Not Firing on all 8 cylinders

[AirborneC10]

Took the truck out (1970 C-10, 350 crate motor, Accel electronic ignition) out to my motorcycle shop this morning - felt fine.

On the way home it felt strange, like it was struggling somewhat. Got it home, messed around with cleaning the carb (Edelbrock 650) and still not working right - heard a tick-ticking sound but not like valve tick (though it could be). Then I felt the exhaust, the passenger side exhaust was warm, the driver's side exhaust was noticeably cool. Very cool.

So clearly I am not firing on all cylinders on that bank (at least that's what I'm assuming). I pulled the plugs, none were gunked up (and they're new - about 3000 miles on them). The plug wires were checked and rechecked (even shocked the piss out of myself with one of them).

However that doesn't mean there isn't a break in the wire.

So I am on the hook tomorrow to get some new plug wires (needed it anyway as the ones in there are way too long).

However I am looking for suggestions as to what else it could be. I'm hoping the new wires fix it, but would like some other things to have ready to check if it doesn't.

The exhaust are straight pipes to exhaust manifolds and no crossover so I know that the cool pipe is running straight from the driver's side cylinders.

The electronic ignition is sparking (it runs, but there is a chug-chug at the cool exhaust pipe, almost like an old steam train).

Thanks guys.

Mike

[cdowns]

i'd take out one plug at a time ground it to the exhaust turn the motor over and see if its sparking//at the same time checking overall condition of the plug as well as checking for the proper gap

[texanidiot25]

When my carb was junked up, and ran stupid rich, it would chug and barely run at low speed (basically missfiring at idle real bad) and was running so rich that 3 cylinders were noticeably cooler than the other 5 (based on touching the header tubes). Could be something out of tune on the carb.

[MT71c-10]

I'd take one of those lazer temp guns and shoot each of your header tubes, or manifold ( a little less acurate on a manifold ), about 1" from the head, that would tell you which cyl. is acting up. Also check your cap on the dist., look at the contacts and see if any are corroded, cracked, bent, etc. Also, Plugs can be bad and not look it. Thats probably where I would start.

Also check your idle mixture screw ports, in the primarys of your carb, if you screw them in too hard they will break the aluminum and cause a very rich condition, and a truck that runs like crap!

[slednD1]

moisture is a problem with edelbrock carbs,the jets are in the bottom of the bowl and if one drop of water "very common with todays fuel-its how they change octane ratings"gets in the bowl it goes right to the jet and fuel cannot pass.but it sound like you have a distributor problem.check your rotor and cap carefuly.and ignition advance springs and weights flying apart under cap may be problem if using cheap aftermarket HEI.debri gets stuck on pickup and so on..if all is ok try unbolting carb and turning upside down in a pan to see how much water you have collected.good luck

[slednD1]

any high reving lately??? could be valve spring,rocker stud or arm??check compression

[AirborneC10]

I did notice that it seemed there was water in the exhaust on the side in question, and it hasn't rained here nor have I washed the truck (though it did snow a **** ton last week).

I'll replace the wires just because I've been meaning to and also check the carb.

It's weird that it just suddenly started. The gas was fairly low, but then I filled up and it's still acting that way.

[spinning wheels]

Sounds like one of your plug wires is arcing. Best time to check, is at night. Just open the hood with the motor running and you can then see the blue arc going towards the metal. I have had several plug wires burn on the stock iron manifolds. It wont take much to cause the problem. Just get some good guides to keep them off the pipes.

Then again, maybe a lifter went bad?

[MT71c-10]

Originally Posted by AirborneC10

I did notice that it seemed there was water in the exhaust on the side in question, and it hasn't rained here nor have I washed the truck (though it did snow a **** ton last week).

I'll replace the wires just because I've been meaning to and also check the carb.

It's weird that it just suddenly started. The gas was fairly low, but then I filled up and it's still acting that way.

I'd pick up a new fuel filter while you are at the parts store, you may have picked up some junk from the tank and plugged it up.

[AirborneC10]

Well I cleaned the distributor, removed the carb and cleaned it (as best I could without tearing it apart), and replaced the wires with all new wires.

Still have a chug-chug and some smoke out of the driver's side exhaust.

Pulled the valve cover gaskets and they're all moving up and down, however some of the rods are spinning, some arent. Some will spin when it is stopped, some won't.

I don't know much about valves (I'm a 2-stroke motorcycle guy) but I would assume that some rods should spin in certain positions, and they shouldn't in others?

Also they should all spin at times when running, and there seem to be two cylinders where they don't spin at all at any time.

