Hydraulic Lock

[Eric Kropp]

Some time back a I started a thread called hydraulic lock. The engine turned over good, stout battery and starter. Then every now and then it would just stop cranking like it locked up or acted like it wanted to start backwards. It would kill the battery real fast when that happened. Well it did it again, this time I thought about it for a minute, pulled the dizzy cap, and found it damp and the terminals were pretty funky. I dried it out and tidy'ed up the terminals and it fired right up. I think it was cross firing inside the dizzy cap. That would explain why it would just ''stop'' cranking when a wrong cylinder would fire at the wrong time and could even push the piston backwards. Oh well, makes sense to me.

Eric<><

 

[dangerranger83]

Having a bigger dizzy for the duraspark setup helps with that a bit since the terminals are a bit further from eachother.

What I have been told to do is spray the cap with WD40 to help keep moister from building up. Not sure though if your suppose to spray on the inside or not. I have never had this problem though. Also you dont want your wires to be crossing eachother either, spark voltage can jump out of the wire to another and cause this too.

 

[--weezl--]

if your cap was full of water, that's your issue for sure!

spraying a quick shot of wd-40 wouldn't be a bad idea, though i would use a rag to remove as much moisture as possible first...

if water got in there, your cap is probably cracked and needing replacing also... for the cost of a new cap, just replace it! plug wires should be replaced... every 5 years? i think it is... because as danger mentioned, wires can arc and lose voltage, and cross arcing is possible (though unlikely) in the wires

 

[enginepaul]

Thank or the update.
A cross fire would - or could - stop an engine and cause it go go backwards when trying to start. Moisture in the cap is rare but not unheard of.
Bad wires will cross-fire. Run the engine when dark; spry water (from a bottle) on the wire and if you see arcs, replace the wires. Bad wires probably wouldn't do what you describe, but checking them can't hurt.

 

[Eric Kropp]

This engine builds up a fair amount of moisture in the crank case. It shows up on the dipstick frequently. I think what is happening is the moisture from the crank case finds its way up into the dizzy. The engine has 360,000 miles on it and has a fair amount of blow by. I have found that there is more blow by than the pcv system can get rid of. There is probably enough wear in the shaft to the dizzy to allow moisture to climb up there.....I guess. I just like the fact that it starts!!!!!

Eric

 

[dangerranger83]

Somehow you can put the words 360,000 miles, 83 ranger, carb, blow by and California in the same sentence and it be legal.

 

[--weezl--]

This engine builds up a fair amount of moisture in the crank case. It shows up on the dipstick frequently. I think what is happening is the moisture from the crank case finds its way up into the dizzy. The engine has 360,000 miles on it and has a fair amount of blow by. I have found that there is more blow by than the pcv system can get rid of. There is probably enough wear in the shaft to the dizzy to allow moisture to climb up there.....I guess. I just like the fact that it starts!!!!!

Eric

honestly, i don't believe you, the small amount of moisture (as compared to air) in the crank case, multiplied by the blow by, and the fraction that is distro shaft wear, there is no way in hell you have enough moisture buildup in there to cause running problems!

change your cap, my money is on ambient moisture getting in from hot cold cycles and the vent on the cap or a lack of seal around the upper and lower cap sections...

and fwiw, i had a cap that didn't seal correctly, it took probably 10 or so full drops of water distributed evenly on my 5L's cap to cause a running problem...

 

[kimcrwbr1]

This engine builds up a fair amount of moisture in the crank case. It shows up on the dipstick frequently. I think what is happening is the moisture from the crank case finds its way up into the dizzy. The engine has 360,000 miles on it and has a fair amount of blow by. I have found that there is more blow by than the pcv system can get rid of. There is probably enough wear in the shaft to the dizzy to allow moisture to climb up there.....I guess. I just like the fact that it starts!!!!!

Eric

Try a PCV for a large block V-8 and see if it takes care of the blowby and valve guide seals can be changed without pulling the heads.

 

[kimcrwbr1]

I do think weezi is right about ambient air causing the moisture but my theory is when you stop the engine the pressure from the blowby in the cap goes away and as the dizzy cools it pulls ambient air in the cap and the air condenses into moisture. A larger volume PCV may reduce the condition but do your engine a favor and change the valve guide seals. I am sure the cat is toast from the burnt oil going in there too it wouldnt hurt to change the cat also.

 

[Eric Kropp]

I actually run a PCV from a 400 Midland small block and that helps the pressure in the crankcase. It won't pass the smog in California with that PCV because it causes the engine to idle to fast because of the increased air into the intake. I changed the valve seals a couple years ago. The only real work I had to do to get it to pass smog is to ''adjust'' the thermactor to bring more air in at idle. I have a friend that has a Sun Pro analog smog engine tester. I take it to him and we check it out before it goes to the shop. As far as where the moisture comes from in the dizzy, I noticed it after I changed the seals on the valve stems. The crankcase built up more pressure, blow by became more apparent, the dip stick got rusty, and the dizzy cap gets wet. The best thing is, I can fix it when it weirds out, regardless where the moisture comes from.

V465<><

 

[--weezl--]

if you have a pcv that is different, and causes a high idle "because it lets more air in" then you essentially have a vac leak... good bye fuel economy, good bye spark plugs ect

 

[Eric Kropp]

It still get 18 mpg city and highway (mostly highway), and 20 or so when driving just highway. But when I run the higher flow PCV I don't get the rust on the dipstick and the snot on the end of the dipstick when I check the oil. I'll change the plugs if i have too. I figured I would rebuild the engine before October, (next smog check). Then I got a company truck from work to drive, so I will probably will try and pass smog again.

Eric<><