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kyleader Samba Member
Joined: February 08, 2011 Posts: 519 Location: CA
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Posted: Thu Jul 13, 2017 9:57 pm Post subject: Poor running bug. Revival time! One tight intake, other issues |
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Hey everyone,
Background: avid bugger until college got in the way. Sad to say, but she sat for a couple years with only a few drives here and there to the beach, to some VW bug shows, etc. Maybe 100 miles, if that, over 2 years.
Graduated... and time to get her running like a top again!
New spark plugs, new cables. New fuel filter & fresh fuel. Checked timing. Cleaned and rebuilt zenith 32 NDIX with 010 distributor with petronix. Still ran poor (stumbled off idle).
Seemed like a tuning issue, so I swapped in friends EMPI 34pict3 and 019 distributor with petronix, re-timed, still same issue persisted. Stumble off idle unless you gradually increased the gas pedal. Hard idle and poor control of idle from the carb.
Checked the valves today (should have done this sooner, but I hadn't put even 500 miles on the car since last valve check so figured it couldn't be those) and found that cylinder #4 had a freakishly tight intake valve. About 0.25" of adjustment later (yes, likely a quarter of an inch) and that valve is in spec clearance wise. She now idles much better, especially for not yet adjusting the carb, but she is LOUD! Which makes sense considering how much play that rocker has when that cylinder isn't at TDC.
Interesting observation: turning the engine clockwise, waiting for the exhaust to open and close, then the intake likewise, TDC of cylinder 4 doesn't seem to allow the intake valve to fully return to closed. It is more extended at 20 degrees passed TDC CW than at TDC. Is this right? Perhaps I just didn't notice this on the other 3 cylinders.
Nevertheless, something is up and I am not too excited about the possibilities! Can this be a bent push rod, bent valve, sticking valve, worse?
What would you all recommend be my plan of action list?
I plan on inspecting the push rod first, but if that checks out I want to ensure that the next thing I should check is that valve by pulling the head off & dissasembling.
Any thoughts or advice is greatly appreciated! _________________ My bug build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=465143
Happy Bug'in... |
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Abscate Samba Member
Joined: October 05, 2014 Posts: 22670 Location: NYC/Upstate/ROW
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Posted: Fri Jul 14, 2017 2:35 am Post subject: Re: Poor running bug. Revival time! One tight intake, other issues |
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College didn't get in the way, you just got a lot of bad career shit out of your way for the rest of your life...congrats!
Pull the valve cover, and the rocker arm and check that all the valve stems are even with a straightedge. If number 4 is sticking up, the valve seat has been pounded and you need to act on it to save the cylinder head.
You will need to read just valves in replacing the rocker arm, too. _________________ .ssS! |
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kyleader Samba Member
Joined: February 08, 2011 Posts: 519 Location: CA
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Posted: Fri Jul 14, 2017 8:35 am Post subject: Re: Poor running bug. Revival time! One tight intake, other issues |
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Abscate wrote: |
College didn't get in the way, you just got a lot of bad career shit out of your way for the rest of your life...congrats!
Pull the valve cover, and the rocker arm and check that all the valve stems are even with a straightedge. If number 4 is sticking up, the valve seat has been pounded and you need to act on it to save the cylinder head.
You will need to read just valves in replacing the rocker arm, too. |
Thanks! I'll get to that this weekend. I'll report back the findings. Thanks for the advice _________________ My bug build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=465143
Happy Bug'in... |
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kyleader Samba Member
Joined: February 08, 2011 Posts: 519 Location: CA
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Posted: Mon Jul 17, 2017 8:23 pm Post subject: Re: Poor running bug. Revival time! One tight intake, other issues |
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Removed the rocker arm subassembly. All pushrods are ok. Also, all 4 valves extend to the same length when the rocker arm assembly is removed.
Re-did valve check and adjustment and idk what happened last time but this time, back to normal and tightened up that valve in question.
Must've been awhile since I last did valves ha! _________________ My bug build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=465143
Happy Bug'in... |
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