hey all, need some wisdom....just bought a 78 150, 4wd with 351m and 4 speed. PO had taken it to a mud run, and supposedly knocked something loose with the sending unit. got it home, charged the battery, gas to the carb, bam! fires right up...take it around the block a couple times over the next few days and it dies coming out of the inclined driveway and proceeds to not start. replaced sending unit, PO had replaced fuel pump, pulled the line off the pump and plugged a line into a gas can, fuel pump picks up fuel, but now no ignition! I have replaced the cap, rotor, plugs and ignition control unit. turns over just fine, but it doesn't seem to be getting any spark. I suspect the pickup unit on the stock distributor, what about you masterminds?

 

Read This- https://www.ford-trucks.com/forums/1...-ignition.html

There is a diagnostic sequence to trouble shoot DURASPARK.

Use only MOTORCRAFT parts.

 

My 400 died like that a few weeks ago. Pull the cap and make sure the distributor is turning. Also line up the timing marks and look to see if the rotor is pointing at #1. My rotor did turn but seemed slow, timing marks on TDC and rotor was 1 1/2 cylinders off. Pulled the distributed to rind the roll pin had sheared. Replaced the pin and all is good now.

Jeff

 

thanks guys. replaced the pick up coil today to no avail...stupid question, how do i know/where are the timing marks to know I'm at TDC? still very much an amateur when it comes to timing/distributors. Will replacing the distributor as a whole fix the problem? I see they are pretty cheap, but I have absolutely ZERO experience replacing it...anybody have a tutorial with pictures? thanks in advance


edit: so it turns out I had a little electrical connector that wasn't connected to the positive **** on the ignition coil. fired right up on 7 cylinders, since a plug wire decided to seperate while messing with it

 

If its the stock Dizzy, it may do wonders to replace it with a Motorcraft Refurb, like many of us have done to fix ignition gremlins and for $40, worth every penny to rule out all the suspicious systems a worn out one can cause. They are stupid easy to replace and it gives you a fresh start on timing. Best way for me to confirm TDC is to unplug main coil wire, take out #1 plug, press your thumb over plug hole, have buddy crank over engine when the piston is on the compression stroke it will blow your thumb off the hole, stop there and look down at your harmonic balancer/pulley



You should see some marks, like someone had put a line with a white sharpie or chalk, it should be damn close to lined up with a metal tab protruding from the block, those are your timing marks... and if you take a flashlight to the balancer, you should see little lines marked in degrees of separation... Im gonna stop there, cuz i gotta run, someone else can take the lead on the Dizzy install, or order one and then we can walk ya thru it..... No stress on that install, its easy, you got this...

Just seen you solved your problem ! So never mind and Im glad you gotter fixed...

 

Glad you got it figgured out. Your gonna want to learn about timing and vacuum to effectively work on these old trucks. Google and this fourm will be your friend there. Matter of fact it seems any time I Google anything about these trucks it takes me to FTE. FTE search not so good.

Jeff

 

Steps to check the timing:

You'll want to verify TDC, compression stroke, on #1 cylinder.

Take off the distributor cap. Use either a remote starter switch, a buddy in the cab or a socket on a breaker bar on the snout bolt to rotate the engine. As you face the engine, the engine rotates clockwise. Watch the distributor rotor-it rotates counter clockwise. Number one ignition wire will be at roughly 2 o'clock as you're looking over it.

Pull the passenger side valve cover. Number one cylinder is front passenger side. As you rotate the engine, watch the rockers go up and down. They'll both be closed at TDC.

Pull number one spark plug. Use a TDC tool (or a piece of metal coat hanger) to find the piston at its highest point. There will be 5-10 degrees where it's too close to eyeball it, but you'll be close. The TDC tool is exact.

Look at the harmonic balancer. If all is well, the pointer will be pointing at 0. Success! Sometimes the harmonic balancer can slip, and not read accurately. If so, they need to be replaced.

Get TDC figured out, and we can move on to ignition timing...