Fouled Plug #1

[YourBuddy'sTruck]

My trucks been doing the stutter over 45 mph again.
Recently replaced Coil, Module, cap, rotor. Newer wire(6 months).
350 with HEI and a Quadrajet.
Swapped out plugs and found #1 fouled.
Here's a pic.
Why would only #1 be fouled?
Wouldn't be worn rings or would be all fouled, right?
Is this a symptom of it missing at cruise speed?
Would it be a valve out? It will backfire out the exhaust if I gas it at 45 mph?
Help me. I need direction. Lost and clueless.

Plugs are 8,6,4,2-7,5,3,1 left to right.

[Longhorn 70]

does it look like oil or is it dry? Can't tell from the pic. If it's dry, could be a freaky plug or wire. If it is oily, rings, valve guide with a stuck valve....

Does it idle smooth? If so, you could even have a broken spring with worn guide or bad valve stem seal.

[cooperhw]

Run a compression check. It will tell you if you have a broken ring, or other stuff,,,,,,,,,,,
It's easy and cheap to do. Most of the discount auto parts stores will sell you the loaner tool and when you are done bring it back and get all your money back. If you don't have one already.

[YourBuddy'sTruck]

Starts and idles great.
I'll try a new wire too, before pulling a cover.
Pulling a cover would be something I've not done since a teenager!
(That's 25yrs ago! Ouch!)
It's dry. And I've a compression Testors.
What compression should I see?
Thanks guys!

[Longhorn 70]

your compression should be within 10% of the other holes....just a 10% between high and low.

Also bring that piston up to TDC on the compression stroke. Push some compressed air in to the cylinder and listen to where you hear it leak from....

If you have an ohm meter you can test the wire. No more than 20K for the wire resistance. About 1K an inch is OK.

[YourBuddy'sTruck]

A short 14 mile trip and #1 is black again.
Tested the wire with another so I know it's not the wire or plug.
(then i recall that my timing light verified that)
Ran compression test on #1 and #3 and both were 125, so I'm guessing my rings and such are good.
Also, my valves are closed at the proper time.
So, how would I find out what causes it to miss over 45mph?
Would that be a sticking valve? Fine at 35mph, but sticking at higher speeds?
If so, how would you check that while sitting in the driveway?

[jdbas71]

My 307 did that. it had a bad head gasket. Never used water.

[GASoline71]

Is it a rebuilt engine? Or the 40 year old stock engine?

Gary

[tranz am]

My big big block had that same issue for a while. I was burning some oil. Ended up being a bad intake manifold gasket. It was pulling oil into the port from under the intake under high vacuum on deceleration.

[YourBuddy'sTruck]

It's 40+ years old!
Gonna try some lead substitute.
Been thinking new heads, but not till winter.
No real way to check the gasket but to pull it, huh?

[tranz am]

Originally Posted by YourBuddy'sTruck7168995

It's 40+ years old!
Gonna try some lead substitute.
Been thinking new heads, but not till winter.
No real way to check the gasket but to pull it, huh?

You would really just have to pull the intake off to check the intake if its leaking on the underside.
Since its 40 years old Its probably just time For a rebuild.

[YourBuddy'sTruck]

I do burn oil, but thought it was rings. Looks like some maintanence in my future.
No time for a overhaul until after October.
I only use the truck once a week, maybe twice.
But I do have new heads in budget for this fall.
I'll let you all know if the Instead'o'lead helps. If it does, I'll know it's a valve for sure!
Thanks for the help. I try to read more than write here, but I find all the threads with the info I need never have an ending or follow up.
Really wish every one would be better about that. Otherwise it's threads full of darts being thrown at a problem.

[GASoline71]

New heads with new seals and a 3 angle valve job will do nothing but suck more oil past the rings on an engine that old.

If it were me and I couldn't rebuild/overhaul until the fall... I'd just keep an eye on that plug and keep cleaning it off and replacing it.

When an engine is worn out... there is nothing you can do to make it run better than to overhaul it. Everything else is just a "Band-Aid" fix.

Gary

[YourBuddy'sTruck]

I hear you on Band-Aid fixes.
I did get under the hood after you all nudged me to the intake instead of the heads and...
Lo and behold! Half the intake bolts were loose?!?
(How many years, after you buy it, can you blame the P.O.?)
So I'm thinking on pulling the intake and installing a new gasket this holiday weekend.
And the reason I've budgeted new heads is these ones are leaded and hardened seats would do me well.
Then again, pulling the whole thing for a propper rebuild in the fall would be best. Time? Money? And lack of both may win out?

