I find out.

 

What is this plastic thing called that connects to the terminals on top of the coil?

 

Would you believe an ignition coil connector. Check it out here...
http://info.rockauto.com/Airtex/Detail.html?1P1090.jpg

 

Thanks. I tried to tell the guy at the auto zone but he was trying to say it was the Coil and I said no I know it isn't that.

Heading to my second home. The auto parts store.

 

Do some coil tests to make sure.

It won't be the horseshoe connector but clean the terminals on it.

 

did you check to make sure the battery is in right. that happened to me since the red wire is ground and black is hot, my truck would still turn over but wouldn't crank.

 

This is the coil plug (connector) which is part of the engine gauge feed loom.

It could also be purchased as a separate part (without the wires).

D5AZ-14489-H .. Connector-to Coil

D: Text / Section 144 / Pages 17-18 / Type 21.