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Pirranah
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76 Posts
Discussion Starter · #1 ·
Okay, so I replaced the valve stem seals to get rid of that "blue puff"@ startup. I was careul to do it text book, now my 4.3 runs like crap.

First of all it is a 85 block with an Edelbrock cam/intake, and carb'd, non vortec, no computer.

Symptoms;
*Sputtering, like a missing cylinder.
*The carb can be leaned out to zilch & still runs w/ out choking out.
*Vacuum gauge used to read steady 17" of mercury, now fluctuates real fast btx 8" & 13" & smooths out when given steady throttle up to 2k rpms
*no more smoke @ exhaust, but lots of condensation on Driver side
*only one side of engine heats up-driver side, the other ex. Maniold is cool to the touch.
*timing is dead nuts on

I am a total loss, the seals were done textbook, so any suggestions would be greatly appreciated. What ever is causing the vacuum luction is prolly my issue, but I don't know what that might be.

Here's what I'm thinking;
*carbutetor
*plugs/wires
*ignition control module
*valves
I just don't know how to go about this.

Thanks to everyone!
 

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8,782 Posts

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It's "Neanderthal"
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5,411 Posts
Okay, so I replaced the valve stem seals to get rid of that "blue puff"@ startup. I was careul to do it text book, now my 4.3 runs like crap.

First of all it is a 85 block with an Edelbrock cam/intake, and carb'd, non vortec, no computer.

Symptoms;
*Sputtering, like a missing cylinder.
*The carb can be leaned out to zilch & still runs w/ out choking out. It must be running at idle on the primary circuit. Back off the idle speed screw to close the primarys or find whatever is holding them open, then adjust the mixture screws
*Vacuum gauge used to read steady 17" of mercury, now fluctuates real fast btx 8" & 13" & smooths out when given steady throttle up to 2k rpms Check the valve adjustment, and are the locks and retainers seated?
*no more smoke @ exhaust, but lots of condensation on Driver side
*only one side of engine heats up-driver side, the other ex. Maniold is cool to the touch. Cool to the touch - it's not firing on that side, do a compression test, I think it's zero because the valves aren't closing.
*timing is dead nuts on

I am a total loss, the seals were done textbook, so any suggestions would be greatly appreciated. What ever is causing the vacuum luction is prolly my issue, but I don't know what that might be.

Here's what I'm thinking;
*carbutetor
*plugs/wires
*ignition control module
*valves
I just don't know how to go about this.

Thanks to everyone!
Go back over the valves
 

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Pirranah
Joined
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76 Posts
Discussion Starter · #5 ·
UPDATE: I did a compression test & found #2 cyl totally dead. Loosened the rocker arms & re-lashed valves on compression & intake stroke by 1/4 turn increments. Then compressioned the faulty cylinder after 1/4 turn increments. The exhaust valve only took 1/4 a turn, and the intake valve took 3/4 a turn. Funny huh? Then it pumped up to 150psi. BAM!

Also, I found another reason that it was running crappy. The dizzy was burnt up @ the condensor, and the wires coming of the base of the dizzy were dry-rot!!!! This was my problem with running like crap the whole time B4 the valvestem seals. I didn't notice until I was doing the timing & felt a little buzz!

Warrantied the dizzy out & its running GR8!

Thanks for all the help guys!
 

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i saw what you did there!
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3,573 Posts
thats what happens when you set rocker nuts incorrectly

good job and congrats :p

its zero lash plus one full turn when cold

or 3/4 turn when warm

with valve closed completely, IE the lifter on backside of lobe


most ppl have a real hard time with this, i dont know why
 
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