Hello all Hope I'm posting in the correct section; apologies if it is not. Mt project car with a generic SBC gen1 350 was running fine back in Feb. It was parked for 7 months. (at the time there was 1/4 tank of gas) It's been topped off since. Now when I took it out, the car vibrates/shakes more then before. It's more then extra vibration, I would say it's shaking even. Not only can I feel it. But I can also see it in the reflection of the phone when it sits in the dash mounted hold. Anyone might have an idea of what might be causing the shaking? It feels as strong as before so all cylinders should be firing. I've ran 1/2 a tank of gas through it now, and it did not get any better. I was going to try to clean the carb and change the plugs. But I am doubting that is the problem. I just find it puzzling since nothing was changed on the car. Any advice or comments would be appreciated. Thanks Regards K
Drive it to see what engine rpm the shake occurs. Then stop the car, put it in neutral and run the engine up to that rpm. If the shake occurs when you do this, the shake is engine related. If it doesn't the problem is drivetrain or chassis related. Once you know this, you can start to run down what is causing the shake.
Anyone might have an idea of what might be causing the shaking? It feels as strong as before so all cylinders should be firing. Should be, could be, take a minute to know for sure. Guessing and surmising never fixed anything. Dropping 1 cylinder would make it shake at idle.
Raise the hood, and run the engine while in a blacked out garage; see if there's a "light show" coming from any of the plug wires. I tend to go along with the "mice ate my homework" scenario. Maybe the cam went dry from sitting, and now it's going flat? There could be a hundred different things going on; time to start trouble shooting. I am Butch/56sedandelivery.
Condensation in the distributor cap from sitting can result in tracking inside the cap and cause such problems.
Is it a flat tappet cam? A cam lobe could be going away from a dry start up. If it is a flat tappet cam do you run a zinc additive in your oil?
That tells me that it is missing so your problem is carburetion, ignition or compression. If you open the throttle to maybe 1500 or 2000 rpm while setting still, does it smooth out or is it still rough?
Start it up, warm it up, let it idle, start pulling 1 plug wire at a time off plug or dizzy. If that plug wire makes no discernible difference in quality of idle that's a weak or dead cyl. A good plug wire pulled of will make it stumble worse.
Another quick way to locate a dead cylinder is if you have a temp. gun. Check each exhaust port and the dead one will be the cold/colder one. If it's got headers a little spit on your finger will sizzle on the working cylinders and not on the dead cylinder.
You mice think I’m messing around? Say hello to my little friend! Sent from my iPhone using The H.A.M.B. mobile app
Where did you get an AK for your cat Deuces? Now my two want one. I never worried about my two boys fighting. Brothers will occasionally get into it for whatever reason. Until one day when I heard the youngest one yell, "FIX BAYONETS".
It might have a booger in a passage in the carb from sitting with gas in it. Sometimes they will self destruct/self clear, sometimes they need a shot of aerosol carb cleaner and an air hose. Pull the fuel pump inlet line and blow back into the tank in case the pickup has a cling-on. Check all the vacuum hoses and external carb vacuum plugs to see if something cracked or fell off. Look closely at the cap, rotor and plug wires as mentioned.
As the guys said, check the simple stuff. It's best to have a pair of those insulated spark plug wire pliers to pull plug wires off a running engine though. The spark won't hurt you near as much as what ever you hit when you jump back. I picked up one of the "hei" spark testers the other day to check the plug wires on an ot rig. https://www.amazon.com/OTC-6589-Ele...ywords=HEI+spark+tester&qid=1605843651&sr=8-2 You can do the same thing with a spark plug if you ground it out though but this makes it simpler. Still check the simple stuff, look inside the cap for condensation especially if it is a 60's early 70's Ford engine. Every time it rained real hard in Central Texas my boss would send me out to some guy's place with a can of WD-40 and a roll of paper towels to dry the guys distributor cap out. I think I went out there three times in a two year period of time.
Hello all, it's been a while. Been sidetracked with work and personal stuff. Anyways just thought I'd give an update. Thanks all for the above comments and suggestions. I've replaced the spark plugs and wires. A few of old wires got a little scorched from touching the headers, so I replaced them. I've also added insulated boots to keep the news ones protected from the heat and tied them up to they won't accidently touch the headers anymore. After the swap, the car did not vibrate as much, only a very little. So I thought the problem was fixed. Drove it a few weeks ago, for ~15 miles, parked, had lunch, restarted and drove home another ~15 miles, no problems at all, not even a hot restart problem (which I thought I fixed with a heat shield around the alternator and insulation around the fuel line) Drove it again this Sunday, first leg of the drive was fine, 2nd leg was a bit longer and more spirited. Parked it, but could not restart it. The hot restart problem was back and really bad cause it was a hot day too. I had to wait like 5 hours for it to really cool off before I could restart the car. But after getting it started, the shaking was back! (I've now ordered a spacer plate to help keep the carburetor cooler. The spacer under there now is aluminum and it's a heat magnet. Hopefully that will fix the hot restart problem.) As for the shaking being back, I'm guessing that the 6 or 7 times I tried to start it up during those 5 hours, it might have flooded the engine and fouled the plugs. It's just a guess as I don't know what else would cause the shaking to come back. Should it foul the plugs that easily? Maybe the carb needs to be cleaned or checked? Attached are pics of the plugs that came out before the new plugs were swapped in. I noticed the side with plugs 1,3,5,7 seemed dirtier. Other side doesn't seem so bad. That seems a bit odd.
It’s running rich what’s your fuel pressure ? Electric or mechanical pump ? What type of carb ? Carb settings ? timing ? Hook up a vacuum gauge snd see what the readings are . a phenolic carb spacer helps with heat .
Thanks VandenPlas (Guessing from the name, your a Jaguar fan?) I don't know the fuel pressure. I have an electric pump. The system does not have a return line; it's a dead head system. (I bought this car used and it came like that). Reading online, the deadhead style while not the greatest seems usable. I'll pick up a vacuum gauge this week. I don't know the timing The car ran fine for the 1st year I had it (except for the hot restart problem) but the shaking didn't happen until after the 2nd year. Previous owner had installed the carb about 6 months before I bought it The carb is a Holley 600 (I'll need to inspect it and find the list number for more details) I don't know the jets being used. Car came with the Holley manual# 199R7948-5 Here is the exact one in pdf from the Holly site. https://documents.holley.com/199r7948-5rev6.pdf
VANDENPLAS came from a time I worked at jag and thought it was my final stop on my career path hollys like 5-6 psi Buy one of the combo vacuum / fuel pressure gauges and you can check both. what are your carb settings ? uphere in Canada we don’t have as much ethanol in our fuels and are still able to get non ethanol fuel rather easy. I know for you guys it’s a real issue. do you know your carb and timing settings ?
The Jalopy Journal
