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Old 06-17-2004, 08:17 AM
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back fire

I just put a fresh 350 in a truck. I got #1 up on the compression stroke. Put the distributor in with the rotor pointing toward #1 cylinder. The cap is on, and I will try to explain this right. From the place on the cap where the battery wire hooks up going clock wise, #1 is on the 2nd post. When I try to start the engine to break the cam in, the engine just backfires really bad. What do I do?

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Old 06-17-2004, 08:21 AM
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Recheck timing and check valve timing as well. Make sure the rockers aren't to tight if you working with a adjustable set up.
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Old 06-17-2004, 08:31 AM
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I'm assuming this is an HEI distributor. My understanding is that #1 is the 'first' post clockwise from where the battery wire is connected.

Truthfully it is really only where the rotor falls at TDC on cylinder one. So if you installed the distributor body with the rotor moved around a bit, it could fall to any of the posts you choose. The back two posts towards the firewall are much easier to deal with regarding the wires if you make the first post clockwise from where the battery wire is connected your #1 position.
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Old 06-17-2004, 08:41 AM
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I haven't set the timing yet. I was told to fire the engine, get it to where it would run, idle it up for 20 min, to break the cam in, and then set timing.

So your saying if I move the wires back one it might cure the problem.
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Old 06-17-2004, 09:48 AM
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Do what johnsongrass1 posted. To get the right post for #1, get #1 TDC compression stroke. Pull the distributor out, if it is vacuum advance have the advance canister on the passenger side of engine some what pointing to that side. Then point the rotor toward the front bolt on the carb mounting bracket driver side. Drop in distributor, the rotor will rotate a little, finger tighten the hold down bolt, you should be able to rotate the distributor. Take note of direction rotor is pointing. place cap on distributor, the post that the rotor is pointing to is #1. hook wire starting there with #1. Engine should fire if everything else is right.

Good Luck
GOD BLESS

Joe
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Old 06-17-2004, 10:05 AM
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Quote:
Originally posted by savman1

So your saying if I move the wires back one it might cure the problem. [/B]
No, I'm saying that it 'could' be that you are off a post or two. The sure fire way to find out is what CamaroGuy said.

Pull your plugs out, rotate the engine to top dead center on Cylinder #1, take a look at where your rotor is pointed (just take the distributor cap off). Whichever post that is pointing to is your #1 post. Put the cap back on, the plugs back in, and run your wires accordingly.
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Old 06-17-2004, 02:55 PM
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Timing

Doc Here

First, as all have said, bring #1 up TDC on Compression, Your rotor Should be 5~ O'clock (for a 63-74 engine) on the cap ( 7 O'clock on 74-up engine) If that's not there your out of time. Reset the Static timing.

Pull and Check the Cap for: Lifeforms living inside It (especially If it's been sitting awhile) Water or moisture creating crossfire tracks inside it.

The Firing Order Will Be, Clockwise, 18436572 verify this is the case, reassemble and try again.

If you still Get Backfire Then Verify that the Timing Chain hasn't Jumpped time. Or been installed improperly.
(Remember: Dot to Dot on the Gears is #6 TDC Compression, not 1 , Dots pointing at 12 o clock is #1 TDC compression)

Ensure All Valves are properly Adjusted, Even too loose if necessary for the first start, (Hydraulics will Fill under first Crank pressure and close the gap possibly hanging one or more open) Make Sure ALL lifter Pushrods are Seated Properly in the lifters.

If all that Checks Out, Then I'd look for a REALLY Big Induction leak, or bent, broken or otherwise folded spindled or multiated Intake valve (s)

Follow that and you should find your Problem.

Regards,
Doc

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Last edited by docvette; 06-17-2004 at 03:17 PM.
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Old 06-17-2004, 09:57 PM
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btw - I have a poor memory.

Just walked in the door from wrenching in the shop and sure enough, #1 is two posts over from the battery connection on my hei (which is where is supposed to be). Wanted to make it a point to dispell any misinformation I might have put out in the world.
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Old 06-18-2004, 05:12 AM
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Mine is one post over. It just depends on how far the housing is rotated when you drop it in and where the rotor is pointing. I could have my #1 pointing to the fire wall put the cap on and start at the post next to the firewall and work my way around. It will still fire run and never tell a difference. All that matters is that you put #1 plug wire where the rotor is pointing with #1 TDC. You also have to take into consideration of the vacuum canister and that it will not hit the carb or firewall when trying to time it.
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Old 06-18-2004, 08:58 AM
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Right, but I said that with the #1 post being one post over from the battery connection the wires that come from the back two posts of the hei distributor are easier to deal with (on a tri-five this is right up against the firewall). #1 would have to be two posts over to make life easy in regards to running the wires for cylinders #6 and #5.
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Old 06-18-2004, 03:58 PM
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Wire Nightmare

Quote:
Originally posted by camaroguy_1967
Mine is one post over. It just depends on how far the housing is rotated when you drop it in and where the rotor is pointing. I could have my #1 pointing to the fire wall put the cap on and start at the post next to the firewall and work my way around. It will still fire run and never tell a difference. All that matters is that you put #1 plug wire where the rotor is pointing with #1 TDC. You also have to take into consideration of the vacuum canister and that it will not hit the carb or firewall when trying to time it.
Doc here

Camaro Guy is Correct about Placing #1 and subsequent firing order at any Spot on the Dial and it will run fine.

HOWEVER: From personal Experience, I always try to stay In the 7 or 5 O'clock area, The reason, The poor Next Guy that gets the engine or car and is not privy to that info will go through H*LL if he tries to wire it, or The tune up guy looking for #1 to hook up the timing light is not gonna know until he traces the wire down, and the begin to wonder why it's where it's at. (At an hourly rate)
Or the Smog guy trying to Verify Timing for the test.

I have bought Donor Engines from the boneyard over the past 30 years or so and had one or two, this was done to, Of course the cap and wires are the first to get trashed when the wrecker pulls it.. Spent many hours running down problems I never had...Like Jumped timing Chain, Ect...

Just my opinion, Looking out for the next Guy, (me usually Being the next guy...)But If you don't have Anything blocking the Advance / Retard Arc area, I'd Stay at 5 or 7.

Doc
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