Bucking, lurching leads to no camping and bummed out kids

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Sun Jul 15, 2012 1:13 pm

I opened the AFM cover and moved the wiper to the left and was able to hear the fuel pump engage. So, I guess the pump is not dead. It may not be outputting correctly, but I will need to get a fuel pressure gauge to check that out.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

luftvagon
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by luftvagon » Sun Jul 15, 2012 2:02 pm

Have you done any of the electrical work we suggested?
1981 Volkswagen Vanagon Westfalia - air-cooled Type4 1970cc CV (hydraulic lifters, 42x36 valves, stock cam, microSquirt FI with wasted spark ignition)
1993 Ford F-250 XL LWB Extended Cab 7.3L IDI

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Sun Jul 15, 2012 2:11 pm

Randy in Maine wrote:The TSII is a black wire with a female crimp connection that fits into an off-white plastic connector (with 2 male ends). The other female crimp connector goes into the wiring harness.

You are going to remove the wiring harness connection female end using your needle nose pliers and touch that to a known good ground and see if the bucking goes away.

If it does, you are going to clean all of connections using some sand paper until they are nice and shiny and re-insert them in the cleaned white connector.

Let us know what happens.
AND THE WINNER IS.....

The TSll wire has a female end which is directly connected to the male spade of the wire leading to the harness. As I pulled the two apart, the wiring harness end just crumbled at the male spade connector which was held on by a few measly strands of corroded copper wire. I attached a separate length of wire and grounded it to the firewall. VRROOOM! and off we went with no bucking under full power.

Of course now it makes sense since the problem got worse after I replaced the TSll. The more we disturbed that wire, the worse the connection.

The bad news is that we missed an entire beautiful summer weekend of camping with other VW bus owners over a five minute fix that costed only a few cents.

The good news is that we eventually fixed the bus in under five minutes for only a few cents. We learned a lot of troubleshooting tips and a lot more of how our bus works. My sons were good sports who helped me a lot and enjoyed trying to solve the puzzle as we ruled things out.

Thanks to all who offered suggestions and especially to Randy in Maine who was once again vindicated by the Temp Sensor ll! :cheers:
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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Randy in Maine
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by Randy in Maine » Sun Jul 15, 2012 3:14 pm

Every day we learn somethng about our buses is a good day.

Now go take those kids down for an ice cream in it.
79 VW Bus

luftvagon
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by luftvagon » Sun Jul 15, 2012 4:08 pm

..at least you didnt have to work all weekend...
1981 Volkswagen Vanagon Westfalia - air-cooled Type4 1970cc CV (hydraulic lifters, 42x36 valves, stock cam, microSquirt FI with wasted spark ignition)
1993 Ford F-250 XL LWB Extended Cab 7.3L IDI

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Mon Jul 16, 2012 12:37 pm

OK, I'm back. I finally got the wires hooked back up as yesterday I found out I did not have the proper sized male spade connector.

A milder form of bucking ensued. Mostly at the lower speeds of 1st and 2nd. It was not violent and I could drive through it pretty easily. There were occasional hiccups when cruising in 3rd and 4th. It seemed more prevalent when the engine was colder (it's a pretty warm day here) and almost disappeared once the engine warmed up.

I did not mention previously that I have the spacer attached to the TSll which is outlined by Ratwell here:

http://www.ratwell.com/technical/TempSensorII.html

"A temperature spacer 022 133 079 is available for cars which run well on initial start-up and when fully warm, but have performance problems only during warm-up. This spacer does not affect the resistance values when the engine is cold or when it is fully warm, but it does delay the change in resistance during warm-up, The spacer temporarily insulates the temperature sensor housing from the heat of the cylinder head".

Could this be interfering with the proper signal to the ECU or is the problem still likely in the TS ll connection or harness wire down the line somewhere?

The bus definitely runs 98% better now so I am confident that this solution was correct. I just need to know what to do next to get that extra 2% and eliminate the bucking completely.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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Randy in Maine
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by Randy in Maine » Mon Jul 16, 2012 12:53 pm

So what happens when you remove the spacer?
79 VW Bus

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Mon Jul 16, 2012 1:07 pm

Randy in Maine wrote:So what happens when you remove the spacer?
Darn it, I knew that's what you were going to say. I am really hesitant to pull the sensor. Whoever put the engine together last made it so the tin around that hole is pressing down on the sensor slightly. Once the sensor is removed the tin moves down and blocks the hole almost imperceptibly. There does not seem to be a way to pry the tin out of the way. A friend who stopped by noticed it and was able to somehow pull up on the tin with his right hand while inserting the sensor with his left. I think it took him/us almost an hour. He is a lot stronger than me so I am not sure if I can repeat it.

The bus mostly behaved well for years with that spacer in place. That's why I used it again when I replaced the old sensor.

I guess I will have to figure out a way to get that TS ll in and out without that tin messing things up every time.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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Randy in Maine
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by Randy in Maine » Mon Jul 16, 2012 1:48 pm

Mr. Dremel tool is your friend here along with a srewdriver (to lift the tinwork a little and to allow you to remove a bit of engine tin to allow better access/better fit for the TSII).
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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Mon Jul 16, 2012 2:08 pm

It is such a tight space I'm not sure about getting a screwdriver down there while trying to get enough leverage. Also a bit scared that the Dremel could damage the threads to the hole if I can even get it the space as well. But I will give it a try.

BTW would a 13mm ratcheting box end wrench (I don't have one) work better for removal and replacement of the TS ll vs. the stuff the wire in a 13mm deep socket (I don't have one of those either) method? