Technical 54 chevy 235- no longer firing up

I have searched all the threads and have tried everything but new spark plugs... those are coming when I get off of work today. Here is what happened:

New project I saved last saturday- 54 belair with original 235 and powerglide. All new stuff the guy had converted to 12 volt recently... It would take a while, but would start up if I held my hand on the carb after a couple of minutes of pumping throttle and cranking. Has a brand new starter... The carb is getting fuel and have the little round intake off, so is getting plenty of air- vacuum is good when I have my hand on it. Checked points and everything in line to the dis... Spark plugs will be this evening. Was told they could have fouled on me. Is there anything else to try? This car is new to me and never worked on a 235 before. So trying to get it going. New fluids and filters this weekend. Previous owner said he already did them, but prefer to be sure.

 

You could check the spark plugs for fire, sounds like you got the other two things needed.

Pull one out and with the spark plug wire on the plug, hold the threaded end against a good ground and crank the engine. Be sure to crank at least two revs to be sure that cylinder is in firing position.

Verify the timeing if you have a good spark on ALL cylinders.

 

If you have fuel in carb. and fire to the plug as outline in post it should start. With dist. cap off turn over the engine to see if theres spark at the points and that the points gap is right. You said if you hold your hand over the carb it will start but will it keep running after you remove your hand. If not it sounds like a vacuum leak. way to check is spray carb. cleaner in cab. when its running, if the idle smooths out it is a vacuum leak, if it starts to die when spraying then there is no vacuum leak. Check vacuum lines also with carb spray as engine is running.

 

Any 4 stroke internal combustion engine has the same requirements. It needs fuel/air mix to the combustion chamber and spark. I seldom check spark with a screw driver (or a finger) in the spark plug wire, I pull a plug and leave it connected to the spark plug wire then ground it and spin. The assures me that there is a source of fire in the combustion chamber.

If it has been converted to 12V it needs 12V to the coil in start mode then 9V (approximate) when it is running. This is assuming points. if it is electronic there are several combinations, for instance a Mallory unilite runs in 9V and an HEI (a viable ignition swap for that engine) runs on 12 V.

Have I muddied the waters enough for you?

 

Thanks Guys.

57 heap- I will check spark with the cap off and with the new spark plugs tonight.

dirtville- it started with my hand on the carb previously- now not even that way. Even when it did start, it took a long time.

porknbeaner- no mud in it for me, it makes sense. the coil was replaced and looks new. I have no clue what brand it is though. I could try and test with my multimeter and see what exact voltage is coming through.

I know its getting fuel because I also see the gasket is leaking on the carb lol. Its the stock- Rochester I guess? Thats what all the other threads say are stock for these. Do the local autoparts stores usually carry rebuild kits or atleast gasket kits for them, or am I going to have to make my own gaskets?

Thanks for the direction guys!
-Spaz

 

Spaz: Not knowing the whole story of the chev and it was me the first thing I would do is a comp. test on the cyls, You need a 100 lbs in a cyl. for it to fire. and all cyls. should be 10% of that,any cyl. that is lower than 100 is bad. If all goes good after the comp. test then I would replace. cap, rotor, points, condenser, plugs, wires,coil, and the carb base gasket and even the fuel filter. The only thing left is the carb itself, might have to be rebuilt or replace. one last thing is the gas in the tank is it fresh, if not add gas treatment to the tank. good luck

 

This sounds to me like the carb and fuel system is polluted with stale/dried gasoline, and it's partly clogged up the carb jets. This is common for old cars which sit around without being driven all winter. A leaky carb gasket indicates that it did sit around without running, until the gasket dried up; and now that you're putting gas in the carb it's leaking.

Anyhow, it doesn't matter how good everything else is or is not: it won't run if the jets are clogged.

Putting your hand over the carb is like pulling the choke knob. You force the engine to pull air through a small opening, and so it sucks very hard and can get some gas into the engine. When you remove the hand, that gas flow dwindles and the engine quits.

 

Ulu- jet was plugged with an 1/8 of muck!

Stripped the carb down to rebuild- gaskets were fairly new, but trash in it and gaskets had small tears.

I am down to the last two brass screws and one is so soft i may have to drill out. Anyone know where i can get a replacement for it?

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Alright... carb cleaned and rebuilt. fuel system flushed including new hoses and filters- fresh gas. Brand new spark plugs- getting spark... yet not firing up. Car it getting fuel... is there something else i could be missing?


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Did you ever hear it run.
If not the is a hole in bell housing and ball that top dead center.
When they line up that's tdc
You could be 180 degs out.
You want tdc both valevs cloased #1 cylinder.
Rotor should point to spark plug wire #1
Check firing order and wires on correctly.
Watch rotor way it turns then put wire on in order.

 

is it properly wired to give it 12 volts while cranking?

 

Did you leave the ignition on at any time? The ignition points may be burned. It can also happen from long periods of cranking. It might cause weak spark or no spark. You can try to clean them up with some emery paper and pull a clean cloth through them.

