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Discussion Starter #1
Ok, I just installed a 350/400HP crate engine and cannot get it to run right. It idles ok, but when you put it in gear it it pings and diesels when you shut it off. Also, when you stomp on it ther's a dead spot, it runs ruff and even backfires sometimes. The smell coming out of the exhaust is eye burning strong. The timing is all seems to be set correctly. Any suggestions anyone? Thanks, Gary
 

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The pinging is likely a timing issue. The dieseling is likey a carb issue (throttle blades too open at idle) which could be symptom of bad timing.

Tell us how you set the timing?

Also, is it possible the harmonic mark and the pointer on the timing cover are a mismantch?
 

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Discussion Starter #3
The timing is set at 32 degrees at 3000 rpm, which is what they said it supposed to be set at. I suppose it's always possible that the mark is wrong, but supposedly it was set and dialed in before I got it.
 

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It sounds like the distributor is off a tooth. Was it already installed when you got it.
 

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Yea, it was installed when I got it. Not sure if the guy who installed the motor pulled it out or not. I'm a little upset with him right now and not sure if he would even be honest with me.
 

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i had to change the springs on my distributor to get it to advance the vacumn and idel right, its a timing issue..
 

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First thing is to double check the timing your self. Then like knightmoose said the springs in the advance may be coming in to early and at idle its bouncing in and out. You should see this with a timing light..... Then adjust your idle down and check your float levels and adjust your fuel mixture screws then set your idle for best idle.
 

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If it's a 350 with 400hp it likely has a pretty decent cam, which means you need to do some serious timing work, initial, curve, total, and vacuum advance.

Take the cap off, turn the motor to COMPRESSION stroke on the #1 cylinder, and post back where the distributor is pointing. It is VERY easy, even for us big time gear heads to be one tooth off, I bet it is one tooth retarded from what you posted.

If it's not, disconnect the vacuum advance, set initial timing to 16*-20*, re set idle speed, and go from there, don't worry about the vacuum advance if it's equipped until you figure this out, that's a whole different story.

Your total timing can still be correct, even though you are a tooth off.

One way to tell if you are a tooth retarded is advance the distributor A LOT and see if it idles any better, if it does, you are at least a tooth off.
 

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I would shoot for 36-38 degrees advance on your timing... Its also very possible that during shipping that the timing could have been disturbed if the engine got knocked hard or dropped....How much play does the rotor have in it?
 

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Where does this "one tooth off" nonsense come from? You can time a car perfectly regardless of where the distributor is dropped. Which gear is engaged when the dist is dropped, isn't relevant. Timing is the relationship of the cap to the rotor.
 

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Where does this "one tooth off" nonsense come from? You can time a car perfectly regardless of where the distributor is dropped. Which gear is engaged when the dist is dropped, isn't relevant. Timing is the relationship of the cap to the rotor.
Basically you are saying if I go out to my car and pick up the distributor, and move it one tooth over, it will run perfectly fine?

It doesn't matter where the rotor is pointing (many of us like it pointing to the #1 though), as long as the #1 is at TDC on the compression stroke...
 

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Where does this "one tooth off" nonsense come from? You can time a car perfectly regardless of where the distributor is dropped. Which gear is engaged when the dist is dropped, isn't relevant. Timing is the relationship of the cap to the rotor.
most people like to keep it correct and put the number one plug wire where it belongs on the cap

i have just dropped the distrib in before and fired the engine up, ut i always went back and corrected it
 

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Your total timing can still be correct, even though you are a tooth off.




What? That only has to do with the position the dist is in. Timing is timing.
 

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Basically you are saying if I go out to my car and pick up the distributor, and move it one tooth over, it will run perfectly fine?
Yes, if you then set the timing with a timing light. The vacuum can will just point in a different direction.
 

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I think the "tooth off" comes in because people (me included) want the distributor to be in the factory position, which is, more or less, with the vac can pointing 45° across the engine compartment. In reality, being a tooth off becomes an issue because because you may not be able to rotate the distributor cap enough to get it timed where you want it. So, at least for me (especially since I have a large-cap HEI), it became a trial-and-error process of re-aligning the oil pump shaft and dropping and/or walking the distributor to get it so it would drop where I wanted it.
 

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You could have a drunk monkey drop the distributor into place. Then somebody who understands timing can set the timing to specs.

Like I asked, I'd like to know where the "one tooth off" nonsense comes from when diagnosing engine problems.

Yes, the AIM, for general assembly purposes, shows the basic layout for the plug-wire routing and the position of the vacuum advance unit. But one tooth either way or two teeth, or 6 teeth, etc, doesn't matter as far as setting timing.

Timing is the relationship between the distributor cap, plug wire position, and the rotor. Teeth on the cam or distributor gears play no role whatsoever with regard to timing an engine.
 

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Agreed. But if you're six teeth off, chances are you won't be able to rotate the cap enough to get the timing right because there will be an interference somewhere. Of course, as you imply, the wires can just be indexed differently on the cap to effect that result, but most people don't do that. So, they may crank it to a certain spot BTDC on #1, drop the distributor in, and not realize that because they didn't line up the oil pump shaft properly (and so the rotor isn't properly pointing towards tower 1 on the cap once fully seated - again, assuming they are not re-indexing the wires on the cap), the engine runs rough or improperly because the timing wasn't verified with a light.

So, as I understand it (and I may very well be mistaken - but I eventually got my car to run correctly timing-wise once I understood what was happening), they can then re-orient the oil pump shaft so that once the helical gear meshes and the distributor fully seats, the rotor is then pointing towards tower 1 in the position in which they want the distributor oriented (i.e. tower 1 typically clocked around 6:30 or so - which puts the vac can approximately 45* across the compartment).

But, if you're only one tooth off, then, yes, the quick and easy solution is to rotate the cap enough to properly time it (if you can). But at that point, you're just the "any monkey" that can drop a distributor in... like I used to be. :) :D
 
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