77 Westy high rpm hesitation

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GreenWesty83
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77 Westy high rpm hesitation

Post by GreenWesty83 » Tue Apr 23, 2019 12:02 pm

I got my 77 Westy ready for a good road trip last spring. Did all the usual spring maintenance, plugs, points and condenser, oil and filter, air filter. And with a little of Colin’s insight and awesome write up, I finally tackled the adjustment of the hydraulic lifters. She ran great for the first leg (150 miles) of the trip. Right as we got to the camping area and turned off highway I noticed a small “blip” or hesitation accelerating from 2nd. But made it with no issues to camping area where were we parked for 3 days.
On return trip she ran fine off the bat. No noticeable issues for about 70 miles. Then upon a steep hill climb I got some VERY serious chugging. At the higher rpms of all gears while going up hill. Like almost stalling bad. Barely made it up hill. Had to keep it in first. I pulled over and replaced fuel filter “only thing I failed to do during tuneup”. That seemed to work ok. Made it home on highway alright. But still had hesitation at higher rpms in 4th. Had to feather the pedal keeping it around 50/55.
So now. I replaced coil (BusDepot) and have put in Pertronix. As it sits now I can take her out and drive her about 5-10 minutes perfectly. Has power and runs amazing. Accelerates wonderfully. Then when she warms up the hesitation starts again.
I’m wondering if a vacuum leak would cause an issue like this? About two years ago I replaced all the vacuum hoses, connections and S boot. I did a smoke test on it and found a small smoke leak from the seal around the throttle flap shaft in the throttle body. Could a leak there cause this issue?
What about sediment in the fuel tank? Filters seem pretty clean.
Hoping someone can give me some starting points and what to look for. I will be diligent with my findings
Thanks guys!
1977 Sage Westy
1968 Blue Bug

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Amskeptic
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Re: 77 Westy high rpm hesitation

Post by Amskeptic » Tue Apr 23, 2019 8:42 pm

GreenWesty83 wrote:
Tue Apr 23, 2019 12:02 pm
I got my 77 Westy ready for a good road trip last spring.

replaced fuel filter “only thing I failed to do during tuneup”. Had to feather the pedal keeping it around 50/55.
replaced coil (BusDepot) and have put in Pertronix.
when she warms up the hesitation starts again.
I’m wondering if a vacuum leak would cause an issue like this?
What about sediment in the fuel tank?
Vacuum leak would be less sensitive to temperature and more prone to being full time.

Experiment:
a) when engine is still mostly cool at idle, take off the AFM black plastic cap and move little wiper thing counter-clockwise about an eighth of an inch. Idle go up or down or imperceptible?

b) when engine is fully warmed up, repeat above test. Any different?

c) after you do the test, check security of TS 2 in the cylinder head at #3. Not stupid tight but snug.

d) Check also the brown wire grounds at double relay on firewall. Make sure that the screw is secure but not stupid, it will strip readily if you get too tough on it.
Colin
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

GreenWesty83
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Re: 77 Westy high rpm hesitation

Post by GreenWesty83 » Thu Apr 25, 2019 9:45 am

Excellent! I am going to try that experiment this weekend. Trying to juggle VW maintenance as well as springification of the yard! As soon as I run test I will post results. Thanks!
1977 Sage Westy
1968 Blue Bug

GreenWesty83
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Re: 77 Westy high rpm hesitation

Post by GreenWesty83 » Sun May 19, 2019 5:36 pm

Ok. Update. So I started with the easiest thing on the list when I had a quick minute and looked at the grounds on firewall. Got excited when they were slightly loose! Redid ring terminal and tightened screw (not crazy tight) and jumped in for a drive. No dice. Still has the hesitation issue. I will try to get the AFM test done this week or long weekend. However, I did take a picture of the AFM. I noticed the tracking on the black strip. I have read something about this issue before. Is this in need of a replacement? Let me know. I will post picture from my desktop. To large for phone apparently. Thanks!
1977 Sage Westy
1968 Blue Bug

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asiab3
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Re: 77 Westy high rpm hesitation

Post by asiab3 » Sun May 19, 2019 7:36 pm

Please post a picture as you continue with the other tests. Many AFMs are blamed for other issues. The two tracks on the wiper board are redundant; either will work, so an imperfection on one is not the end of the world.

