Blown Head Gasket

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I did another valve adjustment after getting the truck running and it got warm. I also re-torqued the head bolts and the manifold at the same time. Maybe the engine cooled off too much before I got to the valves. I could try again.
 
At 2200, your vacuum is going to show a little low. I think like 18 or 19 will be the best you can get.

However, the way it is fluctuating it’s either vacuum leak or valve needs to be readjusted.

Suggestions,
I can’t tell in the pic, but where is the vacuum advance to the carb connected? I see something connected to the distributor, but don’t see the hose coming around the front, which in stock form I think it would come around the front and then the connection above the butterfly plate on the carb. It looks like you have a non-emissions carb, so I think that would be one connection.

Maybe cap all vacuum connections off and then see if that will stop the oscillating. I’d do that first before adjusting valves.
 
Again, thanks guys for the input.
There are 2 vacuum lines coming from the distributor. Both are currently routed around the back top of the valve cover. 1 goes to the base of the carb between the carb and the valve cover. The other is hooked to a port that comes off the intake I dont know if it matters which one goes to which. Please tell me if it does. Otherwise there is a vaccum line that comes off the intake manifold to the brake booster. And one that goes from the carb spacer to the charcoal canister. Then there are 2 lines coming off the top of the charcoal canister. 1 goes to the gas tank and the other is capped. All other vacuum line ports are capped with pretty new rubber caps that fit snug. Oh, there is a vacuum line that running from the bottom of the air cleaner housing to the solenoid that opens the cold air intake. Also the PCV. I think thats all I can find.
Hopefully that is not as confusing as it all sounds. I think everything is hooked up as before. Except im not sure on the 2 lines coming from the distributor. (It was running great with idle around 650 and vacuum about 18.) I took pictures of how it was before but after I removed those 2 lines. Doh!
 
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Spike Strip said:
The vacuum advancer on your distributor has an inner and outer diaphragm chamber. Cap the line to the inner chamber, and cap off wherever it was going.
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This helped. Still not all the way back to how it was and I can't get it to idle below about 890 but it helped for sure.
Also with the air cleaner off I can hear a pretty audible sucking sound into the carb. Is that normal?
 
Yes. Normal.

You can't get the idle down with the idle adj screw? ( It's often confused with the fast idle screw, which is right behind it. Look at the FSM)

Do you have a timing light?
 
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This is the one I'm adjusting called the idle mixture screw in the FSM. Ya? The one to the right and behind is the fast idle adjuster screw ya?
 
If I'm seeing the pic clearly, the finger is on the idle adjustment screw. It adjusts the throttle plate opening. The one behind it is fast idle, for cold engine. Mixture screw is on the side facing the valve cover.


Is that a City racer carb?
 
Ok. Ya. I'm adjusting the one I'm poiting at as well as the one between the carb and the valve cover. These are the 2 I understood I needed to switch back and forth between while doing the lean drop. I do have a timing light. That has the tack on it.
 
I think my carb is a Chinese one. The PO put it on when he did the sog delete. He gave me the original one. But I had this thing dialed in so well before the head gasket blew, I figured this was the way to go.
 
Pull the line to the charcoal canister and cap where it came from and see what happens (cap at carb spacer from your description). If your charcoal canister isn’t functioning properly it’s going to hinder tuning.
Where’s the PCV hooked to?
Did you try sucking on the line to the distributor and see if it held? If it doesn’t hold then the diaphragm is bad and is a vacuum leak source.
You should be able to run the mixture screw (on valve cover side of carb) about 2 turns out from lightly seated, then fine tune from there for vacuum. If you set it there and it won’t idle, then it’s the dance of timing and curb idle adjustment (the screw you are pointing to), provided you’ve found no vacuum leaks.

You can also cap every vacuum port you have, brakes and all, then get the carb and timing dialed in. After that, start adding 1 vacuum “accessory” at a time and readjust. I’d start with brake booster, which should require no adjustments unless the booster diaphragm is leaking, in which case it needs replaced.
Next I’d add PCV and you will need to slightly adjust because it’s an intended vacuum leak essentially.
Then charcoal canister if you’ve determined it’s good and properly functioning. (It most likely isn’t).
Then vacuum advance after you’ve determined that diaphragm isn’t leaking, but no readjusting for vac advance.

Wow, that got long. Others may do this differently but this way isolates each potential leak as you go.
 
Thanks @Skreddy.
Can you explain what you mean by "does it hold" how would I check this? I understand that I would disconnect the vacuum line at the base of the carb and suck on it like a straw but how would I know if it holds?

The PCV is connected to a hose that comes from the bottom of the air cleaner.

I like your approach to finding the vacuum leak by isolating each source.
 
70 FJ40 said:
Thanks @Skreddy.
Can you explain what you mean by "does it hold" how would I check this? I understand that I would disconnect the vacuum line at the base of the carb and suck on it like a straw but how would I know if it holds?

The PCV is connected to a hose that comes from the bottom of the air cleaner.

I like your approach to finding the vacuum leak by isolating each source.
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Yep just like a straw. Essentially sticking your finger over the end of the straw and sucking. If you suck, you’ll feel it building vacuum where you can’t suck anymore. Stick tip of your tongue at the end of the hose and it should hold that vacuum.
You can also do it by blowing into that hose and you shouldn’t be able to blow hardly at all. Can use a hand vacuum pump too if you have one, but it’s way more fun sticking dirty car parts in your mouth.

For PCV, I’d connect it to a direct manifold vacuum source like the carb spacer (where you’ve got the charcoal canister now) or the intake manifold.
 
70 FJ40 said:
I'm admittedly a novice mechanic so it could be something simple or elementary. :D
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Maybe, but you are quickly becoming a better shade tree mechanic than most fresh red seal “technicians”. None (or very few) of the techs trained in the past 20 years would be doing any better. The people helping you here will get you through it.
 
@Skreddy I’ll keep an eye open for your 60 in Spokey. What part of town do you hang out in? We live up at the top of the 395 north of Kettle Falls and are usually in the modern 60 (black 1958 with 2.5” lift and 33s. BC plates on it).
 
joseywales said:
@Skreddy I’ll keep an eye open for your 60 in Spokey. What part of town do you hang out in? We live up at the top of the 395 north of Kettle Falls and are usually in the modern 60 (black 1958 with 2.5” lift and 33s. BC plates on it).
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I’m just north of town, near the Wandermere golf course. I go to Chewelah often. I’ve got buddys in kettle. Keep an eye open for projects for me….
 
Skreddy said:
I’m just north of town, near the Wandermere golf course. I go to Chewelah often. I’ve got buddys in kettle. Keep an eye open for projects for me….
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PM sent…
 
Ok. Thanks again for everybody's help. After taking the last couple days to celebrate Thanksgiving and going to the Malheur NF for Christmas tress, I think I've got it running pretty well again. You were right @Skreddy, I think the main problem was the charcoal canister. I plugged all the vacuum ports, then as I added things back in, I re-routed them as you suggested. I left the charcoal canister plugged off.
I did some learning of how to properly use my digital timing light and now the truck is timed to 7° before TDC. I was able to get the idle down to 650 RPM using the lean drop method. Vacuum hovers pretty constant at 19. The exhaust fumes smell a little rich but otherwise its running quite well. Just in time too, because Monday it goes into the dealer to get the fuel tank replaced under recall.

Thanks again, everyone. This forum is awesome.
 
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