Valve Cover/Crank Case Vent

[97XJSP]

I've been chasing a stumble/ carb backfire under sudden acceleration just off idle. A little choke would fix it so I suspected lean mixture from clogged fuel system. Cleaned carb, new fuel pump, fuel lines, treated gas tank, plugs, wires, cap, rotor, adjusted valves, points blah blah. Still need to put a timing light on it though. Anyway, while pulling the valve cover and adjusting the valves, I noticed that the crank case vent hose was a pretty sloppy fit. I pulled the hose off and plugged the fitting at the manifold... the stumble almost disappeared and idle dropped considerably so it's leaking somewhere. I don't recall seeing any type of PCV valve when I had the cover off, but I wasn't looking for one. So, can I plug the vacuum at the manifold and vent the crank case hose to the atmosphere or the air intake before the carb?

Also, I was scoping out the ignitor bolts for adjusting the timing. I noticed that the screw, which you can see from underneath, was missing Isn't that the one that's the "mounting" screw, and the adjustment is the nut which you can see looking down from the top? Anybody got an idea what size that screw is on the bottom? It's a pain not being able to drive the truck to the store and test a few sizes!

Thanks for all the help! After tinkering last summer and most of the winter, I might actually get to pull the top off and go for a cruise this weekend if I take care of the reg/ insurance

[brute4c]

Although I dont have the size offhand, the one up underneath is for timing the ignition...the one that one can see looking down from the top is the mount to the timing cover.

I had a problem with the crankcase vent...for a while I ran a breather cap on a hose in place of the stock breather hose...so the hose came up most of the way to where it was stock and then a breather cap, like you find in a valve cover, was added and clamped into the hose.
Worked fine.

This was before I found a new pcv valve and sorted that part out correctly...I think you are saying you dont have one or see one...it should be in the hose from the oil fill cap neck to the intake....see the -20 manual, fig 2-17...that shows it...It is in Chapter 2, Section 11, Maintenance of Fuel System.

[97XJSP]

Well I guess I do have one... I figured it would be on the valve cover end for some reason. Is there any particular reason for the vent being plumbed into the vacuum, other than pulling the fumes into the intake? I think I'll just cap the vacuum for now, and try to get it running properly.

the one up underneath is for timing the ignition...the one that one can see looking down from the top is the mount to the timing cover.

I'm confused... In the manual, it says that the top is the "adjusting nut" and the bottom is the "mounting Bolt"

-20 manual, figure 2-31 chapter 2 section 14.

[brute4c]

True...confused me too.

The top one doesnt allow enough motion to account for timing chain stretch over time...every so often, the bottom one has to be moved to be able to get back in the right timing...so I just use that one...one could use the top one, then every so often move the bottom so that the top only could again be used...

[97XJSP]

Ok, thats what I was thinking since both are connected to the same "collar" thing. Since the bottom screw was missing, I tried turning the ignitor but it didn't budge. I didn't try too hard, since the truck runs ok as is and I didn't want to mess it up, not having a timing light handy. This is my first time messing with a distributor, but it seems like I could just pull it out and take it with me to get the proper size screw, clean it up, and put some anti-seize on it to make it easier to adjust the timing. Think it's worth the trouble? When reinstalling, I just need to make sure the oil pump shaft and the ignitor shaft meet up properly, seems to be outlined well enough in the -20.

[brute4c]

The ignitor housing is steel where it goes into the timing cover and the timing cover is aluminum. They love to corrode together and stick so that you cannot turn the ignitor for timing purposes and to remove it.
I have used a torch very carefully to heat the aluminum in the area and then try to turn the ignitor...heat the little spout on the timing cover that the ignitor goes in to.
After you heat it a bit, being careful not to overheat the aluminum, turn it, or try to...reheat again and try again...never seen this not work.
I know others have used a big lever of some kind or even hit it with a big hammer to turn it...if you use some heat and then a lever to get it going, might work good too.

As far as lining it p, if all you are doing is taking out the ignitor, not turning the motor or removing the oil pump etc., then I would take the top off the ignitor, put a mark on the body of the ignitor where the rotor point before pulling it out....when you go to put it back, line up the rotor and good to go...the only other position it would try to actually seat in is 180 degrees off...so if you are close to the mark you made, no sweat getting it back...not like you can be 10 degrees off.

Cleaning the steel part of the mating surface with sandpaper is a good idea...I took a piece of sandpaper and cleaned the inside of the spout on the timing cover too...I took a a small hose adapted onto my shop vac and shoved it down in there to clean up any residue.

The anti seize is a must in my book...even 10 years after putting in a civvy ignition, which has the same sticking problem due to the dissimiliar metals corrosion, it was easy to time and remove.

[97XJSP]

Well as usual I should have left well enough alone. That thing was stuck pretty bad. I tried everything and it didn't even budge until I used the 4lb mini sledge with a block of wood. After about an hour of working it back and forth and soaking it with PB blaster, I was able to get a screwdriver in there to pry out while I continued to hit it back and forth. Cleaned it up, took it to the hardware store and got the bolt (1/4-20) and put it all back together. Turned it over and nothing. Checked the shaft twice (will it even actually go in the wrong way, 180 degrees off?) That checked out, checked my plug wires twice. Finally pulled off the cap and pieces of the coil fell out So... I'm guessing the coil is trashed, do you think the damaged coil could have fried anything else if it was shorted or something? And is anything else, like the condenser, sensitive to a million blows with a sledge hammer?

[97XJSP]

just tested the coil with a meter... Primary resistance is 4.6 ohms and secondary is 14.39 K ohms. Seems like those are acceptable numbers... Guess I need to check some other stuff.

[brute4c]

Not sure what else might be damaged...the cap could be cracked...seems you would have found that.

Can you have someone crank it while the cover is off to see if there is any spark at the points or at a plug?

Make sure juice is getting in...make sure the points are a good ground by checking continuity...

Some of the coils use an external ballast resistor...some use an internal one...if yours has the external one, maybe it has an issue...

I would make sure you have power in to the coil and follow the path of power toward the plugs...at some point it sounds like it is getting lost.

[randygar]

First thing I'd do is clip a test light between the coil/points connection and ground, crank it over, and make sure it blinks correctly. If it does blink, and it looks right (about half on/half off), suspect a bad coil or a secondary side problem. If always on, the points are open. If always off, check the other side of the coil. If off, check your power wiring. If on, disconnect the points, then check the other side again. If on, the points are shorted/never opening. If off, coil is bad. Be sure not to touch the test light doing this - the primary can reach 300V, and it hurts.

--Randy