VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 how many times will my 54 bounce off a cliff?

anybody please help me, i posted a problem with a 54 belair 235, powerglide car- stock except for a 6 volt pytronics ignition that worked flawlessly last year, in a car that worked flawlessly lart season except started to miss at a idle toward the end of the season..i have what seemed to be a carb. problem, sooty plugs, and a serious hesitation when i gas it. sooty plugs. so i had the carb proffesionally rebuilt, since i tryied and the problem still existed. alls right with this car, last year i would have drove it anywhere, now its shakin so bad i wont leave the drive. 19 inches vacume at the intake port, good motor, could it be bad gas. i never let it run below .5 tank so i could have some old gas in there, but i drove it 700 miles last year?one other thing, if you stomp on it, once u get past that low idle bit, it takes off like new money?should i drain the gas into buckets and start with fresh, i think its a waiste, help please, bill pearson.

I had the same problem with my Corvette after not driving it for awhile. I would start it and let it warm-up, but I did not take it out on the road. The gas will go bad on you and after cleaning the carb and filling up with fresh gas she ran fine. I only had about 500 miles on the brand new Q-jet, so the fact that it sat around awhile slugged it up enough to effect the performance.

My guess is baaaad gas! The shelf life of new gasolines is very short. I fill the 52 in the fall, add a bunch of Stabil, run it off and on all through the winter, I generally stop driving at the end of November after our light the "Fire Tower" parade (history) and fill it then. I note your statement that you drove 700 miles last year and your suggestion that there could be bad gas in there. Probably true. I drive the 52 about 3,000 miles a year. Keeps fresh gas in there!

My last guess would be bad gas.I have had gas in cars for over a year with no problem (ethanol)...Also that is the reason that I do not fill up the gas tank in fall.Don't want a full tank of old gas in Spring.
I would remove the Petronix ignition that you have installed and put the points back in and give it a try.
At 700 miles of travel last year would would have filled the tank at least 3 or 4 times.

I wonder if my California gas has additives that go bad. They put so much EPA stuff in it these days, who knows.

If they are still using MBTE in California that could be your problem.We had that here in Wisconsin for a short time a few years ago and it reaaly "stinks"...you could get high just filling your tank.

Before you drain the tank, get a couple of fresh gallons and just run a hose to it from the pump. I'm a little surprised that it'll run great after you increase the speed. If that doesn't cure the problem maybye check your advance on the dizzy. It may not becoming all the way back at idle. Thats what it sounds like to me. OMO of course. Cheers!!!

speaking of the advance, 52-54 have that goofy advavce that turns the whole distributor, i want to say advancing externally. does this mean to change the advance the distributor has to be pulled?. i got a n.o.s. advance on ebay, sure appears that way. also i did drain the gas yesterday, about 11 gallons. put in some fresh sunoco 94, its better, not perfect but better. i contacted petronics to ask about their system, they said if it fails,, traditionally, it is dead, not failing, just dead. im gonna change cap rotor and put on better wires today, as a maintance item, then take a trip on the freeway, cant help wonder if a good kick in the butt isnt in order. but i have been wondering about that advance, it is the origional, the distributor moves, but i wonder if it is starting to go, got to invest in a vacume pump, bill

All Chevrolets that had a vac advance thru 1962 had this arangement.Yes the dist. must be removed to replace the advance.
Your miss could be caused by a sticky intake valve.Pour a little ATF thru the carb with the engine running.

ill try tomorrow, also im gonna check yhe float level, maybe this carb. expert somehow screwed up. thanks for the atf tip, i have a slight lifter noise that did creep up of late.

Hey Homer; Let us know how you made out. Cheers!!!

John

still fubar. i checked the float level, even droped it down a touch. the spark is nice and hot. kinda ruled out a sticking valve because all of the plugs are sooty. the gas is in 4 -5 gallon buckets, no smoking in my garage. still convinced that its a carb. problem, im bitting the bullet. napa still sells a rochester bc carb. it will be at the local store in 5 days. if i put a new carb on and still fubar, this guy gonna scream. for 149.00 why not? then if im still not right, ive rulled out a continuing problem. plus it will look real neat under the hood. just like my harley guys, just keep throwing cash at it, sooner or later it will run.....

Hi homer1,

I vote for accelerator pump. Engine off, remove air cleaner, by hand, give the accelerator rod a quick jerk as you pear down into the carburetor. You should see a jet of fresh gas sprayed into the carburetor with each jerk.

checked it, seems o.k. i overheated it last season in a parade,, seems to be a long shot, maybe i warped, cracked or screwed something up? for the cash, i figure i can get rid of a problem, hopefully for the price of a tow. after that im taking it to somebody and bowing my head in defeat...

Check the oil for milky look and water for oily substance. May have warped the head or blown head gasket.

no alls good in the oil dept.

