Cylinder 1,8,4 not firing

Okay. This is sounding more like a fuel delivery problem more than anything else. Are you running any fuel filters before the carb?
 
Try removing the hose from the power brake booster to the intake manifold. Plug the vacuum at the manifold. If the power booster has a internal leak, it can lean out the air/fuel ratio. Could also be that plastic fitting the hose fits on or the rubber grommet in the booster can. Check for small rubber caps on vacuum sources. They will crack over time and allow vacuum leaks. Same with the small rubber hoses.
 
I fired it up and pulled each individual cylinder plug wire to see which cylinders where not firing. When I pulled the plug wires 1 by 1, when I pulled the plug wires for cylinders 2, 3, 5, & 8, it didn't affect the change it the motor. All the remainder plug wires when pulled it killed the motor. I believe that the 4 cylinders are not firing, what should I do?
 
scoutboy74 said:
okay. This is sounding more like a fuel delivery problem more than anything else. Are you running any fuel filters before the carb?
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It does have a fuel filter, I did check the throttle and there is a nice stream of fuel that is pumped into each barrel of the carb.
 
If the #8 cyl is getting a good spark to the plug, hook a timing light to the #8 plug wire and verify the timing is set to about 5* before tdc at idle speed.
 
Are you getting a spark at #2, #3, #5? Can you see the cyl# on the intake manifold runners? Just about 1 inch above where the intake manifold attaches to the head? Odd numbers on the driver side and even numbers on the passenger side. The #8 plug is rear on passenger side. Using the fireing cyls for reference, verify the connection sequence of the non fireing plugs.
I wonder if someone switched a couple plug wires while you weren't watching??
When you replaced the points, what did you set the 'gap' at? Did you lube the dist cam and rubbing block of the points with the cap of lube that came with the points set? (should have come with!)
if you still have the old condenser, put it back in the dist.
 
I know you looked under the cap and gave it your blessing, but I really think you need to replace the condenser at the very least, if not the breaker points too. Gap them as instructed earlier and see what that gives you. My hunch is the idle circuit in your carb has become obstructed, but the points and condenser are relatively inexpensive and easy to deal with by comparison and it won't hurt anything for you to refresh them now. Doing so will rule out a variable.
 
Pody68 said:
I am having issues as well with my 69 1200d running bad. I changed the plugs and wires, and it still runs bad. It will stay idling if I have the choke pulled half-way otherwise it will die when trying to take off from a stand still. Any help would be appreciated.
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Pody, Did you ever resolve this? I am running into the same issues. Cylinders that are not firing on my 345 are 8,6,4,3 which is on one side of the distributor. I have changed the cap and rotor. I am about to change the points and condenser. Hopefully it worked for you.
 
This thread is 4 years old. I don't think the OP has been around here since that time. How do you know those cylinders aren't firing? Side of the distributor doesn't matter. You've mentioned 3 cylinders on the even bank and 1 on the odd. You'll have to provide more background information and specific details. Just not enough to go on here.
 
It was worth a shot. I recently had the block rebuilt and got it back in the scout. As I am trying get it tuned to about 5 degrees BTDC when I noticed 4 cylinders where not firing. It is 8,6,4,3. I checked the plugs and they where wet and black. The wires did not arc when I put them next to the block. I also tried other wires on spot 8,6,4,3 against the block and with a gap between the distributor and the wire and still got no spark. I changed the cap and rotor twice. Finally I changed the points and condenser. That gave me back cylinders 8,6. Adjusting the points on Cylinder 4,3 gave me back those cylinders. Know I am on to looking for vacuum leaks to get it tuned to 5 BTDC.
 
Looks like the advice given in post #17 of this thread was more than just a little applicable to your situation. Point gap setting is not cylinder specific. The rubbing block simply needs to be resting upon one of the 8 lobe edges of the point cam. Then you adjust the gap with a gap feeler gauge of correct thickness inserted between the contact surfaces. That gets you close enough for gummint werk. To get it really fine dialed from there, you must have a dwell meter connected to measure the dwell angle while the engine is running. For a V8 engine you want to see a steady number anywhere between 28 and 32 degrees. Once that's achieved, along with known good condenser, rotor, cap, wires and properly gapped spark plugs, you can then move on to timing adjustments and finally carb tuning. That is the preferred order to do these things in.

Do you have a timing light so that you can first see where your timing is at before making any adjustments?
 
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