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Discussion Starter #1 (Edited)
So I'm about ready to get real friendly with my mini-sledge! I've got a 69 mustang with a 514, yada yada blah blah a lot of go-fast engine parts. It was running decent over the summer and I moved. It was just parked for about 2 months being started and runs every week or two. I decided to pull the motor apart to inspect the internals before adding more stuff in the spring. Like I said, was running decent. The time before I pulled it into the garage it started rich smoking and running poor. The night I pulled it into the garage I drove it about 10 feet and then had to push. Tore the motor down everything looked good. I go to put it back together and now it barely starts if at all, if it idles its at 2500rpm, when I give it gas it may or may not react, sometimes it revs sometimes it dies, when it does Rev its backfiring out the exhaust and when it tries to die at low rpms it shoots flame out the Carb.

Im going insane here. The cam timing was dead on, rotated, still dead on. Ignition timing is reading perfect. Spark plugs are new and gapped perfect. The passenger bank plugs are reading quite rich and the driver bank is reading slightly rich. I went up to 6k feet elevation so I was expecting rich because I haven't retuned it yet. I don't know what's going on. I have a 7al-2 box, Mallory promaster coil, Mallory unilite distributor, Mallory pro Sidewinder 8mm wires and autolite 45 plugs. Any advice? This all pretty much happened while the car was sitting. Oh and sorry for the long explanation
 

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Discussion Starter #2
Oh and I know my firing order and plug wires are correct. It has been checked by me and three other people half a dozen times. Been there done that before. But that's partly why I'm confused because that's exactly how it running
 

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Some of this modern gas will go stale and start to gel up in a couple of months.
 

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Discussion Starter #4
All the gas is new and I cleaned the Carb, which was already fine.

My next question is, when I can get it started and above 1000 rpm I noticed the timing mark never changes meaning no timing advance. It just stays at what I set my initial timing to. And I've had it to 4000 with no change. I've been trying to read up on mechanical timing. But its just not sinking in. I have a malllory unilite distributor. Could a problem with my mechanical advance be causing my issues? They started. When I pulled the car apart so maybe I bumper the distributor and changed something? Can someone give me a lesson for dummies on checking and setting the mechanical advance?
 

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Discussion Starter #5
All the gas is new and I cleaned the Carb, which was already fine.

My next question is, when I can get it started and above 1000 rpm I noticed the timing mark never changes meaning no timing advance. It just stays at what I set my initial timing to. And I've had it to 4000 with no change. I've been trying to read up on mechanical timing. But its just not sinking in. I have a malllory unilite distributor. Could a problem with my mechanical advance be causing my issues? They started. When I pulled the car apart so maybe I bumper the distributor and changed something? Can someone give me a lesson for dummies on checking and setting the mechanical advance?
 

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Pull the cap and give the rotor button a good twist clockwise. Maybe the mechanical advance is stuck from sitting. If it 'breaks free' then tear the dizzy apart, clean and lube the advance assy. I assume that you're not running a vacuume advance. If you are then you've got problems there too.
Rob
 

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Discussion Starter #7
Pull the cap and give the rotor button a good twist clockwise. Maybe the mechanical advance is stuck from sitting. If it 'breaks free' then tear the dizzy apart, clean and lube the advance assy. I assume that you're not running a vacuume advance. If you are then you've got problems there too.
Rob
No its not vacuum. I did that and it wasn't stuck but it was really stiff. So I took it apart and there was a brown waxy buildup on one of the weights. So I cleaned it out and put it back together.. but I think as far as the running part, Im thinking my powervalve diaphragm is blown. It runs pretty good when I have my fuel pump off and its about to run out of gas. As soon as I turn my fuel pump back on it bogs down. And it did seem to be pumping a lot of gas in when I was running the linkage by hand. So I'm gonna try rebuilding the Carb and try it again.
 

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Discussion Starter #9
Double check the float level & seats. Sounds like you are dumping fuel while your pump is on.
I do think its dumping fuel but nothing to do with the pump. I can have the pump off and the engine wont pick up until its almost out of gas. Once it does run out of gas I can flip the switch for a second and it will pick back up. But if I have the switch on for to long or fill the Carb when it dies it will sit and bog for 5sec til it gets low on gas again. Ill play with my float level but does the holley speed demon 850 have a power valve diaphragm? Im not too familiar with this Carb. But I know the whole car was sitting for almost two years before I bought it so I was thinking the diaphragm dried out.
 

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Either the float level is too high in one or both bowls, you have a ruptured power valve, leaking gaskets or the mixture screws are too rich. I'd bet on the power valve or gasket(s) on the metering plate. The cork ones dry up and shrink quite a bit.
Rob
 

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Discussion Starter #12
I havent been on in a while but I figured out the problem.my rocker caps got switched around so I needed to readjust my valve lash. I readjusted them and its running good again
 
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