[68shortfleet]

Are you running a dual plane manifold? I have seen a plugged idle jet kill all of the cylinders on that plane of the manifold. Basically it was running on every other cylinder at idle. Rev it up and get it off the idle circuit and it ran great.

Jason

[AirborneC10]

So is the consensus still that it should be something in the carb or the distributor?

Nothing in the valves or motor? I was a bit concerned that some of those rocker arms or whatever they are spin freely when the motor is running (and when it is off) but others don't spin at all.

I have one of those Edelbrock manifolds - all this stuff came on the truck when I bought it.

[monte0185]

I would venture to say its prolly distributor related. If you have a good set of insulated pliers or spark plug wire pliers you can pull each one as its running one by one and the engine will either bog down or stay the same. If it stays the same at idle you know what cylinder its happening on. If its multiple then Id look in the carb area. Oh and just for grins and giggles go to wally world and get you a 99 cent bottle of isoprofile alchohol (rubbing alchohol) and pour it in your gas tank. That will get rid of any water in the system.

[slednD1]

re-adj. your valves one cylinder at a time,v-c off looking at #1 cyl. rotate eng.while watching valves,the one on the left is exh. so watch the one on the right open completely and starts to close.about half way closed means eng. is on compression stroke and you can now adj.the exh. valve "the one on the left" back off adj. not until pushrod spins freely now slowly tighten until you just take out all the lash.once you reach zero lash turn adj. nut another 1/2 turn in. Exh. valve is now adj.now adj. int.valve by continuing the rotation watching the exh. valve you just adjusted start to open slowly rotate eng untill exh valve gets to about half way open and repeat adj for intake valve-repeat on all cyl's/again-int opens and half closed adj. exh..exh.just starts to open adj. int.after this is done check compression on all cyl's and post results,should be no more than 15 psi variation. let me know what you find and good luck

[AirborneC10]

Can I just adjust the valves while it is running by backing off the nut until it clacks, then tightening until it doesn't, then tightening 1/2 to 3/4 turn?

If so, does it matter which valve I start with? Just start at the far left of the cylinder bank and work my way back?

[slednD1]

yes and sorry havent checked on ya but no it does'nt matter really where you start,just do it quickly cause of oil splash.hint:cut out an old valve cover to put on durring adjustment,this should keep oil under control. good luck again.

[AirborneC10]

Originally Posted by slednD1

yes and sorry havent checked on ya but no it does'nt matter really where you start,just do it quickly cause of oil splash.hint:cut out an old valve cover to put on durring adjustment,this should keep oil under control. good luck again.

Sweet. Thanks. I ended up ordering a new distributor, coil and wires (Summit Racing had a deal on the entire set for $90). Of course now the battery is dead so I have to charge it.

My distributor was butt. The inside was rusted, the weights were ovaled out and just swung around freely, etc. I'll keep the thread updated on what works out.

[El Jay]

Originally Posted by monte0185

I would venture to say its prolly distributor related. If you have a good set of insulated pliers or spark plug wire pliers you can pull each one as its running one by one and the engine will either bog down or stay the same. If it stays the same at idle you know what cylinder its happening on. If its multiple then Id look in the carb area. Oh and just for grins and giggles go to wally world and get you a 99 cent bottle of isoprofile alchohol (rubbing alchohol) and pour it in your gas tank. That will get rid of any water in the system.

I respectfully have to disagree.
Isopropyl is anywhere from 50-70% water.

If you're going to put alcohol into your gas tank, go to the hardware store and get some denatured alcohol. It's 10%, or less, water.

[AirborneC10]

New distributor, wires, plugs, HEI coil, etc didn't fix it.

Two of the cylinders I was questioning had over 90 PSI. Didn't check all four on that side.

When running there is a visible "steam" cloud from that exhaust and water is blowing out. Clear, clean water, not mixed with radiator fluid. It seriously looks like an old steam train chugging from that pipe.

Thoughts?

Also adjusted the valves with the motor running. Yes, it's messy.

[AirborneC10]

I learned of an old trick of holding a dollar bill at the exhaust. If it is sucked in then you have a burned exhaust valve (or sticking one).

And, yes, it sucked in.

So I either have a burned or sticking valve.

1: Is there any way to tell if it is just sticking and, if so, can it be fixed with some kind of engine goop?

2: Would it be more cost effective to buy new heads and replace both of them at the same time

or

Remove the head on the one side and take it to a machine shop? How much would that cost (approx?)

[AirborneC10]

Also: If I go the new head route, how can I tell which heads to purchase? This is a GM crate motor but other than that I don't know anything about it.

is there something on the heads in the motor that I can look at and tell what is compatible?