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dabaron
Samba Member
Joined: June 21, 2018
Posts: 2745
Location: Philly, mang
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 Posted: Sat Dec 05, 2020 12:29 pm Post subject: Re: cold start drivability issue |
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| crazyvwvanman wrote: |
The /50 in the pin designation means it comes from Circuit 50 which is the starter motor connection to the ignition/starter switch.
This is meant to tell the ECU and the ICU that you are attempting to start the engine.
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so it's not a constant voltage, only present during starter motor activation. do i have that correct?
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1991 Vanagon GL Camper
i had no idea i wanted to be a mechanic |
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dabaron
Samba Member
Joined: June 21, 2018
Posts: 2745
Location: Philly, mang
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| Posted: Sun Dec 27, 2020 4:23 pm Post subject: Re: cold start drivability issue |
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i had about an hour of daylight and it wasn't stupid cold today (37F) so i warmed up the engine and performed a leak down test on cylinder #1, the one with the plug that is showing signs of incomplete burn.
i performed the test twice. one at TDC and one at TDC with the rocker arm removed. identical result.
i could hear air escaping but could not determine the culprit. i'll do more investigating as time allows.
truth be told, i'm not heart broken. i've had a bunch of great adventures and this engine got me there and back. all part of learning, and yes it's still fun.
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1991 Vanagon GL Camper
i had no idea i wanted to be a mechanic |
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DanHoug
Samba Member
Joined: December 05, 2016
Posts: 5918
Location: Bemidji, MN
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| Posted: Sun Dec 27, 2020 5:01 pm Post subject: Re: cold start drivability issue |
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as Tencent once said, a leak down test ain't nuttin' if you don't smack the valve stem tops with a rubber mallet to seat the valves. that said, there's probably a problem. look at the face of the rocker arm and valve stem top to see if there's an issue. i had horribly worn rocker faces and valve top wear due to greatly elongated valve guide wear on a new AMC head.
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-dan
60% of what you find on the internet is wrong, including this post.
'87 Westy & '89 Westy both 2.1 4spd
Past projects can be found at--
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dabaron
Samba Member
Joined: June 21, 2018
Posts: 2745
Location: Philly, mang
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| Posted: Sun Jan 03, 2021 1:58 pm Post subject: Re: cold start drivability issue |
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confirmed the leaking is from #1 exhaust valve, could hear the air in the exhaust pipes. it's a cool sound, but...
cylinder #1 exhaust valve does not seem to be spinning, notice the wear.
cylinder #2 seems to have the same issue.
yes these are stock AMC heads. yes i took a gamble. i'm still having fun.
i'm partially sold on replacing these with tencent heads. it's only money, right?
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1991 Vanagon GL Camper
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