Lol. Sorry Ned. When I'm frustrated, I shorten everything. Distro = distributor.
I have a stock HEI. Basically, I've done a lot of maintenance to the vehicle. Consider it 50K mile maintenance. I did this just to get rid of as many question marks as I could. Cap, rotor and plugs. I replaced the fuel injectors because, well, for the hell of it.
I have used a GM in-line spark tester and yes, it was yellow, not blue. Therefore, weak spark. In fact, very weak spark. That is why I am once again focusing on the distributor as a weak spark issue. I replaced the coil and there is no difference. Therefore, I have ordered (and overnight shipped) a new pick-up coil from Eckler's. I have also ordered a new Ignition Control Module. Why? Well, for the hell of it. It's cheap.
So, the pick-up coil is supposed to be here on Wednesday before 8pm. Hopefully, it will be here before it gets dark and I will get to install it. I really don't want to pull the distro, but we will see. TDC and all.
navy man, the "D" threw me off, plus ref to "primary coil." I thought you might have one of those gimmick boxes that people bolt/connect into the system, like MSD, whatever.
I may be wrong about the spark color IF using the GM tester. FSM does not mention color in that test, but does refer to "weak" spark other times. that test requires 25,000v to fire.
but...the HEI depends on a full 12Vdc at the ign coil/pickup coil. if there is resistance to the 12v supply, the HEI produces a weak spark. bad terminal connection, etc, can do it. the spark starts with the pickup, so if I were desperate, I would replace it -or do it anyway, as I did when rebuilding mine, which had no problems before or since.
some tips if you have never done a rebuild:
put timing mark at 0 on tab, with rotor pointing to front. it will be ABOUT a 11.5-5.5 mark on a clock face, just short of the six o'clock position.
make a mark/scratch, whatever on the dist base to manifold, so you can reset it close to correct advance.
the oil pump shaft will rotate CW -counterclockwise- when you remove dist, which is why you have to reposition it when re-installing.
NOTE: the shaft slot centerline will always match the rotor centerline, so that it will need to be at the same direction to drop the dist. in.
observe where the shims are under the dist drive gear before driving the pin out.
the pu coil has a thin C washer under it that has to be removed, using small knife blade, whatever. pack the opening under coil with a hard grease. spin the dist shaft to be sure the teeth do not touch teeth on pu coil pole piece.
most of it is self explanatory. the book says use clear silicon grease, thin, under ICM. you will get that or similar with the ICM.
you can align the pump slot using a long screwdriver so that it is ABOUT pointing between the 5 and 6 on the clock. before dropping the dist into the cam gear, rotate the rotor C
W 2/3 of the way toward the #2 firing tab on dist cap, because the teeth are spiral and dist. gear has to rotate to mesh. it will settle into place.
OR -with rotor pointing towards #2 as above, you can rotate the engine -I have used a 15/16" socket to turn the alternator bolt, turning engine backwards, and the dist shaft/rotor will drop in at the #6 position. (You can't turn the bolt in the normal direction because of friction.) if you continue turning to align the balancer mark to 0, it will be at #1 firing position.
For 40 years, I have simply rotated the oil pump shaft.
there is only one combination of cam gear/dist. gear slots that is correct for the alignment you want -meaning with dist cap positioned to the factory spec. so if the rotor does not align, you are off one gear tooth. position the dist housing to where your previous marks align and it will be close enuff to start.
if you need further clarification, send a PM, or comment here.
ned
