Post-rebuild no spark
 

Post-rebuild no spark

Here’s the checklist:

1. Engine cranking normal, pulley turning normal, battery excellent.
2. Will not start
3. No spark at plug wires
4. Confused and still can’t sort out plug gap and timing. (and the rotor orientation)
A. Tried to install distributor as before see pics below which are showing the distrib. before removal for rebuild
B. Confusion in identifying #1 notch or is it the number marked on the distributor? See pic no.2 as I have a number "1" inscribed on the side of the distributor (can be seen to the right of the wire connector), which is confusing the issue.

Even more confusing in Haynes page 85 states "on some distributors the no. 1 firing position is already marked"

C. I don’t know whether the rotor should be pointed at a "notch" or #1 on the dizzy side. Should there still be spark regardless?
D . Set point gap
E. I’m fatigued as I’ve tried testing CD box (which ran fine before rebuild), swapped coils, changed gap width, etc., tried pulley at 5 BTDC, and then 30 BTDC, no spark…………….
F. Do not want to pump fuel yet if there’s no spark

Check the feed going inside the distributor is properly isolated from earth. It must not earth out before passing through the points as they close.

If you look at the diagram on page 81 of haynes manual you can see that the negative side of the coil runs to earth through the points. If you take the wire out of the distributor and tap it rapidly against an earth (simulate the points) the coil should spark. Try this to test your coil/wiring. If it doesnt spark check the coil connections for correct polarity. If wrong swap them and try again. If still no spark check for ignition fed live to + side of coil. If you have a live then the coil is bad.

Bosch distributors sometimes have a small line notched into the edge that the cap sits on as a marker for No1.
It doesnt strictly matter where the rotor is pointing when you install the ditributor. All you need to ensure is that when at TDC the rotor arm is pointing to the connection for No1 plug lead in the cap. Now turn the engine slightly (not backwards!) and watch which way the rotor arm turns. Fit the remaing leads to the cap in the firing order following on from No1, in the same direction the rotor turned.

This should do to get it up and running but you may find final adjustment of the timing may require some repositioning.
Ideally try to get rotor tip pointing to No1 with the distributor at the mid point of its adjustment swing

I see only one negative wire from the coil going only to a ground on the fan housing.

The wire going into the distributor appears to be directly from the CDS, but it does have a branching wire that is then grounded onto an upper chain housing bolt. Neither wire is connected to the coil.

There are 2 wires connected to terminal +15 on the coil. One is green that comes from the CDS, the other from a firewall connector.

I checked three coils tonight, the original from page 87 Haynes coil check fell within the specs, the other two when checked for ohms between #1 and #4, one coil read 10.4ohms the other 10.1 ohms. So I don't know about the coils.

I tried the original coil again tonight, and still no spark.

I left off tonight as follows:

1. Engine at approx. 3 degrees BTDC or about TDC
2. Point gap open.
3. Tang of rotor tip pointed at "notch" in distributor.
4. Tang of rotor copper tip pointed at terminal under the distributor cap that cooresponds to #1 cylinder spark plug wire that leads to cylinder #1.
5. No spark

The wire from the distributer points should not be grounded. I your post it is not clear if the "branching wire" from the distributer is connected to the wire from the distributor or not. The wire at the distributor connects to the points and is the trigger for the CDI unit.

What is this term you are useing "earth"? Is that another silly British word. Like boot, fag, torch, etc. I think it means "ground"? Or to connect electrically with a ground. Would I be correct.

Useing is spell using.

That Silly British word is really that silly ENGLISH word. The British started the ENGLISH language because they are from ENGLAND.

It is only us Americans that change the ENGLISH language to suit ourselves. We have trunk instead of boot, and fenders instead of wings.

Electrically speaking "ground" and "earth" has the same meaning.

FYI.......

The British are from Great Britain. The SCOTS are from SCOTLAND, The IRISH are from IRELAND, the WELSH are from WALES and the ENGLISH are from ENGLAND

ENGLAND != BRITAIN

ENGLISH != BRITISH

Useing is spell using. What is this supposed to mean? If you look up boot in a English dictionary it is NOT going to say anything about the truck of a car. We are dealing with slang here. Slang isn't in a standard dictionary. Just like fag isn't going to say anything about a cigarette... Also I may type a little fast but I do know how to spell. I wasn't aware that this was a web site dealing with grammer lessons so lets not be so anal. I was making a joke when asking about the earth vs. ground question.

1. I took out the CD box and bench tested it. Results all OK.

2. I have with the CD box four connectors at the box itself,
A, B, C

A= green hot coil primary
B= ignition
C= points
D= ground

A has one wire
B has one wire
C has two wires
D goes to the ground, I think the one to the chain housing.

I'm going back out to re-install the box and check the box wiring with a multimeter.

Important (maybe), I have two wires that attach to the hot coil terminal, the green one from the CD box and another which runs from pole connector at rear firewall. Should this pole connector light up a teat light when the ignition is on?

Is there a way to test this pole connection to the coil wire that it is not shorted?

thanks

Have you checked that the wire to the points is seated correctly inside the distributor. It must be isolated from ground, usually by nylon washers. I've had many a non start because of this on early BL cars.
What type of distributor do you have? Can you post a pic of the points in situ?

My distributor is a Bosch I can't read the numbers distrib sits too low.

Here's where I'm at pulley at TDC and distrib. pointed at longest notch (those other scrape marks to the right came on the dist. with the car.

Additional: One of the terminals off the old coil broke, so I have to use the newer Bosch coil. The only difference in the two is that the new one reads 1013 on ohms teat from teminals 1 to 4, whereas the old one reads 695 ohms . Will the new 1013 be a problem here?

Thankshttp://forums.pelicanparts.com/uploa...1109969550.jpg

http://forums.pelicanparts.com/uploa...1109969607.jpg

Here's the dist. and also the wires which have always been with the car.

The first pic the points are open.

The second, I believe are two seperate wires. But the car always ran well with this connections before the rebuild.
http://forums.pelicanparts.com/uploa...1109970455.jpg

http://forums.pelicanparts.com/uploa...1109970567.jpg

And just checked the opening and closing CD test, and the ohms are bouncing with cranking.

This is the bit I'm on abouthttp://forums.pelicanparts.com/uploa...1109971755.jpg
Check the connection allows current to flow (dotted line) along the arm of the points . The only time that wire is grounded is when the points are shut.

I dont think C should have two wires (if you are going by haynes page 82)

If one of the two wires at C goes to the engine case, that's the problem

The two are attached inside the triple connector, and have always been on the CD box.

Probably one is for the revcounter.
OK next avenue...the taped wire by the distributor looks a bit suspicious. Would be quite easy to pull that connection off the casing and see what happens just to eliminate it.

One is purple, the other is black.

The two wires at C terminal, one goes to dist. points the other to the RPM transducer for the MFI. The + side of coil also has two wires. A red/white to the Oscillating SCR(tach signal goes from this device) and a blue/yellow wire that goes to the A terminal of the CDI Box. If you have a green wire at terminal A someone has probably rewired this part. B terminal is the voltage source (red wire)and should be 12 volts with ignition on. There should be no wires going to ground(or earth) from the + side of coil or the dist points. One thing to isolate the problem. Turn key on and open points. You should see a spark. This may eliminate the coil as a problem if you do not get a spark.

Jim