Smoke Blew Out of Carb After Shutting Down...

Status
Not open for further replies.
No problem. Yer gittin' 'er and yer lernin' stuff real guuder too! As long as the lights are steady at a given rpm, I'd agree that the alternator is fine. I don't know what you're running, but it's not unheard of for a common el cheapo reman to be faulty right out of the box. Electric fan eh? With a thermo switch and a relay, or running constantly? Probably a stupid question, but I'm asking it anyway.
 
Well, I figured something out today, on of my spark plugs aint firin!! When I pull the plug wire the plug wire is sparkin up a storm, but when I put it to the plug it aint firin, maybe that's why it sounds so low at idle.
 
That will affect idle quality for sure. Have you checked all the others? What's the story on these plugs? Old ass crap or brand new?
 
Plugs, wires, distributor cap and rotor button are about 3 days old, I had a friend that is a motorcycle mechanic look it over and as soon as he heard the motor, he said it aint firin on all cylinders and he started pullin plug wires, he got to number 6 I believe and sho nuff, when he pulled the wire the sound of the motor didn't change at all, but when he held just the wire up to the manifold it was sparkin and arcin like crazy, but what are the chances of getting a defective plug like that?
 
This is weird, I pulled the plug and put 3 new ones on the same cylinder, and they are still not firing, when I hold the wire to something it is getting good spark, when I pulled the plugs they all were getting fuel, they were all wet after I pulled them, I even swapped out that plug wire with another one I had and nothing. Can anyone explain this?

**edit** cylinder 4 and cylinder 5 are misfiring, all the other cylinders are doing great, I put a compression gauge on cylinder 4 and when I first started it the gauge showed 100 psi, after I released the air and let it idle it showed 60 psi, it was idling around 650, now, would this be my heads? Because both heads are brand new (rebuilt all new guides and springs and the whole shebang, or does this sound like a flattened cam? Again, I'm just google reaching here, it's just those two cylinders, I pulled all the other wires and they are doing great!!
 
Last edited:
The chances of having 1 bad plug in a batch of 8 are decent, but 3 is not likely. Did you ground any/all of them with the wire connected to verify that the plugs are throwing spark? I'm sure mayben will chime in on this'n now that's it's taken an unexpected deetoor, jes as soon as he rolls his arse outta beddy-by and puts on his fuzzy bunny rabbit slipperz so's he kin hed down and git on the pooter. Im thinkin' yer gunna be pullin' the valve cover on that bank and with the engine at idle, to see what the valves are doin. Might wait give it an hour or so if you can though.
 
Slow down here...so you are saying ya got only 60psi compression on two cylinders? If so, then those two cylinders got issues.

Pull the valve cover(s) and look at the rockers/pushrods/valves and see if a valve for those cylinders is hung open.

If the plug was not firing when removed, I'd suspect ya did not have it well grounded to the engine for testing. A plug is a very simple device, there is nothing between the tip connector and the end of the electrode to be "bad", it's a single piece of alloy material. Yes, older "resistor" plugs could develop an "open" condition, same for the old "booster gap" plugs with the tiny hole in the porcelain below the boot, those haven't been made since the 70's.

If the engine originally had proper compression on all cylinders, and now it doesn't, ya gotta mechanical issue.

Pull all plugs, block the throttle wide open, disable the ignition so no spark can jump, and do a cold and hot compression test on all cylinders.
 
The plugs are throwing fire when I pull them and check them, I only tested the compression on the #5 cylinder, I put the compression gauge in and started the motor, at first it was at 110 psi, then I hit the compression release on the gauge itself and at idle it stayed around 60 - 65 psi, which I know is sub par, both heads were just rebuilt, new guides and seats and valves and springs, and the pushrods were replaced, basically the entire top end of the motor was just rebuilt, it's weird though, these two cylinders are the two cylinders that originaly had the bent pushrods, I don't know if that means anything, is it possible bad rings on those two cylinders or something? I will pull all the plugs and run a compression test, just to be certain, pull all the plugs out, disconnect the coil so there is no spark on the plugs or wires and put my gauge in hole by hole, or do I pull one plug at a time and test each cylinder? Thanks guys, if I have to pull the motor, I have to pull the motor, but I hope that's not it.
 
grimlock97 said:
the plugs are throwing fire when I pull them and check them, I only tested the compression on the #5 cylinder, I put the compression gauge in and started the motor, at first it was at 110 psi, then I hit the compression release on the gauge itself and at idle it stayed around 60 - 65 psi, which I know is sub par, both heads were just rebuilt, new guides and seats and valves and springs, and the pushrods were replaced, basically the entire top end of the motor was just rebuilt, it's weird though, these two cylinders are the two cylinders that originaly had the bent pushrods, I don't know if that means anything, is it possible bad rings on those two cylinders or something? I will pull all the plugs and run a compression test, just to be certain, pull all the plugs out, disconnect the coil so there is no spark on the plugs or wires and put my gauge in hole by hole, or do I pull one plug at a time and test each cylinder? Thanks guys, if I have to pull the motor, I have to pull the motor, but I hope that's not it.
Click to expand...

While I understand all the work that has been performed, that still does not mean ya don't have a compression issue. I'm fully aware of the background here as we've been following along on this saga for quite some time.

