Hey everyone, new here. I have 87 w150 with 318. Started off factory when I had it, ran fine with no issues. It was a daily driven truck. Just had no power with the factory carb and intake. So yanked the engine and put new cam, lifters, timing chain/ gears, intake, 4bbl carb, headers, fuel pump and vacuum advance distributer. All wires, cap and plugs also. It has been slow process as I was doing it all when I had the time, well I got it all back together and into the truck roughly 2 months ago, got it fired up, and she's got a constant back fire out of the headers. Fires out of the carb when I shut it down.

When installing cam, chain and what not, I replaced the gears and cam back in position I pulled the stock from. Both keys and timing marks facing the same way as they were with stock cam and gears. I may be over thinking, or over looking at this point, so I need other opinions please! And input advice will be greatly appreciated!

 

What's the timing set at and where do you have the vac for the distributor going to? Little more info would be nice, What carb? CFM? What distributor? Did you double check the wires(going to correct cylinders)?

 

Distributor vacuum was going to left side of pcv vacuum port, but I was told it goes on the right (driver side) so I will give that a shot. It's a factory distributor from local parts store. And I believe it 650. As for timing I had it on 0 I believe but It's been awhile since I have been able to mess with it so I will get back a little later today with better details.

 

What make carb? The distributor vac advance needs to go on a port on the carb not manifold vac. Doing that will give full advance at idle.

 

Edelbrock carb.

 

I apologize, it's 600 cfm. Going to start over with timing tomorrow, putting wires back to place on cap by the book. Rotating them a couple months ago cut the back firing out a lot. I have video of it running before and after rotating the wires.

Now possible to get a quick run down for setting timing?

 

Ok sorry for all the inconsistency, had some time the afternoon, so I started over on timing, brought #1 TDC compression stroke, harmonic balancer is at zero. Checked under my cap and I now remember why I rotated my wires, the rotor is pointing between #3 and #4 on my cap! #1 on my cap is facing front of engine. Why in the world would this be? What did I screw up?

 

Peobably got the oil pump/dist drive gear in wrong.

 

Yeah! Even i made this mistake. I forgot to check it after putting it in. You either have leave the dizzy in the position it's in(if it clears everything at #1) or reposition the distributor/oil pump drive gear. Disconnect the distributor vac line going to the manifold vacuum!!!! Look at the documentation you got with the carb and it will show you where to put it(on the carb).

 

Alright, like a dummy and as impatient as I am, I had my firing order all out of wack. (Pretty embarassing) so I need to slow myself down!

As for my rotor position, I have the pump shaft turned a few teeth, so I rotated my wires, fixed my firing order. Still have room to time so I left shaft alone. She's running beautiful!!

My vacuum advance is on the carb. On the front of the edelbrock, driver side. (Where their book recommended)

Thank you everyone for all the help!