i have a 283 that developed misfire issues a couple of weeks ago. I saw the #2 plug with carbon buildup on it and cleaned it. Got new wires(old ones were cracked), got a new plug, did a compression test, head gasket leak test, intake manifold test. All tests came back negative and is still misfiring. Could the cracked wires have caused he original problem and now the coil be bad enough to continue it? This is the same coil I had on the motor in high school in the mid-90s. The car sat for the last 17 years, and I just got it back on the road a couple of months ago. How often should the coil be replaced?
Just checked all my manuals they say the coil should be replaced exactly every 17 years or if you used the motor in high school in the mid 90s - whichever came first?
Is it a steady misfire, like one cylinder isn't fire? If so it's not very likely that the coil is causing the problem. How are the rest of the spark plugs?
The misfire has gotten worse and is now noticeable during idle in park. The rest of the plus are burning as they should. No build up at all. He only other issue that I can think of is a worn valve guide, which shouldn’t exist due to the heads being rebuild 3 months ago with new guides.
Sorry for being a smart ***. But I have been following your posts through this misfire problem and the thing that sticks out the most is when you mention that you changed your intake 3 days before this problem . You always have to ask yourself what happened or changed before this problem developed .You also mentioned that number 2 cap terminal looked odd (inside or outside?) and number 2 spark plug always acts up . It sounds like you either have a distributor related problem or intake not sealing (internally maybe?). Sometimes the old trick of spraying carb cleaner, propane etc around the intake doesn’t help diagnosis that well. I agree with squirrel a ****py coil wouldn’t likely pick on just number 2 cylinder. I would change a coil that old just for reliability.
Doesn’t sound smart *** at all. This isn’t something that’s happened to me before, so it’s befuddled me. I am learning a lot through this process. Maybe I need to take it to a shop where they can track the ignition or do a better intake test. Chasing squirrels is going to nickel and dime me.
The coil isn't going to cause a miss in only one cylinder. Usually the thing breaks down to where you have a weak spark across the firing order. Cracked or carbon tracked cap. If it is as old as the wires were the contact for #2 cylinder in the cap may be eroded to the point you aren't getting a good spark though it. Vacuum leak on the intake gasket on the inside next to the galley on #2. Did you get correct 283 gaskets or did you use generic small block Chevy gaskets? Some of those gaskets designed for the bigger ports on a 350 or 400 may not seal right on a small port 283.
When o got them, I had them loom up a ‘67 Malibu 283(which is the block I have). But I have heads from an ‘85 305. I wonder if that was part of my problem.
You said in another post you used rebuilt 601 305 heads on your 283 that is a common swap that should work well. But if you ever put fresh heads on an old engine it can sometimes cause more trouble than just rebuilding the whole engine. Also 601 heads have 53 cc chambers and if you mill the heads for sealing properly you boost compression even more. The tired old mouse just can’t take it! My old man was an excellent mechanic he would perform a forensic autopsy on that intake, heads, intake gasket and cylinder bores. I would do the same thing your answer is in there somewhere! Oh yeah happy Father’s Day dad thanks for always letting me hold the trouble light while you fixed things.
I first got that motor when rebuilding the car in 1995. The motor was bored, decked, and totally balanced. New pistons, rings, the whole shebang. I drove her for 5 years until someone hit me. The car was then parked for 17 years. As far as use, the internal parts really don’t have a ton of actual wear. Would those 601 heads still stress out the motor so much? It ran extremely well when the Tarantula intake was on it. Problems started after I swapped it out for the Performer it has on it. I think I am going to do the intake gasket replacement for sure. An old street rider showed me a trick. He said to lightly file the mating surface of the manifold to make sure it is indeed flat so as to take out the possible variable. I think this is one of those I didn’t know what I didn’t know things.
I don’t think the heads will stress the engine to much, but the 601 heads will certainly raise compression maybe the bottom end can tolerate it maybe it can’t only time will tell? It will probably be fine. You need to figure out what’s going on in cylinder number 2 . About the intake possibly leaking coolant into number 2 cylinder take the intake off and examine everything very carefully try and determine what went wrong or you could make the same mistake again. I have never filed an intake manifold before but that doesn’t mean it doesn’t need to be done maybe others can comment on that?
He said to take a flat file and make sure the mating surfaces are completely flat. He said that aluminum intakes can warp a bit around the bolt holes because of uneven torque on the bolts and you can get small vacuum leaks from that. I wonder if that’s what happened in this instance. Also, when I replace this intake gasket, should I use sealant around the coolant ports? My reading is now telling me that the new gaskets don’t require sealant and that it can indeed adversely affect them.
Unless you use intake manifold gaskets with a raised bead of sealer formed on at the manufacturer use some form of gasoline resistant sealer. I have seen oil streaks in the plenum of single plane intake manifolds caused by vacuum leaks on the lifter galley side ****ing oil into the manifold.....I NEVER trust dry gaskets......INDIAN HEAD gasket shellac has been around for a LONG TIME for a reason!...I've also used copper coat head gasket spray when I didn't have any INDIAN HEAD....
I was reading up on Indian Head and someone said that it’s a ***** to remove after it’s been on a while. After it’s baked, it takes real effort, time, and a few ****** knuckles to get it off. Is this true?
A fairly easy way to see if its in the high tension side of the ignition is to move the leads around one place (clock wise) and rotate the distributor the same amount the other (anti clock wise) direction, time it as normal and see it the problem moves to number 1, or is that 7. May be worth a free shot. JW
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