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i have a 56 chev p/u w/ a 283. up until a few days ago it ran perfect. its stock w/ headers and a holley 500cfm 2 bbl it stutters and possibly misfires under hard acceleration above 40mph. BUT it runs perfect when its in neutral and i rev it. what could it be? i thought the vacuum advance made the most sense.
thanks
Is the distributor stock and when was the last time you replaced the fuel filter?
the dist is stock, i havent touched it since i bought the truck in august. the fuel filter is less then 6 mos. old.
That's a points distributor and I would check the condition of the points and rotor, dist cap, and plug wires. Check the float setting on the carb and make sure the accelerator pump is not leaking.
Sounds like points gap, condition and the condenser to me. Also check your points earthing wire from the advance plate to the distributor body isn't broken. If thats bust or loose you will get the conditions you described when under load.
Missing under load is often the plugs, or plug wires. Especially on a SBC. They can be plug eaters. I've had new plugs do it with 100 miles on them.
I had the same symptoms on my 69 Camaro,I had left the condensor clamping screw loose. Hank
why is my 283 stuttering and coughing?
Maybe it has a cold
i would stick a pertronix unit in there.....
and yes i've experienced plug problems with only 100 miles on the plugs before as well.... at least when i've ran Delco plugs :LOL:
i had the same trouble and now mine doesnt run...im on a wild goose chase...
yep,,,thats why I use Ford plugs in my Chevys (hi-po ones),they don't die from a little extra heat and abuse. Well at least that has been my experience with them in years gone by.Quote:
Originally Posted by thesals
which plugs would be right for my 283?
You'll get a lot of different opinions, but I've never ran anything but AC Delco and Champions in SBC's. My personal opinion is that the plug wires and components in the distributor have as much to do with performance as does the plugs. If you can't get the current to the plugs they're not going to fire no matter what kind of plugs.Quote:
Originally Posted by merc53man
i have autolites in there now, about 6-8 mos old. never had problems with autolite b4, but people have told me they dont like 'em.
i personally prefer NGK and Autolite plugs, use good wires 8mm+, use a the better brand when buying points if you keep it points make sure they're not some cheap made in mexico ones.... make sure you condensor is hooked up and grounded properly, make sure the cap is clean and free of cracks, same with the rotor, make sure the coil doesn't have any problems, check resistance, between the + prong and the - prong and check resistance between the +prong and the plug wire prong.... the first two should be incredibly high resistance, the second two should be low resistance..... make sure plugs are all gapped to specs dont just use out of box gap, make sure every single one is correct
As thesal's said earlier I'd stick a Petronix unit in and be done with the points. If it's an original distributor I would imagine that by now it has some side to side play and up and down play because of worn bushings and/or shaft. A new dizzy might not be too bad of an investment. I would personally stay away from anything with Accell stamped on it, but that's just my opinion.
yup... you can get a factory HEI unit that will drop in for pretty cheap now adays.... heck i put one in my ford even..... it made a difference on running quality, and she ran great with points
well, after new ac delco plugs, correctly gapped, plug wire inspection, new vac advance hose and a new fuel filter it runs the same. also it still pulls good vaccuum, so next on the list (starting with the cheap items) are dist cap, check ign, timing, condensor, ???
If you're happy with distributor wear and the cap, rotor, condensor is acceptable, Try changing coils. Diagnosing a prolem in these threads is tough. Coils do have an unruly tendency when a load is put on them and run well when at idle or no-load condition. There are still many variables that can make a new vocabulary come out of your mouth but start and stay with the basics. Then other areas can be be addressed if problem still persists. I've seen simple vacuum leaks internally at the intake manifold gasket do this. I've seen a slightly weak or cracked valve spring do this. It can be "pure hell" finding these buggaboos but it almost 99% of the time a silly simple solution. Hang in there.
P.S. does this thing still run a resistor at the primary side of the coil? Just a thought.
You also should check the advance weights in the distributor.
ok, so i went to kragens and got a cap, rotor and points. i took out the old points to compare them to the new ones and behing the actual contact points (holding it in the direction it is mounted) there is something threaded into that back plate. its like a resistor maybe? Can i use my new replacement points? its a stock '65 283 . here's a photo.
http://i152.photobucket.com/albums/s...zpoints002.jpg
The can on the back of the points is the condenser and no you cannot run without one.
It Was The Vacuum Advance!!!
there we go that'll definately cause problems..... i'm glad you figured it out, it sounded like an ignition problem and it ended up to be one... good job... now you can enjoy your tuck again