I just finished rebuilding an 82 I6. I had the transmission rebuilt, redid the entire suspension and had the engine rebuilt and painted. I changed the 1 bbl to a holley 4 bbl with a clifford 6=8 intake. Everything else is stock. I got everything put together today. The only real change I made was there was a single wire (a ground I think) that went from the alternator to the carb. I removed this as I did not see any where to attach it to the 4 bbl. I hooked everything up today primed the carb and tried to start the engine. The starter turns and I get the occasional backfire / chug put I cannot get the engine to turn over. I am running a deep cycle battery and even hooked up and tried to jump the engine from another vehicle but it just will not turn over. i am looking for any kind of trick you can think of. Thanks.

 

That wire from the alternator to the old carburetor was the choke wire. It runs from the stator terminal of the alternator to the choke. It's not ground, it's a 14V AC signal produced when the motor is actually turning.

Consult the installation instructions for your carburetor, but most aftermarket carbs have you run 12V hot-in-run to the choke. Alternatively, you can get away with hooking the old choke wire up as well and it will do pretty much the same thing. Lastly, if your choke cap has two electrical terminals instead of one, don't forget to ground it.

I'm not saying this is why your motor won't start, but it does answer your question about the leftover wire. It could be a choke issue, but it could also be a fuel delivery or timing issue as well.

 

The backfire might indicate a timing issue. Check the dizzy to make sure it was reinstalled where it should be.

 

Check your firing order.
Is dist 180deg out?

 

The distributer is back in the exact same position it was when it came out. The firing order is correct as per diagrams and the photos I took before taking everything apart. The only thing I am not sure on is I might have switched the wires on the coil. Not the one to the distributer but the two little connections. Could this cause a problem? On my carb I hooked the positive connection up to the old carb wire and the ground is connected back to a screw on the carb itself. Any other ideas? I usually get about 3 or 4 chugs on the engine as it tries to turn over. I hear the starter going just fine. I had the battery charged. I have the old manual fuel pump on the block but I poured fuel down the line into the carb and when I engage the throttle I can hear fuel going into the carb.

 

No, you have the coil all wrong. There's no way for it to fire the way you have it. The coil positive comes from a special length of resistor wire in the dash harness. It drops the 12-14V running voltage down to 7-9V, which is what the coil is rated for. If you hook straight 12V to the coil, you will fry it very soon. Often the length of wire is called a "ballast" resistor. It's usually a fat pink wire and sometimes labelled "do not splice."

The coil negative on an '82 comes out of the Duraspark module (green wire). It is a pulsed signal that the Duraspark uses to "fire" the coil. If you just hook the coil to ground, the coil will always stay "charged," the coil negative will never be open-circuited and the coil will never discharge through the plugs. It's the same idea as breaker-points only it is done electronically through a power transistor.

For your reference, here is a Duraspark diagram I grabbed off the internet. It's copied in so many different places that there is no need for me to credit the source.

 

I switched the wires, installed the carb wire from the sta terminal to the carb, and tried to tune in the timing as close to TDC as possible but it still will not turn over. It seems to be getting closer but still nothing. Should I try some starting fluid or could that hurt things. Will the fuel pump continue to pump even when the engine is not running (ie as long as I try to pump the engine.

 

I also painted the entire engine block and the frame. Could this problem be that there is not a good ground from the engine block. THere is a single wire from the drivers side of the block to the engine fire wall. I painted the entire engine compartment with rustoleum? Could that be a problem?

 

Did you not read my post? You have your entire ignition system installed incorrectly. It's not just a matter of switching the wires. What is the point of asking for advice if you're not going to take any?

By the way, setting the timing to TDC is incorrect, you need it BTDC to get in the ball park and then you can time it dynamically once the engine fires.

 

FMC400.

I did not spell out everything I did to save time typing. But yes I read your post. I went from the battery all the way through each wire to the ignition, through the ignition module to the distributer and the coil and made sure it all in agreement from that diagram you posted. I chased each wire and the only difference I found was originally that I had green wire from the ignition module to the BATT terminal on the coil. "SO I SWITCHED THE WIRES" on the coil, yet no change. Now i did remove the distributer and made sure to mark both the block and the body of the distributer so I could put it back correctly. I cleaned all the terminals, scraped off all the carbon build up off the points, and cleaned the rotor. However does the gear at the bottom of the distributer have to seat at a particular point. It seems to only line up in one place but I spun it multiple times when I was cleaning it.

I had the battery charged and will get the timing adjusted to 6 degrees off TDC as that seems to be what most people are saying as best. If this does not work I am just going to have to take it into the shop.

 

Okay, sorry for the misinterpretation. When you said "switched the wires," I was under the impression that you just swapped the coil positive\negative around.

Here is something else you should try. Have a buddy crank the engine while you read the voltage at the negative coil terminal (put one probe at engine ground and the positive probe at the negative terminal of the coil). You should see it flash between 0 and 12 as the module tries to fire the coil.

Also, do try and get your timing around 6 if that's possible just from cranking. That will at least get you in the ballpark to get the motor to fire in the first place. Best of luck.

 

Thanks its all working now. Turned out I fried the coil and had the distributer installed out of sinc. The truck is now smooth as a whistle. Thank you for all the advice it sure helped.

 

Glad to hear you got it worked out!