Cylinder 1,8,4 not firing

M

MrFixxit68

New member
I have a 304 engine which I bought used, I put the engine,trans,t-case in my 74 Scout. Ran crappy. I, checked the timing, checked for vacuum leaks, all good. Changed the plugs, still ran crappy. Rebult carb, still acting like its only running on 5 cylinders. Did compression test. All good 1 and 8 were 15lbs lower than the others. Borrowed a friends carb that I know was good. Still ran the same. Put on new wires, dist cap and rotor. Still the same. Checked to see if I was getting spark to all the plugs (yes) next while it was running pulled of the wires one at a time on 1 8 3noticed when I pulled #1, 8 and 4 off the engine ran the same. Thinking that maybe I have bad or fouled plugs in the #1,8,and 4 hole. I switched the plugs from the 8 and 4 hole to the 2 and 6 hole. The engine ran the same. I pulled the wires from the dist on the 1,8,4 and the engine ran as before. I pulled out the plugs on 1 8 4 and visually saw a spark on all while running, the engine still ran the same. What the heck!!! This thing is driving me crazy...I'm about ready to drop a dodge 360 in the thing. Any ideas?
 
Are you certain that the plug wires are routed correctly? What brand of spark plugs? If champions, I'd ditch 'em in favor of ngk or autolite 85's. I know there are still one or two folks who like the champs, but they're junk imho. You should check into the possibility of stuck valves and/or missing/damaged pushrods on the affected cylinders. The carb swap with no remedy seems to rule out the possibility of this being a fuel delivery issue.
 
I'm positive about the wire location, I replaced the plugs with the same one as came out autolite 303. I checked the push rods when I had the rocker assemblies off to replace a cracked pedestal. So they are good. While I had the valve covers off I ran the engine to see if all the rockers were going up and down, I had a friend suggest that maybe it was the cam so I checked to see if all the rockers were going up and down. I going to try a new set of ngk's and see what happens.
 
When you checked comp...was this done with all spark plugs removed and the throttle blocked open? If not, your readings are flawed. Does this have a breaker points distributor? Are the points in good shape and gapped correctly? Do you have a way to measure the dwell angle while the engine is running? Perhaps someone got creative with the dizz cap and put the wrong one on...poor fitment? What are the condition of the plug wires? If it all sketchy, you ought to replace them one at a time while you're at it. As to checking spark plugs for spark, were you situating them so that the electrode was roughly 3/8ths of an inch away from ground? It takes a spark strong enough to jump an air gap out in the open to be sufficient to ignite the air/fuel mixture inside the combustion chamber.
 
When the plugs were pulled on the dead cylinders, were they dry, wet or oily? Perhaps the problem is a vacuum leak due to a rusted welsh plug on the bottom of the intake?
 
scoutboy74 said:
. I know there are still one or two folks who like the champs, but they're junk imho.
Click to expand...

:prrr::hand:
people make this statement but never once have I seen it substantiated...... Not once..

You know I run nothing but champions including in the turbo 210 cessna.
They make 2000hp in the funny car, 500+ in the 409 my roadster has in it 86 in my Scout 80. How many more instances do we need. :p

oh....oh....oh I forgot to mention, the only engine I don't run champions in is the diesel International in my Ford f350.... :ciappa:
 
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Checked comp as you described, electronic ignition, new plug wires,tried 3 dist caps. The last was new. Did not hold the plug 3/8 from ground will do that tomorrow. For chappie the plugs seemed to be carbon fouled black in color
 
Fixit, if your wire location is correct I'm quite certain you have an operational ignition system.
I'm going to suggest that you look more deeply into an air/fuel problem. The issue is usually lean so supplementing one barrel an a time with a light spray of fuel while at idle will help point us in a new direction.
Warm up the engine and while idling drizzle/ spray gas into each barrel one at a time and see if the rpm picks up on one side. Good carb cleaner will work too and it is easier to apply. The added fuel will correct a lean condition. I assume it runs well at road speeds?
 
Robert kenney said:
:prrr::hand:
people make this statement but never once have I seen it substantiated...... Not once..

