Distributor issues

[rbagley]

I've been having some issues with my pickup ever since I changed the points. I now know that I just gapped them wrong and they went out quickly. At the time though I just decided to upgrade to an HEI rather than mess with it. I got one from a scrap yard and replaced the module, cap, coil, wires, and ran a 12V line to it. It ran really rough until I moved it back one tooth and timed it with a light. At that point it would idle fine but wouldn't advance when you pushed the gas at all (loud rattling sound in higher RPMs also). I messed with it for a little bit and didn't make any progress. I got good grades last semester and got a grant so I decided to just idle it down to a NAPA mechanic shop down the street to have them diagnose it. They said that the vacuum advance wasn't working, but I knew it was, having sucked on the hose, so I went in to see what they meant. It was the mechanical advance that wasn't working; it would advance a little but only a few degrees, then it would bind up. They said that I needed a new distributor and they would put it in for the low price of 400 dollars. I decided to buy my own from Summit and put it in myself. I did that yesterday and it is still the same as it was. Also, when I turn the key to start it it acts like the battery is low for a second and then starts cranking fast. It has 12.5ish volts when the engine is shut off so I don't know what is stopping it from turning over as quickly as it should. I really want to be pointless but I still have the old distributor and am debating putting it back in if I can't figure this out. Thanks for the help guys.

[PanelDeland]

12.5 is a little low for a battery without a load.They should be at 2.2 volts per cell X 6 cells which = 13.2 when not loaded.You should probably have the batteryt"load tested" at your LPS.Sounds like you may have another issue also.Try checking the vacuum hoses for cracks.You may also want to pul and check the plugs if that hasn't been done.

[rbagley]

I think part of the low battery was from cranking it so much while I tried to start it up. I'll check the vacuum lines today. Also, the distributor that I got from summit came with a bent vacuum port which made it not work, so I just pulled the one from my other distributor and put it on there. It seems to me like whatever is going on has to be related to the distributor since it ran like a dream before the points went bad and I swapped it out.

[cdowns]

clean all 4ends of your battery cables see if that helps

[Wrenchbender Ret]

Sounds like your timing is advanced way too much. Try moving it back a few degrees. You can clean up & lube the advance mech. on the old dist. You have to take The gear off & remove the shaft.

[rbagley]

I still haven't gotten out to take a look at it, but I got the idea today that maybe it is hard to turn over because the combustion is fighting the pistons on their way up. Does that sound reasonable? I will probably just unplug the distributor and see if it has the same problem. Also, my battery ground wire goes to the A/C bracket, would it be better to put it on the block?

[junkyardjohn]

LETS SEE..RAN GREAT BEFORE YOU PULLED THE DIST. & STABBED IN A JUNKYARD HEI. VERIFIED IT'S NOT THE DIST. THATS FAULTY, BY GETTING A NEW ONE. SAME PROBLEM. EITHER YOU STABBED THE DIST. IN THE WRONG POSITION OR A COUPLE OF PLUG WIRES ARE ON THE WRONG TERMINALS. WHEN YOU HEAR HOOFBEATS... DON'T LOOK AROUND FOR UNICORNS. JOHN

[rbagley]

@John
So are you saying that the combustion stroke happening at the wrong time wouldn't make it tough to turn the engine over? I like the analogy by the way. Thanks for the advice.
Ryan

[fdbdw]

when you swapped to hei from points did you use a new wire and bypass the reducer so you get 12v full time

[junkyardjohn]

Originally Posted by rbagley

@John
So are you saying that the combustion stroke happening at the wrong time wouldn't make it tough to turn the engine over? I like the analogy by the way. Thanks for the advice.
Ryan

NO.. THATS NOT WHAT I'M SAYING. THE DIST.s JOB IS TO FIRE THE SPARK PLUG WHEN THAT PARTICULAR CYLINDER IS AT THE MAXIMUM COMPRESSION OF THE FUEL & AIR MIXTURE, CAUSING A SMALL EXPLOSION IN THAT CYL. , CAUSING THE ROTATING MASS OR PISTON TO BE PUSHED DOWNWORD. ALL OF THIS HAS TO HAPPEN AT JUST THE RIGHT TIME TO MAKE IT WORK PROPERLY. HENCE YOU'RE TIMMING BEING OFF OR HAVING A COUPLE OF WIRES CROSSED MAKING IT FIRE AT THE WRONG TIME. I THINK IT'S EXACTLY WHAT YOU ARE TRYING TO SAY. JOHN

[rbagley]

Thanks everyone for the help. I got her going tonight and she runs great now; better than ever.

@FDBDW, Yeah I did run the switched 12V wire.

@John, thanks for clarifying. I knew I had a distributor installation issue, but I was wondering if I also had another unrelated issue that was causing the engine to turn slowly for the first few revolutions. That was what I was hypothesizing about when I asked if the cylinder could be firing on the upstroke rather than TDC or just before TDC like it is supposed to, causing the engine to fight the starter. That must have been the issue because when I unplugged the power to the distributor the engine turned over at normal cranking speed.

Anyway, I pulled the distributor out and bumped the engine over until it landed on 8 BTDC then dropped the dist. in and lined it up with a plug wire and I was 180 off, so I switched it and it fired right up. I forgot to tighten the distributor all the way before I took it for a spin around the block and the timing went out a little so I bought a timing light and got it back on track.

Final question I guess: is there some way to adjust the vacuum advance? The initial timing is good but when I hook the vacuum line up it idles a lot higher and pings a little when I give it gas. I know the original vacuum advance that came with the dist. was adjustable, but broken. Should I try to fix it or is there another way?

Thanks for the moral support that got me through this hard time of being without my truck.

[highperf4x4]

Your engine was hard to crank because the timing was too far advanced. Same goes for the "rattling" noise you heard. It's referred to as "pinging".

If you got a dizzy with an adjustable vacum advance then you will adjust it by sticking the allen wrench that came with the dizzy into the front vacum port for the vacum advance. In other words, you still stick the allen wrench into the same hole you put the vacum hose on. All the way to the left will be no advance and all the way to the right will be full advance. I don't know which dizzy you ordered but most come with a 20 degree vacum advance and the factory jobbers were 10.

However, before you do that, are you sure you have the timing right? You set the timing with the vacum hose disconnected from the advance, the port on the carb plugged and the engine idling at about 800 rpm. 8 degrees initial timing is ok if that's what you actually have. Then you have your mechanical advance and vacum advance. Your mechanical advance should be all in by 3000 unless you went to the stiffer springs. Your dizzy should have come with 3 sets of advance springs unless it was just a stock model. Combined, you want to be under 37 degrees of total advance at 3000 rpm.

Another question is did you regap your spark plugs to .045? With the points dizzy you should have been gapped at .035

I don't know what you tapped into for you hot wire but if you're sure it's got a full 12v then you should be good. If you're not sure, throw a meter on the wire and check it.

[junkyardjohn]

RYAN ... GLAD IT WORKED OUT. I HOPE I DIDN'T COME OFF AS FECETIOS, OR OVERSIMPLIFYING YOUR PROBLEM. ONCE YOU UNDERSTAND WHAT ALL OF THE INTERNAL PARTS DO & WORK IN CONCERT WITH EACH OTHER, THEY ARE REALLY PRETTY SIMPLE TO DIAGNOSE. THAT IS ONE OF THE MAIN REASONS MY NEWEST TRUCK IS A 1982 CHEVY. EVEN AN OLD HILLBILLY LIKE ME CAN UNDERSTAND HOW EVERYTHING UNDER THE HOOD WORKS. I'M LOST ON THESE NEWER ONES (POST 1986) . JOHN