The Stovebolt Site Forums The Shop Area Engine Shop 235 symptoms 6 cyl seems sick

my 236 6 cyl. is scaring me a little, and I need some advise.thought I would spill out the issues and see if anyone has a remedy or two.
1. it idles rough. seems to bog down when given gas at the pedal. exhaust sputters, and kind of chokes you in the garage.not real smoky but not clear either.
2. doesnt seem like any adjustments on the carb screws really make much difference on the rough idle, and removing the air cleaner doesnt change the rough idle, you can really hear the air sucking in. i am very careful to bairly move those screws and do them one at a time.
3. i removed the hand lever throttle, to give the gas pedal more play, idles rough before and after.
4. if you choke or not, the idle is same engine idles rough and sputtery, almost dies when given gas, kind of undrivable.to get it to start I have to push the foot starter and the gas smashed to the floor at the same time, or shoot started fluid in it. even though it seems to be over gassed or running rich in the way it acts, it kind of actually seems starved for gas, theres really no gas smell like when a car is flooded, more of a choke you kind of to much heavy exhaust smell instead.
5. I have had a few of these trucks and all the ones I have had give a little smoke or exhaust out of the valve cover breather hole, this one seems to give more than normal. the valve cover it came with was pretty much destroyed, so I switched to another valve cover, same design etc, but very clean on the inside. does this one need to burn in or something or is this valve cover cap just letting more out than others I have had? with the bogging down and extra smokiness I am kind of fearfull of ring issues? possible? leaks oil too by the way.
this truck sat for a year in the garage while I did a frame off, the gaas tank is new, lines should be clean. my limited opinion is carb adjust so I removed hand throttle cable to clean up carb a little, fuel screw is set to 2 1/2 turns out, and the other screw is set all the way out. by the way, it is a little tough to start and idles like crap, but it will sit there and run without dying, unless you try to give it gas. and I drove it in the subdivision and there were no issues, sounded and smelled like crap, but ran around and made it home. I also removed the choke cable from the equasion to see if that made any difference, and no it didnt. I am taking advise I read on here in a forum posting and walking away for a while instead of starting it on fire and pushing it down the driveway. it sure is depressing when nothing you are doing is working. I love these old trucks and the stock-er the better, I dont want ot give up on it.

Vacuum leak??? Check carb/float etc. Check plug wires make sure they are in correct order. Also go step by step through tune up specs in manual if none of the above helps.

Sounds like the carb set and dried out making for internal leakes and no accl. pump, also could be year old gas.

Your fuel mixture screw should be 1 1/2 to 2 1/2 turns out - somewhere in there should give it good idle. The other adjustment screw should be adjusted to give it about 500 rpms at idle. The only other carb adjustment is the float level. I'd check those, along with the suggestions mentioned above. Also check each plug to make sure it's getting a good spark.
Samantha

Rough idle & nasty exhaust could mean a miss on one of your cylinders. This would explain the hard to start as well.

Check your plugs & see if any are fouled. It is surprisingly easy to foul a new plug.

You may want to reset or replace the points as well. I've had this same issue with my old tractor when it gets water in the distributor.

CARBKING has said many carb problems are really misdiagnosed and are really electrical problems. As Midget Farmer says check your distributor including timing.

I am still fighting this same battle with my 216, and haven't won yet. This is what I have done and should establish a base line for your diagnosis.

Start with a compression check and eliminate low compression and bad valves.

Replace the Points, plugs, condenser, rotor, cap and plug wires, to eliminate any of those issues.

Set your timing IAW the specs.

Make sure your firing order is corrrect, 1-5-3-6-2-4.

Check your vacuum at the manifold. Should be around 18.

Check your vacuum Advance. Apply vacuum to the line and it should hold steady.

Sounds like a valve might be sticking. Do like mike says. Run a compression test. With insulated pliers pull one plug wire at a time & see how much it effects the running. If you can isolate the cyl/s causing the problem it might lead us to the cause.

just give it a basic tune up............and replace fuel filter..

carbs are usually the last thing you want to fool with, at least I have found that to be true in most cases..

Is this a 1956 235 truck engine with mechanical lifters, or is it a 1956 235 car engine with hydraulic lifters?

Have you adjusted the valve lash?

[If this is a truck engine, and there is a stuck valve, doesn't something have to give/bend/break?]

joker wins. a tune and very slight screw adjsutments ot the carb did it for me. its on the road now. find a oil leak I have ot contend with now