Starting trouble-84 F150 351W
 

HELP............
Project truck for my son. We bought the truck a month ago and it had a few problems (intake leak, loose lifter, ran rough, etc). After taking it apart down to the intake manifold and fixing the lifter, we put it back together. As with most older trucks, the wiring was a little jacked up so we had to do some repairs there-anyway, we can not get it to start now. It actually starts, but when the key is rolled back to the run posistion-it quits. We replaced the Key ignition, the ignition module and have verified spark and gas is getting to the spark plugs.
Any ideas?????????

If it is firing while the starter is turning the motor over but doesn't run I would start by making sure you have your plug wires on in the correct order.

Thanks for the response. I thought the same thing, so I checked and re-checked the order and connections.
I have a feeling it's an electrical connection somewhere, I just don't know enough about what wire/connection would be related to it starting and lossing connection when the key is relaxed back to the "run" posistion?
I have verified power getting to the coil, coming out of the coil, power to the dist, spark getting to the #1 plug, fuel getting to the plug-and after that, I am at a loss?
The only thing I have not checked is how many volts are coming into the coild, and how many are coming out-just not sure how to do that?

Here is what I would do. Run a temporary wire from battery positive to the coil positive terminal. If the engine starts and stays running , there is an open wire from the ign switch to the coil. Before I get you too involved , this is what I would try first. Let us know how you make out. ,,,,,hanky

Thanks for the help.

I tried it with the same results. It starts until I relax the key back??????

Here is something for you to try. From what you describe, it sounds like the coil is being fed by the starter solenoid on the fender well. Still, if you have done as I suggested with the jumper directly from the battery positive terminal to the coil + terminal the vehicle should run unless you have a few wires in the wrong place. As previously suggested, recheck your firing order, not only the sequence ,but also the direction of the firing order with the wires on the dist cap. Check which way the rotor turns ,Clockwise- or counter clockwise and your firing order must go in the same direction as the rotor turns. Did you remove the dist. assy? If so, are you sure if has been reinstalled correctly? These are the little things that separate the men from the boys. If the dist is one tooth off it might start ,but will lack power and may not even start. Lets see if we can get past this part, OK,,,hanky:)

Again, appreciate the help.
I did remove the dist assy.
I have verified the correct firing order, with all plug wires being correct and snug. I have struggled a little with trying to get the dist back in the correct place, so this is where I am at right now. I pull the #1 spark plug, rotate the engine to TC "0", place the dist assy back in so that the rotor is facing straight center back towards the carb.
Is this correct??????

If I were you I would refer to a Haynes or Chilton manual for a little assistance; they are about $16 at most any auto parts stores. If I were to try it "blind," I would put the engine at TDC (make sure it is on the compression stroke and not the exhaust stroke) and turn the distributor so the rotor is pointing at the #1 plug terminal. You will most likely be able to get it running like this, but you will still need to put a timing light on it and set the timing porperly in order for it to run well. Some vehicles use advanced timing as a standard, which you would need to set it to (this is where the handy manual comes in to play).

Bullitt has given you some good advice. I have had occaisions where the distributor was one tooth off and you could not get enough movement out of rotating the distributor body with the timing light because the vacuum advance unit limited your travel. That is why it is very important to get that distributor installed correctly. Be patient, and we will help get you through the correct procedure if you cannot get it done with the manual. ,,,,,hanky

I appreciate your help, Thank you very much for the suggestions. I have been trying to get the distributor dialed in. The Chilton book I have is a little unspecific about it.
I have it placed in a posistion that seems to sound the best when attempting to start, and again it almost starts-yet dies when I pull the key back. I moved the dist one tooth back and one tooth forward, and I think it is in the right spot now.
A few things I have noticed, when I switch the pos and neg wires on the coil-there is no difference in how it cranks/tries to start???
Also, it has a TFI-IV on the distributor. I had it tested, and it tested good.
It seems so close to starting, yet??????