Any advice going in to pull the intake? I have not done that since about 1983 and I've landed on my head a LOT since then!
Cheers!

[RichardJ]

Drain the coolant first. Get a manual and torque wrench if you don't have them already.

[swamp rat]

i agree with GASoline71, i have seen it way too many times someone thinks freshening the top end and a new cam will make a poor engine a killer machine, it ends up being a smoker.

Just do the intake manifold for now, and be sure you seal the threads on the bolts that enter the eater jackets, if ya don't your gaskets will fail in about 3-6 months.

Save for a rebuild in the mean time.

[GASoline71]

Yup^^^ I would just tighten the manifold bolts to spec and call it good. Save your coin until you're ready to rebuild in the fall.

Gary

[YourBuddy'sTruck]

Thanks Fellas. X10!
Input to ThruPut...money better spent!

[YourBuddy'sTruck]

What a great day for "shade tree" work!
I took the time to pull the intake and clean it up for new gaskets today.
While finishing up the cleaning, I noticed that my #1 Piston's Push Rods are loose!?!
The furthest forwards only a little, but the next one back is kinda scary loose.
The parts look all good and not any wear or obvious maladies. Even the little retaining clips below look fine.
This is officially beyond my scope of knowledge on this engine.

Is this a matter of adjustment at the Rockers?
Help! I'm in to deep to back out now!
Can I go forward with the intake? Do I need to pull the covers with the intake still off?
Nice weather here in Ohio for another day at least, but I do want to button this thing up and need to hear back from somebody that know what my next step would be.
Thanks in advance, and I hope your Memorial Day Weekend is off to a great start!

[WarMonger]

subscribed

[YourBuddy'sTruck]

Well...I read and read and decided while in there...
I adjusted the Valves with this procedure.
Worked great, but still some slack in the push rods.
Not really slack, more like a few thousandths of backlash.
Could someone confirm that this was the correct thing to do.
I have to get Valve Cover Gaskets before proceeding tomorrow, but will be stitching it up as early as I am able.

[swamp rat]

Copy from another forum then added my wording for clarity.

Valve Adjustment The Quick Way:

With the engine OFF and spark plugs removed so that you can rotate the engine with less effort.

1. Get #1 piston to compression TDC, Cam gear at 12 o'clock crank gear at 12 o'clock.

2. Adjust the intake valves on cylinders 1, 2, 5, & 7 by loosening the rocker nut until play is in the pushrod then tighten the nut untill the up and down play in the pushrod stops and then tighten the rocker nut 90 degrees.
(I'll add to this; do not spin pushrod when adjusting move it up and down, also some people like to turn the nut only 1/8 of a turn instead of 1/4 turn)

3. Adjust the exhaust valves on 1, 3, 4, & 8 in the same manner.

4. Rotate crank 360 degrees to get cylinder #6 to compression TDC, Cam gear at 6 o'clock and crank gear at 12 o'clock.

5. Adjust the intake valves on 3, 4, 6, & 8 in the same manner.

6. Adjust the exhaust valves on 2, 5, 6, & 7 in the same manner.

Another post:

This method works very well for a running engine. (do not do this unless the static adjustment is done first)

Loosen the adjusting nut of one valve until you hear it "clicking". Slowly re-tighten the adjusting nut until the clicking stops. Tighten an additional 1/4 to 1/2 turn. Repeat this procedure for the remaining valves.

This procedure is done with the engine idling. If you rev the engine up you will get quite a mess, even with the clips and the modified valve cover.

[YourBuddy'sTruck]

Thanks Swamp Rat.
That is exactly what I did...the cold version.
Thanks for confirming. Now I can zip this up with some new gaskets and see if I can remember to reconnect everything?
Cheers!

[68C15]

worn valve seat would give you tight push rods. Worn cam, bad lifter, stuck valve, etc. will make the push rod loose. Lets just hope it's not a rocker stud pulling out of the head. How do you feel about eating ramen noodles or mac-n-cheese 3 times a day for a while so you can fund the rebuild?

[YourBuddy'sTruck]

Originally Posted by 68C15

How do you feel about eating ramen noodles or mac-n-cheese 3 times a day for a while so you can fund the rebuild?

Yeah...I know it's not good in there. Need it to run till after Halloween.
Then I can pull it apart for a rebuild.
I only use it for about 100 miles a week for hauling deliveries.
Looking at the workmanship of the previous owner, it's a little to be desired.
Leaks everywhere and even with, what appears to be, several tubes of Permatex?

I'll find out tomorrow and in the weeks to come?
Any way to see the cam lobes in place? I don't think so, not without pulling them, right?