Good afternoon everybody, I am installing a new distributor in my 83 351W. I'm a little confused, I dropped it in at TDC and it's running but missing slightly. Do I need to move to 10 BTDC when installing the distributor? Thanks

 

It sound like you installed the distributor ok. What type of ignition do you have? If you have a vacuum line coming off the distributor, disconnect and plug this line. If you have an electronic module on the side of the distributor, trace the wires down until you find a sngle connector, called the spout connector an disconnect this. Then, using a timing light, set the timing light to the figure listed on the sticker located on your radiator core support or for your truck from a service manual.

 

Thanks for your reply, the radiator core support isn't going to help me out. I took out the EEC III system in part because it didn't allow for any ignition timing, idle mixture and choke adjustment. The main reason however was because when I got the truck almost all of the emissions related components were gone. The only operational part of the EEC III was the feedback carb and the Duraspark III distributor. It ran OK when it wanted to, sometimes it would quit but would always start again if I held my mouth right. Mileage was terrible, most all of the feedback components were totally gone. I put a Holley 2300 in and bought a HEI distributor withan external coil. I have a set of 83 light truck shop manuals, I can't find timing specs in the ignition section but it does show a drawing of the timing marks on the balancer set at 10 degrees ATDC. I tried that setting and she didn't seem to like it. I don't know if the picture is for the benefit of example or if that is the timing, it doesn't specify.
The distributor doesn't have a vacume advance, there is a ground wire for the distributor, negative coil terminal wire and a switched 12V. I don't know, maybe I have a dead hole/defective plug wire or something. It doesn't seem to make any difference whether I set the dizzy in at TDC or 10 degrees BTDC as far as the slight miss when it's running.

 

10 BTDC is a good general figure, but not a certainty. Given that your using an aftermaket HEI distributor, it's really hard to provide any meaningful advice. I would still look at the original calibration as a starting point.

 

kjay, the timing info that I've seen in answers to your postings has been right on. But my concern for you is that the rig has, as you say been partially converted to old school. I mean almost pre 1975 internal combustion. I too have a rig that was modded before my taking possession. Leaving any of the original emissions sub systems opens up many possible causes for your miss. The old manifold may have a bad EGR valve, EGR passages may be blocked by carbon, or the valve could be being held in an open position (= vacuum leak). All in all, its real hard to make tuning suggestions not knowing the full existent of the mods to your mill. Early (69-72 non emission) guides and manuals may be of help in your quest for specs.
Eliminate what you can afford to as a possible variable. Change to new plugs and wires, tune up stuff. Take a compression check (buy,barrow,rent a good gauge). Ask lots of clearly written questions here, and you should end up good to go.

 

Thanks XLnAK, I removed everything else that was left. EGR valve, EGR valve cooler, temp sensors etc. Everywhere there was a hole left by something is sealed. The intake has a carb on it and that's it, haven't seen that since HS! The only thing I haven't dealt with yet is the massive wiring harness left on the passenger side under the hood. I suspected maybe an open circuit could cause something to happen? I'm 99% sure there isn't any information being shared from under the hood to the dog house. Thanks for the reply, it was very informative for me.

 

Kj, You are very welcome. I don't get to chat here as much as I have in the past. I still have my 83, but she needs a valve job on one head. Thats along story. But at any rate I really enjoy the older motors and all that cam with em ( or didn't. lol). Seems we as a group of consumers, have given up a great deal of owners rights concerning self maintenance and even responsible moddability of our power-plants.
Hope to see ya around here. FTE, is good company.

 

I hear ya, the old school conversion is complete as of today. I don't think there's any thing left that I can't work on myself with the help of FTE members. Not to say I couldn't have been walked through an EEC III issue but I would have been peeing in the wind with 75% of it hacked out before I even got the rig. Now, I feel 100% confident in my skill level to take care of the damned thing. Hope to see you around too.