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wil84911

Failing Valve Guides?

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Why would you assume that? Is it oil residue? Valve guide seals maybe 

Take a propane flame to it and see if it burns off .

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18 minutes ago, madkaw said:

Why would you assume that? Is it oil residue? Valve guide seals maybe 

Take a propane flame to it and see if it burns off .

Just based off my research. Thanks

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way rich. OR wrong heat range. is it burning oil (blue smoke) or gas (black smoke).

1st thing is to get a compression test to gauge the overall health of the compression. is this a FI or carb?

If FI check all the sensors/fuel pressure/connections/grounds. Check for leaking cold start valve. fuel pressure is critical and must be controlled for FI to work.

If carb IDK.

Edited by Dave WM

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You should add your car details to a sig, or at least tell people what you're working with in your posts. 

Pretty sure it's a 240Z, based on the stuck heat lever post.  Looks like the plug was firing for a while.  Need all of the details on the engine though, and the plug, to make a better guess.

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7 minutes ago, Dave WM said:

way rich. OR wrong heat range. is it burning oil (blue smoke) or gas (black smoke).

1st thing is to get a compression test to gauge the overall health of the compression. is this a FI or carb?

If FI check all the sensors/fuel pressure/connections/grounds. Check for leaking cold start valve. fuel pressure is critical and must be controlled for FI to work.

If carb IDK.

New to me 71 with triple webers. No smoke. Thx

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1 minute ago, Zed Head said:

You should add your car details to a sig, or at least tell people what you're working with in your posts. 

Pretty sure it's a 240Z, based on the stuck heat lever post.  Looks like the plug was firing for a while.  Need all of the details on the engine though, and the plug, to make a better guess.

Ok will do. I've been technically unsavy lately. Must be old age. 

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choke function working correct? (wont start without it, pulling it when warm makes engine stubble rich).

Edited by Dave WM

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how long were those plugs in use? do you drive it aggressively (open it up and rev up to 4-5  k between shifts or do you loaf around at low rpms a lot)?

Edited by Dave WM

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4 minutes ago, Dave WM said:

how long were those plugs in use? do you drive it aggressively (open it up and rev up to 4-5  k between shifts or do you loaf around at low rpms a lot)?

Sorry don't know just got the car. Yes I intend to give her an Italian tuneup once register and with new plugs. I drive in between agressive and safe/normal. 

Edited by wil84911

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before drawing any conclusions you should get new correct plugs, drive for a week and pull them again. For all you know those plugs could have looked that way when installed (used plugs). It happens.

If the car is not smoking, pulling strong, no misfires, chances are it need nothing but running.

 

Edited by Dave WM

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All responses acknowledged and will report back any updates. Thanks so much to all. Great forum. I see myself hanging out here more often. Cheers!

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I should say that failing valve guides is not a bad guess, although seals would be more specific.  They will leak more oil at idle under high intake system vacuum and dirty up the plugs pretty quickly.  Then when you start driving much of that will burn off.  My original engine had bad seals and would run rough after putting around town, then would clear up after I gave it one of those high rev tune-ups.  It was fun for quite a while to have a reason to go beat on the engine, trying to figure out why it ran so much better afterward.  After I removed the engine and took the head off, I noticed oil draining down the intake and exhaust valves after just a little while.  The seals weren't sealing at all.

There's quite a bit on the site about changing valve seals.  Pretty easy, I think, and might make a big difference.

In short - I second madkaw's thought, in Post #2.

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6 minutes ago, Zed Head said:

I should say that failing valve guides is not a bad guess, although seals would be more specific.  They will leak more oil at idle under high intake system vacuum and dirty up the plugs pretty quickly.  Then when you start driving much of that will burn off.  My original engine had bad seals and would run rough after putting around town, then would clear up after I gave it one of those high rev tune-ups.  It was fun for quite a while to have a reason to go beat on the engine, trying to figure out why it ran so much better afterward.  After I removed the engine and took the head off, I noticed oil draining down the intake and exhaust valves after just a little while.  The seals weren't sealing at all.

There's quite a bit on the site about changing valve seals.  Pretty easy, I think, and might make a big difference.

In short - I second madkaw's thought, in Post #2.

Thank you. That's the plan. Drive it with new plugs, recharged k&n filter and monitor. 

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11 hours ago, Dave WM said:

choke function working correct? (wont start without it, pulling it when warm makes engine stubble rich).

No choke

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22 minutes ago, Travel'n Man said:

On more. Does your car have a AFR Meter? If not that needs to be your first purchase in my opinion


Sent from my iPhone using Classic Zcar Club mobile

This? Reads 5 consistently when given a little throttle. 

 

IMG_8610.PNG

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That's a fuel pressure gauge.  5 psi might be a little high for Webers, but I don't know Webers.  Float bowls and valves are all similar though and 5 seems a bit on the high side.

AFR stands for Air Fuel Ratio (even though air actually contains fuel) and AFR meters are used to help make adjustments to hit a certain fuel air ratio.  But the old school ways will work also. No offense Travel'n Man.  People have tuned many carbs before AFR meters came about.  They're great for fine tuning but he can make a lot of progress just by eye, and butt, from where he's starting.

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I still do not have a AFR for my triples. Still on my list. I have gotten the plug reading to a nice light tan color with out it so far.

Are you running an electric fuel pump?

Stock mechanical pump?

Both together?

Do you have a FPR installed?

5 psi is a little too high. It could be actually even higher. I am not too keen on some of those gauges.

Float levels definitely need to be verified as well before anything else.

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I still do not have a AFR for my triples. Still on my list. I have gotten the plug reading to a nice light tan color with out it so far.
Are you running an electric fuel pump?
Stock mechanical pump?
Both together?
Do you have a FPR installed?
5 psi is a little too high. It could be actually even higher. I am not too keen on some of those gauges.
Float levels definitely need to be verified as well before anything else.


Both fuel pumps I was told.


Sent from my iPhone using Classic Zcar Club mobile

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