 

Yes- when i first got it, it would fire after a minute or so of cranking. I changed spark plugs one at a time, so as to not not change order. I was not sure of order, and it ran at first... so i had not messed with it. I gapped the spark plugs at .035- thats was the old plugs were, and went with the R43 plugs.

I will check the firing order tomorrow to say what it currently is.

This is aggravating...


This
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And no i do not leave the ignition on. I actually use the battery out of my daily to work on it, so when im done for the day- back into the daily.

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It has been converted to 12 volts. Could the condenser have gone out- would that prevent it from firing as well?

This is the firing order I found- is that right?

 

The condenser was my first thought when I started reading your thread. They are cheap, give it a try. Good luck

 

Are you getting a healthy spark at the spark plugs?

 

I am going to check the spark and electrical again tonight. If I have no luck, I will grab a new coil, cap, condenser, cables, and new points. It ran and then died and hasnt fired up since. When it ran it ran. That is what has me baffled. It has plenty of fuel and plenty of air... only thing left is something to do with the electrical. The drawback to living way out in the country- when stuff like this happens, have to trailer it for 30-45 minutes just to reach a shop. or parts store.

 

I had similar troubles. Turned out to be a bad condenser. Even the new ones suck. I finally converted to electronic ignition. Tossed the points and condensers into a zip-lock bag and stored in the tool box just in case. But so far, the electronic conversion has been awesome. No more diddling with the dizzy.

 

Or on a mountian top like me.Takes me a half hour just to get to town for parts for my 56 buick wagon.Keep us posted when you get her fired up.Thanks Bruce.

 

I had an old '53 Pontiac that did this. It ran fine one day then not the next.

It turned out to be this little insulator where the primary wire went into the bottom of the distributor.

At some point that wire got hot & cooked it. It quit insulating, so that the distributor seemed to deliver a spark, but not a good enough spark under pressure. It had turned from an insulator to a carbon resistor with low enough ohms to starve the primary voltage.

It took me a long tome to find it too.

I replaced the wire & shot some RTV in place of the insulator.

Sucker started right up.

 

Would just replacing the wire help cause it to fire possibly? Its pitch black out now. Got plent of wire, just nothing to use for the insulation. Can grab on the way home tomorrow though.



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Possibly, if the current one is bad. If the insulator is on the side & also seals to the cap, then it's important that it seals well enough to keep moisture out.

I've seen some really crappy rotor designs lately, and a number of failures due to the fact that rotors which had two rivets now have one rivet and a plastic lug which has draft on it and doesn't really locate things accurately or solidly enough. Worse, the contact itself is shorter and less sturdy, and just more difficult to anchor down.

Too many corners cut means poor durability.

 

is the insulator a replaceable unit as well?

I ran new wires last night and nothing. So I am going to buy a new coil, condenser, points, cap, rotor, cables... replace them all one by one until I find out what is causing the hold up.

 

I haven't read all of the posts so maybe I missed it: do you have a healthy spark at the spark plugs?

 

It is getting spark... I didnt pay attention if it was healthy or not. I was running the starter with a screwdriver in one hand and holding the cable in the other about 1pm sunday afternoon. So I was just checking if I had spark or not at that time. I should invest in one of those ignition jumper/tester setups or make one.

 

It's a rubber or composition plug, molded right on the wire on some cars. On others there's actually a screw through it instead of a wire and the wire is attached there. I don't know what yours looks like.

I just tossed mine out along with the burnt wire, then stuck a new wire through and sealed it in place with black RTV silicone. That seemed to do the trick.

And Yes, figure out what a "healthy' spark looks like. Lots of cars make a spark that is quite visible in the open air, but too weak to fire under pressure.

 

Look for a sharp blue spark that makes an obvious snapping sound as it bridges the gap - between the center electrode and the ground electrode. If you have that your points, coil, wires and condenser are not the problem.

 

I will take a pic of the insulator when I get home after work. I plan to run by the parts store and get everything just in case. I will check the spark first and if it is healthy, then I can always return the parts. If not, can't hurt to put new stuff in for process of elimination. I had to order a transmission dipstick from the guys at TCI yesterday also- since I couldn't find a used one anywhere for the powerglide.

Will let you guys know what the spark is when I can get it tested.

Has anyone made an ignition tester, or are they pretty cheap? I think I should atleast step up from a screwdriver...

 

you can buy a little light for maybe $5 that goes in the wire and lights up if you have a good spark. I take a good spark plug and gap it way out to about 0.150", then stick the coil wire on it, and ground the threads. I hold it in some long pliers with rubber handles and with them I hold it to a good ground.

(Test AWAY from the carb! I watched one fool set a road roller on fire because he tested the spark on an engine with a seeping carb, right on the dang intake manifold. )

If it jumps a .030" gap that proves little.

But if it jumps 1/8" or better you have a viable spark.