Help - I turned my truck into a backfiring machine!

[MattPSU]

I had my whole front end disassembled down to there being nothing but an engine on the frame. I pulled the everything off the front of the engine and I removed the intake and valve covers. I cleaned and painted the engine and then I replaced the valve covers and I cleaned up, painted and replaced the intake. Put everything back together, went to start it and it was backfiring through the exhaust. Seemed like on every cylinder. After searching the board for answers, I thought maybe I had the distributor off by 180 deg. (Of course I forgot to mark it when I pulled it out.) I turned it 180 and now it's backfiring out the carb. Wouldn't start either time...just backfires. Any ideas what I need to do to get this thing fired up? Am I off a tooth? Was I off a tooth before?

350/350 Auto w/ Q-Jet

Thanks in advance - Matt

[Dnrice]

You still have a timing issue. I have a feeling you need to advance some more. Move distributor clockwise.
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[Dnrice]

And you may be off a tooth and TDC is now not correct.
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[Mister-B]

Try what the other guys have suggested, but also make sure the spark plug wires are connected to the right spot on the distributor, and the correct spark plug. There's a firing order. You can google what it is for your engine. This happened to me about 15 years ago with a 350 small block. I unplugged all the wires at once to change my plugs, and didn't know they had to be plugged exactly how they were lol, so I ended up getting them wrong, and it backfired like you described
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[DnHolland]

Do you have the correct balancer and timing tab on the timing cover? Do you have access to a timing light?

[DnHolland]

Also, what kind of distributor do you have? HEI or points?

[MattPSU]

Thanks for the responses, guys. Let me answer your questions...
Points. Stock balance and timing tab. I didn't remove either when I cleaned painted.
Don't have a timing light, but I can always pick one up or borrow one if needed. I'm pretty sure my wires are ok. I left them on the distributor cap and numbered the wires before I removed them from the plugs. I did buy new wires, but I replaced them one at a time, so I don't think that's the problem. I could be wrong though. Wouldn't be the first time. New spark plugs too - same as what came out and gaped the same. - Matt

[ole dollor]

the firing order is 1 8 4 3 6 5 7 2...1357 is on the left side (driver) and 2468 are on the right side (Passenger ).on a point dist. # 1 plug wire should point to the
#2 cylinder of the motor....then wire clock wise ..hope this helps..

[72 K20]

I have a feeling you need to advance some more. Move distributor clockwise.

Actually,, turn the distributor counter clockwise for more advance .

[Robznob11]

Id start from scratch. Pull #1 plug rotate piston to tdc, drop distributor in with rotar pointing at #1 then wire like said above. Then you gonna need a light. You can use one from auto zone for free good luck"!
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[Dnrice]

I think counter clockwise is correct. Sorry about wrong info. I almost bet you that you are off a tooth which makes your timing tab off.

[Low Elco]

Check that your freshly installed valve covers aren't binding the rocker arms. BTDT.

[GASoline71]

Verify that the timing mark on the balancer is in the right spot as well. The outer ring on the balancer is held in place on the hub by a rubber ring. Over time the rubber deteriorates, and oil can get in there and cause the outer ring to spin on the hub. Bring the engine to TDC and verify that the timing mark on the balancer is pointing to zero on the tab.

Gary

[DnHolland]

Originally Posted by Robznob11

Id start from scratch. Pull #1 plug rotate piston to tdc, drop distributor in with rotar pointing at #1 then wire like said above. Then you gonna need a light. You can use one from auto zone for free good luck"!
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That's what I was going to say. Let us know how it turns out.

[MattPSU]

Originally Posted by DnHolland

That's what I was going to say. Let us know how it turns out.

- That's the new plan. I picked up a timing light after work and I'm about to head to the garage to start fresh. Stay posted! - Matt

[MattPSU]

OK - I got the engine back to TDC and removed the distributor. Here's some pics of it back in place. Does this look correct? I want it pointed at toward the #1 plug, right??? - Matt

[CC69Rat]

Isnt that pointed at #2 ? See the "8" and "6" on your intake? Is that sitting at TDC?
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[ole dollor]

Originally Posted by MattPSU

OK - I got the engine back to TDC and removed the distributor. Here's some pics of it back in place. Does this look correct? I want it pointed at toward the #1 plug, right??? - Matt

if its on the timing mark, than it is setting right where it should be. if it wont crank there, take it out and turn it 180% and it will start....

[MattPSU]

SUCCESS! It fired up and no backfiring. It wouldn't stay running - it ran out of gas, and of course, after adding some gas, I couldn't get it to start again - dead battery. Jumping it didn't help at all. The battery is old (there's a sticker on it with 1/00) and I had plans to replace it, just not yet. Don't you love when fixing one problem reveals another???

Thanks again for all of your help guys! Yet another reason why this board it AWESOME. - Matt

[GASoline71]

The #1 cylinder is on the drivers side front. Your pis show the rotor pointing towards #6 or #8.

Drivers side is 1-3-5-7, passenger side is 2-4-6-8.

Gary