Engine rough running - at wits end

[Dave WM]

rev up engine hold at say 2k. I am assuming you can get it running well enough for this.

load test, load test, load test....by disconnecting one spark wire at a time. listen for a noticeable change. should be a drop of about the same RPM and miss that is consistent with each plug disconnected.

You really need to determine if its a overall cylinders issue or just some not working.

Then you have something new to consider.

 

Edited March 3, 2017 by Dave WM

[siteunseen]

16 minutes ago, the_tool_man said:

I'm not comfortable with the propane torch method, especially right over the exhaust manifold.  I didn't think about the gasket being upside down.  It lined up with all the contours of the head, so I don't really see how it could be.  The gasket is visible in the photo I took of the valve train.  Can you tell?

It's hard to tell in your pic.  Mine was overhanging where this pencil is pointing in my pic.  Check it when you get home.

[the_tool_man]

I tried out the fog machine tonight. It worked spectacularly well. I found a huge vacuum leak around the #5 injector. I must have not gotten the sealing ring lined up when I installed it a while back. I disassembled the rear half of the fuel rail and redid everything. Another fog test showed no leaks.

I turned the key and it started right up. It's smooth as silk. I set idle speed and timing once it had warmed up. It revs freely with no hesitation or popping. I am SOOOOO HAPPY right now!

Thanks to all of you for your help, advice, encouragement and patience. I can be an idiot sometimes. But with your help I've made a big step forward tonight. Thank you.
.

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[siteunseen]

Yaaaay!  Persistance pays off, congratulations. 

[Captain Obvious]

Wow... That's cool. I think I might have to get me one of them smoke machines!

[Captain Obvious]

So I got a question... Having never used one of them smoke machines, what is it that keeps the smoke from just picking a cylinder with open valves and passing through the engine and out the exhaust system? Do you stick a banana in the tailpipe or something?

[the_tool_man]

2 minutes ago, Captain Obvious said:

So I got a question... Having never used one of them smoke machines, what is it that keeps the smoke from just picking a cylinder with open valves and passing through the engine and out the exhaust system? Do you stick a banana in the tailpipe or something?

Good question.  I suppose some does escape.  But the fog machine I borrowed is pretty big, and puts out a large volume of fog (it traversed the 10 foot tube in a second or two).  So there's plenty to go around.  In fact, I had to be pretty meticulous sealing up the intake with my yogurt cup, and even making sure the hose clamp on my vinyl "fog tube" was tight enough to seal it against the vacuum port pipe in the intake.  Otherwise, fog would seep out where I didn't want it to, and obscure things pretty quickly.  Once I fixed the injector leak, I ran the machine a couple more times to verify it and look for others.  At that point, the leakage around the yogurt cup and vinyl tube were still enough to send faint tendrils of fog here and there.  So I had to fiddle some more to eliminate the leaks.  Even my sealed connection at the fog machine leaked a little.

Thinking about this, you don't want this to build any pressure.  It might damage vacuum diaphragms and such.  So having the exhaust pipe be a safety valve is probably a good thing.

[JSM]

Awesome!! That is very cool. Now we need a test drive video!


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[the_tool_man]

3 minutes ago, JSM said:

Awesome!! That is very cool. Now we need a test drive video!


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Soon.  With all the mixture excursions and sitting, I want to change the fluids first.  I also want to bleed and inspect the brakes before I trust them.

Maybe a low speed pass around the neighborhood wouldn't hurt, lol.

[Dave WM]

Nice fix. Now redo the vacuum gauge and see if it looks steady and more in line with what the vacuum should be. I presume all the other stuff like removing the oil fill cap now works as it should.

[Dave WM]

Hmmm  I wonder if simply plugging the exhaust tail pipe and the air cleaner would effectively seal the engine? less fooling with unhooking stuff. Then add smoke at the brake booster port.

[the_tool_man]

14 minutes ago, Dave WM said:

Hmmm  I wonder if simply plugging the exhaust tail pipe and the air cleaner would effectively seal the engine? less fooling with unhooking stuff. Then add smoke at the brake booster port.

I'd be concerned with building pressure if the seal is too good.

I removed the AFM, leaving the rubber hose to the intake in place.  I used the big end of my yogurt cup with a few wraps of electrical tape to plug that.  I'd already blocked off the EGR passage and associated vacuum line.  All I had to do at that point is pull the brake booster line off the hard line on the intake, and clamp the tube from the fog generator to it.  I could have used the barb on the booster check valve.  But the tubing I used was too big, and there wasn't much room around it for fiddling with a hose clamp.  I suspect you can leave the exhaust (and even the EGR) open, and it will still be effective.  Even with some leakage around the tubing and yogurt cup, there was plenty of fog coming out around the injector boss to see the leak.

I need to do a write-up on this, I guess.

Edited March 7, 2017 by the_tool_man