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View Full Version : Engine: Another day, another problem to work through: engine runs rough.



DougHolverson
08-27-2017, 09:31 AM
The 289 in the '57 Silver Hawk runs rough and needs nursing to stay running. It won't idle. It won't rev, that just runs rougher and misses. It has a lot of water condensation out of both exhausts. No real black or blue smoke that I can see, but I'm going to get a second set of eyes back there. I have vague suspicions about the carburetor. Any ideas?

I'm planning a few things already. I'm going to get some fresh gas just to be sure (it's running out of one of those red plastic tanks to ferry gas to lawnmowers). I'm going take the top off the WW and check float level. I'm going to check the dwell. Maybe if things run long, start checking compression. I got a nifty screw in compression tester with that stash of Stude stuff that I got from Sioux City.

mbstude
08-27-2017, 09:45 AM
Have you given it a full tune up?

jclary
08-27-2017, 09:56 AM
Have you checked your vacuum advance diaphragm? Checked for intake manifold leaks?Are you gravity feeding the gas from that container? If so, is it elevated enough to supply good flow? Some easy checks that might find the problem before you begin tearing things apart.

PackardV8
08-27-2017, 10:25 AM
Have you given it a full tune up?

X2, Mattew; I won't touch a problem car until it has new spark plugs, plug wires, distributor cap, rotor, points and condensor. By that time, the problem is often gone.

jack vines

DougHolverson
08-27-2017, 10:44 AM
The gas can is sitting on the floor. I'll put it in the trunk after I get some fresher gas.

So far, the carburetor has been rebuilt, and the car has new points, condenser, resistor, and coil. I have cap and rotor sitting around that I can install later today. If that doesn't help, I'll run for wires and plugs. At least one of the plug wires is a little bit mouse nibbled....

I have suspicions on that carburetor, but I'll put that off until I go through all that ignition stuff.

58L-J8 Guy
08-27-2017, 10:56 AM
The gas can is sitting on the floor. I'll put it in the trunk after I get some fresher gas.

So far, the carburetor has been rebuilt, and the car has new points, condenser, resistor, and coil. I have cap and rotor sitting around that I can install later today. If that doesn't help, I'll run for wires and plugs. At least one of the plug wires is a little bit mouse nibbled....

I have suspicions on that carburetor, but I'll put that off until I go through all that ignition stuff.
Doug, Re-check your point gap.

DougHolverson
08-27-2017, 11:00 AM
That too. It was on .015. I supposed that it doesn't mean that it stayed on .015. I'll recheck it when I install cap and rotor.

I'm toying with checking the compression when I'm changing the plugs. I mean they're out and this car is a good candidate for stuck rings.

altair
08-27-2017, 12:18 PM
There are so many things that can cause your conditions. Firstly separate your ignition and/or fuel issues. Ensure the carburetor is clean and all the jets are clean, float is set and there are no leaking gaskets, carb base gaskets and intake gaskets. A simple check is to spray some water around the carb base gasket and along the intake gasket and see if it stumbles. This can also be aided with a vacuum gage it can tell you a lot. Your point gap is listed at .013 - .018 therefore .015 is the middle of the road. Your condition appears to be fuel and air related. You may have additional internal issues but eliminate the outside first.

DougHolverson
08-27-2017, 02:13 PM
It runs well now!

I moved the temporary tank from the floor to the trunk and that didn't make any difference. I replaced the cap and rotor since I already had those sitting around and that made all the difference. I got things dialed in since then.

I'm going to get the plugs and wires from Rock Auto at a more leisurely pace.

T.J. lavallee
08-27-2017, 04:24 PM
Congratulations! Nothing serious. That's what I like about old cars. It's usually either spark or fuel. Start with that and one can usually find the culprit, not always, but most of the time.

Blue 15G
08-27-2017, 04:46 PM
Have you given it a full tune up?

Matthew, thanks for your reply, it brought back good memories. In 1973 I was working part time while in school at a discount department store automotive department (long before the Wal-mart days, at least in our neck of the woods), and back then people would come in and ask us, of all people, why their car wasn't running right. We would reply just as you did, and you wouldn't believe the number of blank stares, deer in the headlights look, or the response, "What do you mean?"

Dan Timberlake
08-27-2017, 05:55 PM
FWIW I'd expect a visual inspection of the old cap and rotor to reveal what was "wrong" with them.

Sometimes removing moisture or any oily film is enough to restore proper function.

Even premium brands used to consider diagnosis/troubleshooting a precursor to parts replacement.
http://oldcarshopmanuals.com/manuals/1955/1955%20Buick%20Shop%20Manual/10-Electrical%20Systems/image8.html

DougHolverson
08-27-2017, 08:57 PM
The cap looked as good as new. The rotor only looked slightly tarnished.

doofus
08-28-2017, 07:42 AM
I'd bet there were carbon tracks in that cap! Doofus