1976 Bus - Test for AFM? ** It's still bucking!!**

Carbs & F.I.

Moderators: Sluggo, Amskeptic

Post Reply
User avatar
nathan@el
Getting Hooked!
Location: Guilford, Vermont
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by nathan@el » Thu Jun 02, 2011 1:10 pm

I'm glad that you've got it all figured out, finally! I'm dealing with a similarly frustrating bucking issue, and just ordered a TS II from Bus Depot. I'm hoping this will solve the problem. I have a sneaking feeling this is some sort of electrical problem for me.
Orange 1980 Vanagon L Westy
~190,000 miles on body
~20,000 on engine

TrollFromDownBelow
IAC Addict!
Location: Metro Detroit
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by TrollFromDownBelow » Thu Jun 02, 2011 6:40 pm

After my experience, I'm wondering if the problems people have with TS II is really due to poor connections... you pull the old one out, connect the new one which happens to clean the mating surfaces on the electrical connectors, and voila! problem goes away.

I know the part is relatively cheap, but there is a way to test the old one ... can't remember the value but it should have a certain electrical impedance. While you are waiting for the new one, you may want to test it, and while your at it squirt some electrical cleaner on the electrical connections and see if that helps. :king:
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by Amskeptic » Thu Jun 02, 2011 6:53 pm

TrollFromDownBelow wrote:After my experience, I'm wondering if the problems people have with TS II is really due to poor connections... you pull the old one out, connect the new one which happens to clean the mating surfaces on the electrical connectors, and voila! problem goes away.

I know the part is relatively cheap, but there is a way to test the old one ... can't remember the value but it should have a certain electrical impedance. While you are waiting for the new one, you may want to test it, and while your at it squirt some electrical cleaner on the electrical connections and see if that helps. :king:
2,500 ohms at 68* dropping as it gets warmer. Your test of wiring connectors usually occurs as you try to get the ohm reading. Loosen then tighten the sensor in the head after ohms check out to help re-establish the ground path. If it does not check out, your replacement sensor will clean up the ground path as you install it.
:cyclopsani:
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

TrollFromDownBelow
IAC Addict!
Location: Metro Detroit
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by TrollFromDownBelow » Wed Jun 08, 2011 1:42 pm

Okay ... now I really think that I found the problem.... the TSII was loose.... like loose enough I could tap it and hear it rattle around .. not even finger tight. hopefully this is the last post from me on this subject!
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by Amskeptic » Thu Jun 09, 2011 5:11 am

TrollFromDownBelow wrote:Okay ... now I really think that I found the problem.... the TSII was loose.... like loose enough I could tap it and hear it rattle around .. not even finger tight. hopefully this is the last post from me on this subject!
Second-to-last post from you ... we need your Victory Confirmation.
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

TrollFromDownBelow
IAC Addict!
Location: Metro Detroit
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by TrollFromDownBelow » Thu Jun 09, 2011 6:27 am

will provide confirmation after the weekend. I do think the cause of the bucking when I posted this two years ago was fixed when you and i worked on it in sept 09, as the bus ran pretty good last year (2010).
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

TrollFromDownBelow
IAC Addict!
Location: Metro Detroit
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by TrollFromDownBelow » Mon Jun 13, 2011 1:46 pm

Okay - I can now say with confidence that the loose temp sensor was the culprit....as it came loose again (I was overly paranoid about over tightening and stripping the threads in the head), and the symptoms came back with a vengeance! :geek:

Re-tightened with a drop of loctite (hey Colin, at least I didn't use JB Weld :flower: ) after about 150 miles or so of driving around still tight and no symptoms.
1976 VW Bus aka tripod
FI ...not leaky, and not so noisy...and she runs awesome!
hambone wrote: There are those out there with no other aim but to bunch panties. It's like arguing with a pretzel.
::troll2::

User avatar
Xelmon
Sedna of VW lovers
Location: LA or Portland, OR
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by Xelmon » Mon Jun 13, 2011 3:33 pm

Duudee, nice! I was wondering what TS meant... :)

Also, see? See!?! You start to threaten the creature and it goes "Aw shizzle, that ain't gonna fly! Let's actually work!" :D

fiftybuckbunny
I'm New!
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by fiftybuckbunny » Mon Aug 27, 2012 7:05 pm

I also have been fighting with a nasty bucking. Turns out after buying an afm I didn't need and many hours cleaning grounds etc that it was a fuel delivery issue. Put a fuel pressure gauge on it with a hose long enough to get it where you can see it when driving and note the results. My pressure would fall off in 3rd gear at 50 mph and just lose power and start to buck badly. I blew some compressed air into the tank outlet, put a new filter on it and goodbye bucking. I now have a clear filter on it to monitor the amount of rust in it. I'll get a fuel tank someday, but now at least I figured it out.

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: 1976 Bus - Test for AFM? ** It's still bucking!!**

Post by Amskeptic » Wed Aug 29, 2012 7:27 am

fiftybuckbunny wrote:I also have been fighting with a nasty bucking. Turns out after buying an afm I didn't need and many hours cleaning grounds etc that it was a fuel delivery issue. Put a fuel pressure gauge on it with a hose long enough to get it where you can see it when driving and note the results. My pressure would fall off in 3rd gear at 50 mph and just lose power and start to buck badly. I blew some compressed air into the tank outlet, put a new filter on it and goodbye bucking. I now have a clear filter on it to monitor the amount of rust in it. I'll get a fuel tank someday, but now at least I figured it out.
Congratulations. Let us be the forum who proudly tells the world that our classic old VW troubles are usually simple oversights and dumb maintenance chores hitherto overlooked.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

Post Reply