The Stovebolt Site Forums The Shop Area Engine Shop 99.9% sure that's not good...

I was just tinkering with my 54's 235, while the engine was running I pulled one spark plug wire at a time, waited, then plugged it back in. One three of them... the engine sputtered, and then regained composure (which is what SHOULD happen right?). On the other three... absolutely nothing changed.

I need to double check and make sure there IS spark in those wires... but if its not... I'd say an engine rebuild is in order?

Could be bad wires, could be bad spark plugs. As you say see if you have spark at the plugs, then pull the spark plugs to make sure they aren't fouled. Then run a compression test.

Some valves may be adjusted too tight, or burnt.

This statement reminded me of a millwright foreman (now retired) in that when I would tell him one of the machine tools was making troublesome noises and something serious might be wrong he would usually reply "don't start crying till you get hurt". Probably something simple going on here.

Will the engine run if you take all 3 of those plugs off at the same time?

I had this happen to me once on a 270 gmc 6. Turns out I wired it in reverse rotation. For 3 weeks my truck ran like crap, but it was still able to make freeway speeds. I could pull 3 wires at the same time and no difference in the way it would run.

Check Rotation First. 1-5-3-6-2-4 CLOCKWISE!
If you have any doubt about the ignition system, change cap, rotor, points and condensor, plugs, and wires. You may also need to change the coil. I believe the points that are available today are of inferior quality and would reccomend eliminating them by using a pertronics ignition. However the symptoms described do not make the ignition suspect.

If you want to check the engine on the cheap without spending much money, Pull the spark plugs and examine each one. Are they wet, oily, ashy? They can tell you a lot about whats going on with an engine.

Pull the valve cover, are all the rockers adjusted properly? Are all the rockers moving? It is very common for engines that have sat a while to stick a valve,or three and cause the pushrods to bend. This may be the cause of your problems. You might not need an engine build to fix it. You can remove the bent pushrods and straigten them with a hammer on a wood block, or concrete driveway. You can unstick the valves by tapping on them gently with a hammer on a block of wood.

Anyway report back to us with your findings

Didn't have much time tonight, but I did check for spark at each wire. Each wire sparks.
The engine has a high amount of what I believe is blow-by. The light smoke puffing from the breather cap/ vent slots when running, and then drifting out after being shut off.

The plugs (which were new 2 months ago, with less than 20 miles on them, are either blackened already, and there are one or two that are slightly oily.

I wont have time tomorrow for further diagnosing (gotta love work), but I will delve into this more and more as the days come!

I appreciate any and ALL feedback given, and yet to be given!

are the plugs that were oily on the cyl. were the misses were?.. if the plugs were black but dry you may have a carb problem.. what cyl. were not making the engine stumble with the wires pulled?

Alright fellas, did just a few more minutes of investigation.

The cylinders that seem to not be working are 1,5,6. When the plug wires are pulled for 2,3,4, the engine bogs down and just about dies or dies.

I CAN pull all three plug wires for 1,5,6 while the engine is running and the engine will still run as if they WERE plugged in.

The plug wires are in the correct order on the Dizzy, 1-5-3-6-2-4 clockwise

Here are pictures of the plugs.
Plug 1, wet/oily

Plug 2, wet/oily on threads, dry and charred/blackened center

Plugs 3-6 were very similar to Plug 2

Next test I would do is to pull each of the ones not firing and see if they arc to the motor as it is running. Another freebe test is to swap a working/firing wire with one that doesn't. That would verify the wire. Could be the dist cap too.

Dennis

All wires spark to the engine (or to my hand )

Swap the plugs around.

Be sure to take a really good look under the distributor cap for a crack usually seen by a little thin white line. Lots of simply ways to get where you want to go....keep us posted.

run a compression test with all the plugs out to see if all cyl. have near the same compression.. or put a vacuum gauge to a intake vacuum source with engine idling.. reading should 15-20 and steady. if you dont have a gauge put your fingers lightly in the holes with the plugs out and spin the engine you should feel a push..then check back

If you're sure you're getting spark to the end of the wires then I'd say you've got 3 bad plugs. I've bought brand new AC's before and they've gone bad inside 100 miles! You wouldn't think they would go bad but they do. Change those 3 plugs out with new and you'll fix your problem.

I plan on running a compression test, waiting to get the tool in the mail (figured it could hurt to have one around so I bought one instead of borrowing one from one of the FLAPS). I DO have a vacuum gauge... when idling (the engine wasn't warmed up prior to the test though), the guage pulsated between 13ish to 17ish


I will do that tomorrow on my day off!

Alright fellas... Compression test results are here...

Keep in mind, engine was not warmed up prior to test. And all I did was pull the plugs/wires, and grounded the coil.


PLUG #
1) ZERO, didn't register on the gauge at all
2) ~150
3) ~150
4) ~140
5) ~155
6) ~150

After going through a couple times, and seeing it wasn't a faulty gauge... I put some oil down the hole for plug 1, cranked and again, plug 1 came up to ~50

Pull the valve cover and examine the pushrods. Are they bent?

Now might be the time to buy an inspection camera... They are less than $100 and you can examine the cylinder through the spark plug hole.

First pull the valve cover, something might be obviously wrong.

I vote for a stuck valve on the number one cylinder. Other numbers look fine. With zero compression, you either have a valve not closing, hole in top of piston, or blown head gasket. With a blown head gasket, I would think you would get some compression. Putting a bit of oil in the cylinder before doing the compression test will help. If, after adding oil, you get some compression reading then your leak is small (like blown gasket, or really messed up rings). If nothing changes, then leak is big (like open valve or holed piston).

I put some oil in there after the first round of readings, not much, but some and it brought the reading up to 50 on #1

An easy and cheap check would be to pull the valve cover and watch the rocker arms on #1 cylinder. If the push rods are bent you have a stuck valve. If the push rods are not bent, then back off the adjuster to see if that helps with the compression. If that does not help then you need to pull the head to see if it is a gasket (still cheap) or a piston, not so cheap. More time and work and less money. If you get lucky and the compression gets better then a set of new plugs and it should run. Keep us posted.

Thanks for all the suggestions fellas! Sadly work has me slammed, 12 hour days, 6 days (this week at least), so I MIGHT have time for a small peek tonight, but most likely it'll have to wait till Saturday!

Fingers crossed its just a stuck valve/bent pushrod...

Alright fellas, here's the latest update.

Squirted a little oil in all the cylinders. All the compression readings came up to around 200 for 2-6, 1 came up to 25.

pulled the side cover, all the rods look alright from what I can tell. Loosened the adjuster and nothing changed. I took some real short video's if you all wanna check them out.

Pushrod side

Valve side


Thanks to Hotrod Lincoln for PMing me about a Cylinder Leakdown Test!

Could be one or both valves aren't fully closing on #1.
Bring 31 cylinder up to TDC and the BB lined up on the timing pointer. This will ensure that both valves on #1 are fully closed.
Now check for rocker freeplay. You should easily feel the free play on both rockers. If one is tight, it could be holding a valve open. Loosen it if it is tight until you get some freeplay.
You can set the valves cold, just add approx .004 to .005 to the proper warmed up settings.

I had a similar problem on my old 216. I had 3 cylinders that wouldn't pump up [ast 40 psi. Ended up being badly burnt and worn valves and valve seats. Had the head rebuilt, it runs great now.
Good luck
Dave