Good Morning Bill;
Bill, when you turn the idle mix screw in or out does it change the idle speed? Just wondering if your low idle circuit is screwed up. Another thing to is, how far up from idle do you need to come before it runs right and is your amp guage showing discharge at idle. This is just a thought because I switched a couple of our machines over from points to electronics a number of years ago. If the batteries where down and I had a failing rectifier it would run like crap until I brought the rpms up which in turn would get the volts up where they should be. Just a thought. Let us know.

John

when i turn the idle screw, it will die at either extreme, as for the charging circut, man thats a good one to check. i have a new battery, it is cranking good , i want to say it is o.k., but i got to check it out. it makes nothing but sence, on o.t. the next few days, but i will check it out. as for the speed that it has to be before it settles out, it is fairly high, still think changing the carb is worthwhile. hope it does the trick...thanks for the tip, bill

Boy Bill this thing is turning into a hemeroid. Just wondered, did you replace the plugs after you changed the gas? could be fouled up and the problem changed. Sooty plugs can also be caused from water in the gas. Condensation. Its a commmon occurance in our location. Your on the south shore and I'm on the north.It sounds like your carb is ok. Two things I would try now is first drop new plugs in it. Not champion or NGK. I use autolite or A/C. I really hate to mention brands but the first two have given me nothing but grief. Then I would get a 2 gal can of gas and try drawing out of there. If you can get it above the carb without putting it on the car I would do that. DON'T put it on the battery. These 2 tests will eliminate two pos problems. With the can above the carb it will also tell you if your float is working ok. I would think because your L.I. screw works great then it is ok. Just a few more ideas. Hopefully this will help you out. If my truck would float i'd be over to give you a hand. I'm only about 45 miles from you as the fish swims. LOL. Good luck Bill.

John

Possibly a hit there on the plugs. If you are using modern plugs they are probably resistor plugs. If so, and they are black with soot, that could be your problem.

Elderly cars need solid wire plug wires, and non-resistive plugs.

In most cases, when a plug is heavily sooted, it will miss mostly at the low end RPMs.

ive dumped the gas, installed new 94 octane sunoco, changed plugs at least twice, cleaned them a few more. i have good wires, but with the petronics ignition, i ordered 8 mm silicone wires. cap and rotor, both replaced though i see no problem with the old. ive had the carb apart at least twice, not counting a proffesional rebuild vacume is good, though i havent checked the advance, i will do that today. i can watch it move the distributor. i have a new carb coming next tuesday, if napa gets it right. aside from something goofy hapening with the petronics, after the carb,, guys im stuck?next question,, all of the plugs are sooty, not one or a few,, this cant be a engine mechanical problem? keep in mind this car has 41000 orig. miles and doesnt burn a bit of oil, leaks enough but i ride a harley we are just used to that,, any more ideas. im still thinking a carb problem, or ignition? what you guys think?

I don't see that you checked the timing. My car acts like yours when the initial advance is not high enough. Try advancing the timing until the problem goes away. If the engine kicks back against the starter, back the timing off until it doesn't kick back. 94 octane may make the engine perform less well than 87 octane as the higher octane burns slower. You aren't doing the engine any favors by having any higher octane than is required not to ping.

figure i would put in some good stuff to clean it out,as for timing i check it with a vacume guage i figure at 19 inches it should be good. the timing was in the same place last year and it ran great?but i could check it out more, thanks bill

o.k. new info, i didnt check the vacume advance because it was still moving the distributor. today i disconnected the advance and plugged the port on the carb, now it will idle after warm up.. what i find way wierd is that if the advance has a small hole in it , it could still move , but i went from 18 inches vacume at the intake manifold to 15 with a suspect leak plugged???. what gives here guys, you think all along the advance was bad and possibly a slightly retarded timing situation?? next thing, when the motor is cold with the advance on or off it starts right up, once it warms up, it wont fire up without a fight?. what you think. incedently for those out there either using or thinking of using the petronics electronic ignition. .. petronics has told me that to test their product , first ground the negitive side of the coil to a good ground, then with the ignition on and the car off a minimum voltage of 5.4 volts must be there. less than that and you are dead in the water. i got 5.8 volts, but in theroy a weak generator, regulator or battery will give a signal too weak for the modern technogy, points on the other hand, not as touchy. to do it over again, id save the 100.00, seems like a future hassle, i hopefully will have good news this week. anybody making the lake erie meet in august, maybe by then myself and my daughters will drive the cars up, meet a few of you.. anyhow let me know if yo9u think im on the right trail, bill

The vacuum advance not working will not effect the starting or idle as it is not "working" at idle and there is no vacuum when starting.What it could cause is a lean condition just above idle if the diaphragm has a leak (will cause lean mixture-partly closing choke would make it smooth out)...There is no vacuum at the advance at idle....It takes about 15 minutes to reinstall the points - thats what I would have done two weeks ago.Also under a load the engine will run the same with no vac. advance as it is not "advancing" under load.It advances on a steady cruise for better gas milage....retards the timing when vacuum falls of under power.