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dubsteez79
Samba Member
Joined: November 22, 2017
Posts: 194
Location: star nc
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 Posted: Fri Jun 07, 2019 5:38 am Post subject: Engine ground(s) |
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How many engine grounds are there? And where are they supposed to be located? Would a lack of one or internally corroded one cause "no run" or would it possibly just misfire?
I got my new coil on last night, adjusted valves(.004) again because I had rockers off to mess with the pushrod tube seals, static timed it to 8ish btdc. Idles pretty good and revs good but when I hold the throttle about 50% or so to check max advance, it bounces around and misfires. Will clear up if i goose it while this is happening. Im wondering if an engine ground could cause anything like this. I think I grounded it with an old strap but I cant remember. Its been a long time since I put all of that back together. Im at work right now so I cant look but am just pondering possible solutions.
Engine spec: 1600 DP, dual 34's, engle 110, 009 dist., cleaned up stock heads, header |
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glutamodo 
The Android
Joined: July 13, 2004
Posts: 26323
Location: Douglas, WY
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| Posted: Fri Jun 07, 2019 6:42 am Post subject: Re: Engine ground(s) |
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The drivetrain has one ground - the strap that bypasses the front transmission mount.
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Andy T.
IMAGE NOTE: It has been noted that Chrome based browsers may have issues in displaying my vast image library, which use non-secure links and are on an FTP server. Images should still be viewable if the link is clicked though.
I do not know how to fix this. All I can say is it all works fine for me with what I use, Firefox. |
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AlmostHeavenWV_VW
Samba Member
Joined: October 12, 2017
Posts: 1966
Location: WV
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| Posted: Fri Jun 07, 2019 8:03 am Post subject: Re: Engine ground(s) |
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| dubsteez79 wrote: |
| How many engine grounds are there? And where are they supposed to be located? Would a lack of one or internally corroded one cause "no run" or would it possibly just misfire? |
Locations of ground straps to transmission (and engine).
https://www.thesamba.com/vw/forum/viewtopic.php?t=584162&highlight=ground+strap
Pics from that thread:
Body mount location #1 attached to transmission mount (common for pre 1973)
Location #2 connected to stud on rear frame horn (common for 1973+)
So long as the ground strap is in good order and all connections are clean just make sure it's all connected from a clean point on transmission and a clean point on body- electricity doesn't care where the ground is.
| dubsteez79 wrote: |
I got my new coil on last night, adjusted valves(.004) again because I had rockers off to mess with the pushrod tube seals, static timed it to 8ish btdc. Idles pretty good and revs good but when I hold the throttle about 50% or so to check max advance, it bounces around and misfires. Will clear up if i goose it while this is happening. Im wondering if an engine ground could cause anything like this. I think I grounded it with an old strap but I cant remember. Its been a long time since I put all of that back together. Im at work right now so I cant look but am just pondering possible solutions.
Engine spec: 1600 DP, dual 34's, engle 110, 009 dist., cleaned up stock heads, header |
hmmm... valves to .004? That's too tight.
Anything is possible, but a misfire doesn't really point to a bad ground strap. Typically the car will simply be SLLLOOOWW to turn over with the starter (since the starter draws the most Amps at the turn of the key).
Why did you replace the coil? Tested it and proved it to be faulty? or was the misfires happening before the new coil? Need more info here.
Any backfires?
Is that 009 dist. a OEM Bosch or a reproduction 009 clone? If a clone....they are notorious for erratic timing curves
Check/adjust in this order:
Valves while engine is cold to 0.006 per VW specs
Point gap/dwell (If you have electronic 'points replacement' I would be suspect of those modules...could try swapping in points& condenser to rule out the module)
Timing via timing light (30deg BTDC max advance- allow idle timing to fall where it may)
Carb adjust (per your manufactures guidelines)
You could also have a bad condenser (if you run points&condenser) "No stamp" bosch condensers seem to be hit and miss lately. NAPA Echlin and Beru are decent brands.
You may also need to 'balance your dual carbs' or your throttle linkage rod could be out of adjustment. Or perhaps one of the carbs have some clogged passages (?air bypass?). If you haven't worked on the carbs, now may be a good time to really scrutinize them and give them a good refresh if any doubts.
Either way, If you could have a friend rev it and get it to misfire your could use your timing light to look for a 'skip' or pull plug wires off the distributor until you find the wire that you pull that makes the misfire stop. Also check to make sure that your wires aren't cracked or 'leaking' current. If you stick your hand in the engine bay while running and you get all tingly....THATS NOT GOOD...and need plug wires replaced.
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor |
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AlmostHeavenWV_VW
Samba Member
Joined: October 12, 2017
Posts: 1966
Location: WV
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| Posted: Fri Jun 07, 2019 8:34 am Post subject: Re: Engine ground(s) |
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A photo or two of your engine bay could help narrow down issues as well.
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor |
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glutamodo
The Android
Joined: July 13, 2004
Posts: 26323
Location: Douglas, WY
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| Posted: Fri Jun 07, 2019 8:40 am Post subject: Re: Engine ground(s) |
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VW did specify .004" on all short stud engines until near the beginning of model year 1972.
0.006" then became the norm - retroactively applied. I think the extra .002" was a safety factor.
_________________
Andy T.
IMAGE NOTE: It has been noted that Chrome based browsers may have issues in displaying my vast image library, which use non-secure links and are on an FTP server. Images should still be viewable if the link is clicked though.
I do not know how to fix this. All I can say is it all works fine for me with what I use, Firefox.
Last edited by glutamodo on Fri Jun 07, 2019 8:41 am; edited 1 time in total |
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dubsteez79
Samba Member
Joined: November 22, 2017
Posts: 194
Location: star nc
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| Posted: Fri Jun 07, 2019 8:41 am Post subject: Re: Engine ground(s) |
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Thanks for the pics guys. I think i remember seeing the one on the frame horn which would make sense. I believe I will replace it with a new one just because its possible that I cleaned just the outside of the braid with a media blaster. We just restored a 58 case tractor where my dad cleaned its ground strap by blasting and had a no-crank condition as well as intermittent lights. It was hella corroded on the interior of the braiding so we replaced it and everything worked perfect.
Pic of the tractor because im proud of how nice it turned out 
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dubsteez79
Samba Member
Joined: November 22, 2017
Posts: 194
Location: star nc
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| Posted: Fri Jun 07, 2019 8:43 am Post subject: Re: Engine ground(s) |
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Engine bay before new carbs and linkage
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