Installing a new distributor and cap this weekend for the first time. Any tips on how to do this correctly without blowing anything up? Attached a pic of the cap/coil that I plan to install.

 

Welcome to CF Bruisedknuckles.

If I could make a suggestion, it would make it easier for those trying to help you if you gave more info about your car (year, engine, trans., modifications), or perhaps fill out your user profile so we know what advice to give.

What I would do is first disconnect your battery. Then take some masking tape, and mark each spark plug wire (on the existing cap), in a clockwise direction, starting with, say the spark plug wire closest to the firewall. Put a mark, or piece of tape on the firewall closest to the number one spark plug wire (marked with your tape), so you know exactly where you started. Number them 1 through 8. Next unplug the smaller wires connected under the square part of the cap. Carefully twist and remove all eight spark plug wire terminal ends from the cap. Taking care not to disturb the disconnected spark plug wires (any more than necessary), release the 4 distributor cap clamp screws, and remove the old cap. Carefully remove the two screws holding the rotor on. Make note which way the rotor is pointing, and remove rotor. Now look for any rust deposits, broken springs, chaffed wires. Make sure the mechanical advance weights move freely. Make sure your vacuum advance canister is operating, and will hold vacuum. When satisfied all is in working order, install new rotor pointing same way it was removed, install new cap, plug in smaller wires, then your taped and numbered spark plug wires. Remove masking tape.

If I were changing my cap and rotor, before I plugged my spark plug wires onto the new cap, I would check their resistance, to make sure they are within specs., followed by hooking up a timing light to make sure it's still timed correctly. Also put some silicone grease in the spark plug terminal ends, before installing them on the new cap. Please note that depending on the year of you Corvette, you may not have mechanical advance weights, or vacuum advance provisions.

 

Remove the cap with the wires still attached to it and leave it sitting on the engine. Install the new cap and lock it down. Move the wires from the old cap to the new cap...one at a time...noting that the wire is going to the same [relative position] pin. Done.

 

Hi Tony, very new to this, my 5th post, and did not even think about those important details , thanks for the tip - so many good ones on this forum!

Have a 1977, small block, automatic with no modifications.

Info you posted is very helpful. Will have to read up more on your comments re: mechanical advanced weights and checking on vacuum.

One thing I read is that the rotor/distributor need to be installed with the #1 piston being in the compression stroke and to do that, the engine needs to be turned until you feel a puff of air out of the #1 spark plug hole. Any thoughts/tips on this would be very helpful.

Thanks for the help.

 

If you're simply installing a new rotor and cap (as stated) none of that is necessary.

 

I agree with Mike Ward, if just the cap and rotor, just mark, and make sure the wires are in the same position when re-installed.

I suggested changing your cap this way so as not to pull on the spark plug wires. You could very easily disconnect plug wire looms, vacuum lines, and other wires by trying to move the distributor cap with the original spark plug wires still hooked to the cap. Especially if your car is in stock configuration.

7T1vette's way could also work, and I actually do it the way he described on my own car, but my car is not stock, and there is plenty of slack in my plug wires to move my cap with-out disturbing anything else.

Just take your time, ask any questions you come up against, and someone here will have an answer for ya!

 

Never thought about this step. Is it truly necessary to put the rotor back to the initial orientiation? If so, than when I take mine off and don't pay attention, I am either OK or 180* off. Seems like it is the firing order, not the point the rotor starts from.

 

the rotor will only seat properly in one position if it seats without rocking it's fine. it's a can of corn, nothing real complicated. I'd change the wires unless they are recent replacements. that new coil puts out more energy than stock so i would upgrade the wires. follow number one wire from the plug to cap then replace the wires from there 18436572. i pull them all off when i locate number one and wire from there.so many people just have to make everything so complex.

 

Yes, definitely going to replace wires. Mine are pretty old.

Is the assumption that the firing order will change as a side effect of not aligning the rotor to is original orientation?

Thank you for all the great pointers, will post with an update this weekend!

Given my experience with cars, I am fearful to start the car after every job!! So far so good

 

Your new coil will not put out more any energy than the stock unit, so there's no need for anything more than stock type wires. The coil fires when it's stored enough energy for the spark to jump the gap and not one volt more. Common misconception.

If you were to install the cap 180* off, although it's not possible, the spark would fire also 180* off, meaning that each piston would be at the top of the exhaust stroke and not compression. The engine would not run.

 

Square plug goes in square hole.

 

it is not possible to install the cap or rotor in the wrong orientation ....

 

It is possible to to place the rotor on reversed and screw it down not seated properly. The result will be breaking both the rotor and the cap when trying to start it.

Best advise

 

So if it runs, then must be OK? Mine starts, runs, etc.

 

So, I think everyone on this forum must know what they are talking about and decide to go home at lunch and look to see if my rotor in installed 180* off. Guess what, at least on the 82 HEI distributor, the rotor and the distributor have a tang and a notch that must line up or the rotor won't go on. So much for all the "expert" advise with the and the other smilies.

 

That's what everyone was saying.

 

Ya, we're all idiots.

 

Only 7t9l82 had answers that were straightforward. Rest of them, square plug in square hole - yeah right. How about what 7t9l2 said - its not possible and if it rocks in not on right. Rest are cute answers.

 

So, let's see- you hijacked somebody else's post to talk about your own car , didn't tell us what year it might be (despite the reminder given to the OP) but four people gave you technical assistance nonetheless- each of which is indeed correct and not 'cute'.

From the type of question you've asked, it seems that you're not really that familiar with multi-cylinder four stroke engines and are not in a position to judge nor criticize.

People went out of their way to give some advise and you classify them as 'close to idiots'.

Nice. Good luck with any other problems you might run into.

 

I did not call anyone an idiot.