Where to begin... I bought this truck (1976 f250, 360 5.9L with c4 auto trans) running for 500$. Drove it home (120 miles away), parked it a few days, noticed a fuel leak, fixed the fuel line, and now it won't start.

I've replaced the battery, starter, and solenoid, mostly because I planned to anyway. It merrily cranks, and if I give it a spurt of gas or hold the accelerator down for a second while cranking, the engine will start and rev, but as soon as you let go of the key from "start/crank" just to "run/on" it dies immediately. If i hold the ignition switch to "start/crank" and keep holding it there while giving it gas, the engine will rev and run otherwise normally but I don't do this for very long out of fear of damaging the starter or flywheel/flexplate.

Since it started and idled and ran before just fine (little hard to cold start but it would start and hold an idle) I'm leaning towards it being a spark/ignition issue, though I'm sure the carb can use an adjustment.

I've contemplated replacing the ignition switch next but I'm looking to you experts for some additional advice or checks to perform.

 

Letting the key go from start to run and it dies sure sounds like a elec issue. And I would suspect a bad ignition switch.

I believe the last diagram is a 78/79.

You can get a new outer part of the switch and then search for the thread that tells you how to pop out the center tumbler from the old switch and install in your new switch.

FTE member says..." You can easily test the starter solenoid and the switch.

First, the switch. You'll need a partner and a multimeter.
-There is a 'hot' (12V +ve) wire that is off (0V) when the key is off and on (12V) when you have the key in the start position. You just need to check if you are indeed consistently getting 12V when the key is in start. So, multimeter with one lead on ground and one lead on the wire from the key. This should be a thin (16GA?) wire coming into the 3rd post on the solenoid. Side note: Essentially a solenoid is simply a relay that uses a low current 'switch' voltage to create an electromagnet that closes a switch inside and completes the high current circuit, making the starter spin. Once you confirm that there is indeed 12V coming from the key when it's in the 'start' position, we've ruled out that the key switch is bad.

Next, the solenoid. Like I said, the solenoid is just a switch that uses low current to complete a high-current circuit (the starter). It can go bad without warning, and it's entirely possible and likely that it's bad. So, to test the solenoid (after you've confirmed you're getting power from the switch to the 3rd terminal on the solenoid) you simply take a jumper cable and clamp one end onto one side of the solenoid (12V in from battery) and touch the other end of the cable to the other post of the solenoid (12V out to starter). The engine should immediately turn over (expect a few sparks, no big deal). MAKE SURE IT IS IN NUTRAL IF IT IS A STANDARD TRANSMISSION.

If the key checks out good, and the solenoid test makes the engine spin over, then the solenoid is bad.

If the key checks out bad, you can verify solenoid operation by taking a small bit of wire and going from the +ve terminal of the battery and touching it to the 3rd terminal on the solenoid (where the key goes in) and it should energize the solenoid and turn over the engine."

 

It's a C6. C4's were not installed with FE engines (360/390 etc).

 

Well, Chilton seems to disagree with that.

See code G- C4
See Vin plate- trans code G

 

Chilton is notoriously flawed.

From what I found on a quick Google search, G means a 3 speed automatic, not necessarily C4 or C6.

 

JSMskater, welcome to the forum. When mine was doing about the same thing.... turned out to be the pick-up coil in the dizzy. Good luck on your project!!

 

 

Great! That should make it easy to fix stuff using it...

Good to know- looks like someone posted a nifty chart- thanks! This should help identifying it for sure.

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Thanks! I will check that too.

 

This is awesome thanks

 

Was curious about the C4 application.... and was gonna chime in, but Rich covered the first few tests you need to do... then I would move onto coil and Dizzy... Love me some FE !

 

I'll reserve my "troubleshooting the stator tests" until you've done the tests recommended by Rich...AKA 77&79F250.

Do you have the DSII system in yer '76?

 

Hard to say, I know it does have a large plug coming off the distributor indicative of the breakerless system - the manual seems to think for 76 its just called a breakerless ignition and doesnt become duraspark II until 77 but as someone said above chilton apparently isnt accurate on some of this. The picture labeled duraspark II in the manual looks identical to my distributor so I'm fairly certain it is.

 

Yeah I have no idea what it has, just going by the vin and what the manual said; but one poster provided an awesome identification chart so I'll crawl under and report back and settle the debate.

Ill run these tests (thanks everyone!) And report back.

Ill get some pics posted as well, and a link with a walkaround video.

 

Welcome to FTE.