[Ben]

I have a 80 turbo TA that the 301 was taken out and replaced with a 75 400. A little about the 400 (I was told from the previous owner)it was bored 30 over,comp 280 cam, RPM intake, Holley double pump & an aftermarket distributer.
1st - The alt. does not charge at idle,when you gas it up to about 2500 RPM it starts to charge & will charge at idle till you turn the car off then it does the same thing until u rev it up. It is the 70 amp alt. 2wire plug-in with 2 red wires on the back also

2nd - Car idles funny (no its not the cam) The vacum adv. when you hook it up it seems to have a vacum leak. The timing is set at 8 deg, when you hook it up it goes to 33deg, now it does have a adj. vac. adv. but if I shut it all the way(close it off) it runs the same as unplugged. It also backfires through the carb sometimes when you first start it.

Hope I have explained everthing that I needed to for some help.

[2manyT/A'S]

Sonds like you need to repair or replace your alternator (or just remember to kick it in before you start driving or turning on electrical accessories)

ALSO,you might want to pull the cap & check your centrifugal advance. The weights are probably stuck in the advanced position. Some lube/cleaning would probably help.

What make & style of distributer is it?

[Ben]

The distributer looks new dont know what kind it is,it has a red cap..lol I have looked on ebay and looks like a $50 distributer 50000 volt coil

[2manyT/A'S]

I've heard some "not so good" stories about those CHEAP chinese knockoff HEI's.

You are probably better off with a used original Delco.

[Thumpin455_GTO]

If you are getting full advance when you connect the vacuum line, then you are connecting it to manifold vacuum. There have been huge debates on where to hook it up, but the factory used timed vacuum. In other words, its the port on the carb that doesnt have vacuum until the throttle blades reach a certain point. You can find out which one does what by letting the car idle and putting your finger over the port, the ones that pull your finger are manifold vacuum. Give it some throttle and see what the 'dead' ports are doing. When you get one that has vacuum after its given throttle, thats the one to use.

Backfiring through the carb at start up is one of two things. Either retarded timing or a valve train problem. If it doesnt do it all the time, its probably not a valve or flat lobe on the cam. My guess is you have the timing retarded too far and its popping through the carb. If you are using a light and its showing advanced, your balancer might have slipped. To find out if that is the case you need #1 piston at top dead center with both valves closed, then see where the marks are. It should be directly in line with "0" on the pointer. If it isnt then the balancer needs replaced.

I have also had bad intake gaskets cause a backfire through the carb, but they did it under load and not at idle.

If it has a red cap and its shiny, it probably has an MSD/Mallory cap or is an MSD/Mallory distributor. Post a pic of it and maybe we can tell what it is. It could also be a summit distributor, and they arent that bad really.

["QUICK-SILVER"]

Check the brown wire in the plug-in on the alternator for power, unplugged, key on, engine off. Lack of power on the brown wire and you have to rev the engine in order for the alternator to start charging.

Slow timings done been mentioned and 8° is TOO SLOW.
"75" 400 initial timing should be set at 16°. Aftermarket cam and performance tune-up, initial timing may go as high as 22°, how far past 16° you have to go will be trial and error till you find where the engine runs best.
Setting initial timing, the engine needs to be idling low enough that the centrifical advance isn't moving and vacuum advance unplugged.

Timing, initial and centrifical need set/adjusted where the engine runs the best. Vacuum advance comes after WOT timing has been determined and needs hooked up and adjusted for best cruise.

[Ben]

Ok I finnally was able to check everthing, there is a red and black wire on the alternator no brown but there is power to the red wire when key is on.
For the timing it didnt do a whole lot to advance it othen then speed up idle and harder to start.
I also check it both ways on the vacuum ported and ported when WOT & checked the centrifical weights and all is good.
Here is a pick of the alternator & distributor
is there a possible chance the who ever put the motor together didnt get the cam gear set right (didnt get the dot set at 12) maybe 1 tooth off. If so is there a easy way to chech that out without pulling the front cover off?

["QUICK-SILVER"]

Originally Posted by Ben

Ok I finnally was able to check everthing, there is a red and black wire on the alternator no brown but there is power to the red wire when key is on.
For the timing it didnt do a whole lot to advance it othen then speed up idle and harder to start.
I also check it both ways on the vacuum ported and ported when WOT & checked the centrifical weights and all is good.
Here is a pick of the alternator & distributor
is there a possible chance the who ever put the motor together didnt get the cam gear set right (didnt get the dot set at 12) maybe 1 tooth off. If so is there a easy way to chech that out without pulling the front cover off?

The red wire in the plug-in should be hot all the time, key on or key off. The one that looks black should be hot when the key is turned on, check fuses, it might even say choke on the fuse box.

You need to set the timing at least up to factory. You will have to idle the carburetor down and re-adjust it. If it's idling too fast when you check timing, the centrifical advance will be trying to come up, so it needs to be idling slow when you check it.

One tooth on the cam will be hard to check without pulling the timing cover but you can get kinda close.
If you know the valve timing event (exhaust close,intake open), you can turn the engine by hand, with drivers valve cover off, watch the #1 intake and exhaust valves. Turning the engine slowly to TDCE (top dead center exhaust not compression) you can watch the exhaust valve close and intake valve start to open.
The timing mark on the balancer will go past 0° and the valves should close and open close to cam specs. Valve opening and closing events are in crankshaft degrees. If you watch the mark on the balancer, the timing tab on the timing cover and rocker arm and valve movement, you can check cam timing pretty close. A tooth off will show up if the timing mark on the balancer is in the right place.

Holley carburetors will backfire cold cranking if the choke isn't working. Backfiring could have busted a power valve and causing your idle problems.

Check it out some more and post back.