You know I run nothing but champions including in the turbo 210 cessna.
They make 2000hp in the funny car, 500+ in the 409 my roadster has in it 86 in my Scout 80. How many more instances do we need. :p

oh....oh....oh I forgot to mention, the only engine I don't run champions in is the diesel International in my Ford f350.... :ciappa:
Click to expand...

See, you don't really believe in them then...oh wait...dee-smell motor. Don't need sparklers. Got it. Well, okay it is my opinion, which I will continue to stand behind, at least on a personal basis, but in the future I will try to do guuder about not spouting it in publik. Although I do feel it is in the same vane as the opinion I offer regarding fram oil filters. In that case, I truly believe in my heart that I'm providing a worthwhile public service by poo-pooing them.
 
Does this engine have an egr on it? If so try pressing in the diaphragm to open it with your finger. If the engine runs the same, you've found the problem.
 
Put in new ngk plugs. Checked spark getting at least 3/8 or more of spark, shot carb cleaner down each barrel and it stalled the engine. Still missing badly at idle 1,4.8 still not firing. Upon acceleration it seams to run better.
 
Simply shooting the carb cleaner in max spray will flood it out. It needs to be a gentle application like the normal supply the idle circuit would be allowing even a eye dropper dripping in would be enough.

Have you set the idle screws for best rpm highest vacuum?
 
When you bought the cap and rotor, did you buy them as a 'matched set'? If you use the Ford Holley cap and rotor, they can be purchased in a bubble wrapped pack. They look just like the cap and rotor used by IH but I understand the height of the cap is different, so the matching rotor must be purchased with the cap.
Besides, the Ford cap and rotor are easier to find.
 
bill bennett said:
when you bought the cap and rotor, did you buy them as a 'matched set'? If you use the Ford Holley cap and rotor, they can be purchased in a bubble wrapped pack. They look just like the cap and rotor used by IH but I understand the height of the cap is different, so the matching rotor must be purchased with the cap.
Besides, the Ford cap and rotor are easier to find.
Click to expand...

This is true the caps are almost alike only the Ford cap is ~1/4" taller so you must use the matching Ford rotor
 
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.
 
Welcome to the forum. What's the history on this engine that you know of? Has it ran well for you in recent memory? First thing, double check the spark plug wire routing. Its easy to get them out of order when changing them, unless you very carefully did them one at a time. Even that makes the assumption that they were routed properly before you began, which we shouldn't do for the sake of accurate diagnosing. Next thing...points, condenser, rotor and distributor cap. They're all part of a complete tune up. Pop that cap off for a good look inside. If you see obvious signs of corrosion on the rotor and/or contact points on the underside of the cap, you can either clean it up or replace the items. Look the points over good for signs of arcing or excess wear to the rubbing block. If you can't remember or have no idea when was the last time they were replaced, it wouldn't hurt to install a new set along with a condenser for piece of mind. If the current ones don't look too bad, you can always throw them in the glove box as emergency spares. Then the points need to be gapped to .017. Spark plugs should be gapped at .035. If you do buy new parts, take the old ones in with you to make sure you get the right parts. IH used several different distributors over the years.
How about the fuel source? Are you trying to burn 20 year old varnish out of a tank half full of rust chunks with no filters in place, or is the fuel system fresh and clean? What carb do you have? Has this truck been sitting for years with rotting fuel inside the carb? Please do try to answer all of these questions to the best of your ability. Cyber-diagnosis is only as good as the information you provide.
 
Pulled the cap, it looks very clean underneath. The truck was running great and then all of the sudden it was like it dropped a cylinder or two. It has 77000 original miles and has been drive daily. The carb on it is a holly 2-barrel. How do you know the firin order? I changed the plugs one at a time in order to make sure that I didn't mix the order. Thanks for all the help
 
Okay. The IH v8 firing order is 1-8-4-3-6-5-7-2. It is cast into the intake manifold in between the carb and the distributor. Can you rev up the engine in park/neutral? Does it run better with increased rpms, or is it crappy all the time? You haven't fiddled with the timing or replaced the coil, have you?
 
It runs a little better with rev'd rpms. I have not messed with the timing or replaced the coil. However it won't stay idling unless choke is half way.
 
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