All plugs must be removed to allow the engine to freely spin. The throttle plates must be wide open during the entire process to allow max air entry into the intake, same for the choke...open. Disable spark so that no unexpected fuel vapor can light off. Connect a battery charger so that the battery maintains full ampacity to spin the motor equally while doing the test. Crank over until the highest reading is noted and then stop and record the data.

We are looking for maximum compression reading by cylinder, along with deviation amongst cylinders.

I'd highly suggest this be done with the valve covers removed so you can watch each rocker arm/valve/spring pushrod assembly in turn and visually inspect.
 
Thank you for the clarification, I will get it done this afternoon and post my readings, I know this is taking forever, and it seems like everything is new and nothing can go wrong, boy is that not the case! My saga has only been going on for 4 months!! That's not that long at all!:crazy: ! Thanks again mm
 
Okay, I pulled all the spark plugs, pulled the fuel line (so no fuel will shoot in the cylinders) pulled the ignition from the coil so no fire, opened the choke all the way and opened the throttle plates wide open, then, I connected a battery charger and hooked up the compression gauge working down from #8, I hel the key for 5 seconds each time and counted the exact same turns of the motor, here are my readings

#8 135 psi
#7 145 psi
#6 140 psi
#5 135 psi
#4 135 psi
#3 145 psi
#2 145 psi
#1 145 psi

now what's next oh great ones!!!
 
Those numbers are outstanding with very little deviation. Mayben May suggest you do a hot compression test or a leakdown test next, at first blush there doesn't appear to be any compression issue with that engine. Have you pulled the valve covers yet for observation?
 
No problem with those compression numbers, right where ya expect to see 'em onna decent motor.

So where did that previous compression reading of "100" and "60" on cylinder #4 come from? Was that with the engine hot? Was it repeatable? If so, then one of the valves on that cylinder is hanging/sticking when the engine is up to temp, then as the motor cools it releases.

I'd definitely cut a valve cover in half length-wise to use as an oil shield and to direct oil return back to the sump from the head. Then run the motor for as long as it takes for the valve to "stick" if it's going to, you will be able to watch it do this. May take an hour! With a cutaway valve cover you can drive the motor for hours down the road if needed.

You must be able to visually confirm that all rockers are flooding with oil all the time! And the oil flow must reach both the pushrod ball socket and the valve tip, those are the two critical areas
 
The 60 came on a hot motor after idling for a while then driving about a mile to ride motorcycles, while I was there my buddy that's a mechanic told me not all cylinders were firing, so when I got home I started pulling plug wires, and on #4 and the cylinder directly across from it when I pulled the plug wire it did not change the sound of the motor, the plug wire would arc if I held it close to the plug so fire was getting to the plug itself, I pulled the plug and held it to the manifold and the plug was firing good and there was wet fuel on the plug itself, that's when I connected the compression gauge, and at first it was a hundred + then I hit the compression release and at a rough idle that's where I got the 60 from, I have not pulled the valve covers, and I don't have one to cut in half, but if the valves were causing this on that short of a drive and idle maybe it wouldn't take long for it to happen again, but, as I said previously and I know you all know this but I just had the heads down at the shop 2 months ago with all the valves and springs and everything glass shot and cleaned up and all the valves re-seated and specd, I am not disagreeing in the least, it's just weird is all, what exactly would be the cause of a valve sticking like that? Would that go back to the non oiling rocker assemblies? I have to go to okc for a business trip through Thursday, I'll have all weekend to pull the valve covers, now with that said, there is a knocking noise coming from under the valve cover over the cylinder that is not firing, but like I said the cylinder directly across is not firing as well. Thanks for all the help, I hope I can get this figured out soon, so I can start throwing money in important things like seats and a winch plate!!! Thanks guys.
 
The knocking sound and the loss of compression once the engine gets up to temp means one thing. A valve is sticking due to lack of lubrication. I deal with this constantly! No additive will correct this, the offending rocker(s) is not receiving oil from the shaft feed.

I'm not suggesting the head work was not up to snuff, I am suggesting that the offending valve/cylinder is not oiling even though the others May be.

The only way to diagnose and determine what is going on is to run the engine with a cutdown valve cover and watch it fail...it will! You must have a valve cover in place in order to direct the oil back into the drain hole at the rear of the head, otherwise no oil return to the sump. A properly operating system will not totally flood the rocker chamber, but there will be considerable oil return flow once the system has pressurized and run a few minutes if everything is working correctly.

All this goes back to your original problem with the bent pushrods, those cylinders/rockers were not oiling! And they are still not oiling! You are sticking valve(s) and soon will also bend/break more pushrods, it will never end. You must watch the offending rockers oil in a continuous stream and then determine why they are not oiling like all the others. Root cause for that...the rocker shaft is plugged.

All Ford engines that use a shaft-mounted rocker system could have this same issue as well as all early chevrolet six cylinder motors. The early toyota fj40 sixbanger is just a clone of the chev motor and they were even worse for eating pushrods due to non-oiling rockers.
 
Exactly which cylinders are not effected by pulling the plug wire? You need to post each one for us and not vague symptoms.

The manifold is a dual plane and if one barrel of the carb is not functioning correctly half of the cylinders will miss fire. Every other number in the firing order to be specific.

You have compression, rocker arm oiling, spark and fuel it will run on all eight. So dig a bit deeper. Please post what I requested.
 
Status
Not open for further replies.
Back
Top