Robbie
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

GreenWesty83
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Re: 77 Westy high rpm hesitation

Post by GreenWesty83 » Tue May 21, 2019 7:23 pm

AFM1 sml.jpg
AFM1 sml.jpg (312.75 KiB) Viewed 978 times
1977 Sage Westy
1968 Blue Bug

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Amskeptic
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Re: 77 Westy high rpm hesitation

Post by Amskeptic » Wed May 22, 2019 8:03 am

GreenWesty83 wrote:
Tue May 21, 2019 7:23 pm
AFM1 sml.jpg

Those look pretty nasty!

Try to loosen the board and move it 1/2mm somewhere else than where it is now. Then look closely to see if the contacts miss the white-out.
Colin
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

GreenWesty83
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Re: 77 Westy high rpm hesitation

Post by GreenWesty83 » Wed May 22, 2019 9:50 am

So those tracks or lines in the black strip are not good correct? And moving it down would allow the contact points to touch the black strip in a different location?

If so, could this be the cause of my issue?
1977 Sage Westy
1968 Blue Bug

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vwlover77
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Re: 77 Westy high rpm hesitation

Post by vwlover77 » Wed May 22, 2019 5:02 pm

GreenWesty83 wrote:
Wed May 22, 2019 9:50 am
So those tracks or lines in the black strip are not good correct?
The lines are normal, BUT, they appear to be white toward the bottom of the photo. Is that actually the case, or is it just reflection from the camera flash or work light?

If the lines are black, no problem. BUT, if the black track is worn through to the white substrate below, then yes, that is very likely to be the cause of your issue.
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

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Re: 77 Westy high rpm hesitation

Post by GreenWesty83 » Wed May 22, 2019 5:21 pm

I will check closer tonight when I get home.
1977 Sage Westy
1968 Blue Bug

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satchmo
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Re: 77 Westy high rpm hesitation

Post by satchmo » Wed May 22, 2019 8:49 pm

I think the tracks on the board look okay - it is just the way the light is reflected.

However, there is a lot of dust around the AFM (look at the connector plug). Take a q-tip with a little contact cleaner and wipe the board along the track. Maybe slip a tiny sheet of notebook paper soaked with contact cleaner under the contacts and make sure they are clean as well. Alcohol will work if you don't have contact cleaner.

The screws that hold the wiper board down are very hard to remove and you are more likely to strip the screws than to get the board to move. I wouldn't try to remove the screws if your wiper board tracks look good.

See this: https://www.thesamba.com/vw/forum/viewt ... iper+board

I see you checked the ground wires. Also check the contact of every wire/connector in the double relay block. Sometimes a wire connector gets pushed out when the relays are plugged in and doesn't make a secure connection there, leading to all kinds of cutting out, missing, chugging, etc.

Satchmo
By three methods we may learn wisdom:
First, by reflection, which is noblest;
second, by immitation, which is easiest;
and third, by experience, which is bitterest. -Confucius

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bradleygt
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Re: 77 Westy high rpm hesitation

Post by bradleygt » Thu May 23, 2019 4:25 am

ts ii bad?
it's a bay! '78 FI 2L Deluxe Campmobile

GreenWesty83
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Re: 77 Westy high rpm hesitation

Post by GreenWesty83 » Thu May 23, 2019 6:52 am

I’ve tried 2 different TS 2. One was a spare I had though. Thought about just ordering a new one to be sure being that they’re not expensive.
1977 Sage Westy
1968 Blue Bug

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vwlover77
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Re: 77 Westy high rpm hesitation

Post by vwlover77 » Thu May 23, 2019 9:35 am

You can also remove the TS-2 from the variables. After the engine is good and warm, just ground the wire. The TS-2 resistance drops to 0 when hot. Still having the problem? Then it’s not the TS-2 (although it could be the wiring to it).
Don

---------------------------
78 Westy
71 Super Beetle Convertible Autostick

"When we let our compassion go, we let go of whatever claim we have to the divine." - Bruce Springsteen

GreenWesty83
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Re: 77 Westy high rpm hesitation

Post by GreenWesty83 » Fri May 24, 2019 5:15 pm

vwlover77 wrote:
Thu May 23, 2019 9:35 am
You can also remove the TS-2 from the variables. After the engine is good and warm, just ground the wire. The TS-2 resistance drops to 0 when hot. Still having the problem? Then it’s not the TS-2 (although it could be the wiring to it).
So I’m going to ask the ignorant question. Mainly in the name of not damaging my bus. But how would I safely ground the sensor? Could I make a little inline jumper to plug it into a ground? Or unplug the sensor and plug in the wire to ground? Please advise!
1977 Sage Westy
1968 Blue Bug

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