I have a 1985 F150 XLT Lariet
Rebuilt 351W
Ported heads
Edelbrock RPM AirGap
Edelbrock performer-link timing chain and gears.
*Advance 4 degrees.
Carter AFB carb 650 cfm
2 inch open plenum carb spacer
Bored .040 over

It will kick over like it wants to start but then it just goes back to cranking.
Anybody have an idea as to why it wont start? I've been on this for about a week now. It has spark. It has fuel. It has air.

 

Did it used to run and now it won't? Or are you trying to start it for the first time since the rebuild?

Yes, it needs spark and fuel and compression but in the proper proportions and at the right times... how do you know it has fuel and spark? What were your diagnostic steps?

 

This is the first run since the rebuild.
For spark, I ground the spark plug to the block and cranked it over and for fuel I took the line off at the carb and cranked it. The carb jets are working as well

 

So it could be a lot of things... start with the basics... verify #1 is at TDC on the compression stroke and the timing pointer indicates 0°; verify the rotor is pointing to the correct location (it's easy to be off one tooth on distributor installation and cause stuff like this).

I guess what I would do is have somebody try and start it while I turn the distributor both directions as far as it will go and see if the behavior changes.

 

I would try and advance it.
Sounds like you have a lot of intake volume.

 

Now it backfires through the carb. I aligned it to tdc and set the dizzy right at one.

 

Or, you could try it this way. Set the harmonic balancer to 12* BTDC and align the distributor rotor right up with number one. It would help if you had a junk distributor cap, could rip the #1 terminal out and look down the hole.

 

Sure you have the plug wires connected correctly to the dizzy?

 

So, you have your timing set at 0 degrees right now?

 

That doesn't sound right.
Upon firing a new flat tappet cam engine you want to run it at 2k or more for at least 20 minutes.

I usually set my static timing for 10-12°, fire it and hold the throttle open.
You don't want to be retarded, the truck could overheat during break in.

 

Given that it kicks and is now backfiring through the carb, I would remove the distributor and reinstall it one tooth off from where it is right now - probably to the right for the first try.

 

Ignition timing is synced to the crank.
It is possible the damper has slipped if it was reused.

Moving the distributor one tooth can help if you run out of room to swing it.

Comparing TDC #1 with the damper marks will confirm the ignition timing is accurate.

 

This is all assuming the timing gears and cam have been installed correctly - dots facing each other, for example.

I went through something like this the first time I fired up the 400, moving the distributor one tooth was the fix (the vacuum advance diaphragm really limited the available range of motion).

 

If the cam timing is out he is phqued anyhow.

 

Timing is set at 10btdc and no longer spits out of the carb. It kicks and try's but does not run. 😡