TheSamba.com :: View topic - Sputter, and stall (resolved). Formerly high fuel pressure.

Mon Aug 29, 2011 3:17 pm

So, just closing off this thread for the benefit of anyone who does a search oneday and wants to know the fix. I am still shocked at how few people actually bother to post their fix after bugging all the good hearted Samba folk for advice. Anyway, the issue was:

A failed hall sender in the VW electronic ignition in my wife's crappy dual vacuum 009 distributor (sorry, just my bias coming through again). We are switching back to the stock single vacuum unit (205P) with points, and I have already re-plumbed the vacuum system back to stock. Thanks very much to Busdaddy for loaning me a distributor to use for test purposes and allow me to investigate my hunch. Tina is ecstatic. She better be, 'cuz during the diagnosis process I did the following as well:

Adjusted valves
New German Supply fuel line kit throughout
New CSV to replace the defective old one
New injector seals and donuts
New TS2
New vacuum lines throughout
New valve cover gaskets
FI grounds cleaned; tranny ground cleaned
New FPR
Automatic tranny drain, filter, and new ATF
New fuel filter
And a myriad of other things tested and checked okay

Mon Aug 29, 2011 4:02 pm

Westfabulous wrote:
Adjusted valves
New German Supply fuel line kit throughout
New CSV to replace the defective old one
New injector seals and donuts
New TS2
New vacuum lines throughout
New valve cover gaskets
FI grounds cleaned; tranny ground cleaned
New FPR
Automatic tranny drain, filter, and new ATF
New fuel filter
And a myriad of other things tested and checked okay
All stuff you needed to do anyways, this just forced your hand on some of them. :P
Congratulations on beating the demon, and thanks for posting the cause.

Mon Aug 29, 2011 4:29 pm

busdaddy wrote: Westfabulous wrote:
Adjusted valves
New German Supply fuel line kit throughout
New CSV to replace the defective old one
New injector seals and donuts
New TS2
New vacuum lines throughout
New valve cover gaskets
FI grounds cleaned; tranny ground cleaned
New FPR
Automatic tranny drain, filter, and new ATF
New fuel filter
And a myriad of other things tested and checked okay
All stuff you needed to do anyways, this just forced your hand on some of them. :P
Congratulations on beating the demon, and thanks for posting the cause.

Sure it isn't the AAR fooling you ?????

Glad you got it fixed. FYI - mine acted up cold last time I took it out. Was a leaky valve cover gasket from an adjustment the night before.

Mon Aug 29, 2011 4:57 pm

SGKent wrote: Sure it isn't the AAR fooling you ?????
:P ,betcha that was the very first thing he checked :wink:

Mon Aug 29, 2011 4:58 pm

SGKent wrote: Sure it isn't the AAR fooling you ?????

Well, let's put it his way. If there are future issues, it could only be: the throttle body gasket, the intake runner hoses, or the AAR, and I always like the AAR as my first choice. :wink:

Mon Aug 29, 2011 4:59 pm

busdaddy wrote: SGKent wrote: Sure it isn't the AAR fooling you ?????
:P ,betcha that was the very first thing he checked :wink:

Surprisingly not, this time, but normally it is.....I'm gonna have to come up with a new pet repair...hmmmm, maybe it'll be: "Checked your 009?" :P

Mon Aug 29, 2011 6:45 pm

Westfabulous wrote: busdaddy wrote: SGKent wrote: Sure it isn't the AAR fooling you ?????
:P ,betcha that was the very first thing he checked :wink:

Surprisingly not, this time, but normally it is.....I'm gonna have to come up with a new pet repair...hmmmm, maybe it'll be: "Checked your 009?" :P

I don't own an 009. Try again. You've used up one guess. :)

Mon Aug 29, 2011 8:21 pm

SGKent wrote: Westfabulous wrote: busdaddy wrote: SGKent wrote: Sure it isn't the AAR fooling you ?????
:P ,betcha that was the very first thing he checked :wink:

Surprisingly not, this time, but normally it is.....I'm gonna have to come up with a new pet repair...hmmmm, maybe it'll be: "Checked your 009?" :P

I don't own an 009. Try again. You've used up one guess. :)

Hmmm, you look like a 205P guy to me Steve.

Sat May 05, 2012 10:36 pm

I thought I would re-open this and close it off once and for all in case some other poor schmuck is suffering from the same issues that Mrs Westfabulous had been suffering from with her bus.

I thought we had it licked last year, but after 6 months of sitting idle, we started up her bus, and the sputtering was back. The exhaust smelled like goat piss, and the bus was backfiring and acting like it was in death throws. Took it for a ride with the engine hatch open and listened to, and felt the machine. It ran beautifully at freeway speeds, but at the lower end of the RPM range, it ran like a turtle with hemorrhoids. Then I realized, it was probably the AFM sweeper field worn out, given the very specific RPM at which the sputtering and backfiring occurred.

So, since my bus is undergoing a refresh, and my AFM was already out, I slapped it into Mrs Westfab's bus, and voila......perfection. I spent nearly a year tweaking that AFM to precision (thanks Colin), and it ended up being perfectly set-up for her bus as well. Problem gone. Sure enough, her sweeper field had deep white tracks at the low RPM end.

I have 3 spare AFM's, so I am going to swap one in tomorrow, and take mine back. Hers was a 7 pin 018 (late '76), and mine (the one I swapped in) is a 7 pin 020, but they seem highly compatible so far. I'll keep my eyes open for a used 018, but for now we are good.

In spite of everything that was done to this bus, most of which was just good maintenance, and done for that purpose, the culprit ended up being a worn out sweeper field in the AFM. For anyone dealing with a similar scenario, this presented as an ignition problem, and perhaps a lean running problem (ie: vacuum leak), but the raunchy exhaust and the specific RPM range for the sputtering issue, ultimately led to the AFM.

She purrs now, and as they say: a happy wife means a happy life. She's happy, and so am I. :)

Sun May 06, 2012 3:38 pm

Thanks for the post. Which inspired me to take a gander at the buses afm, and subsequently fix its subtle miss issue.
http://www.thesamba.com/vw/forum/viewtopic.php?p=6024034#6024034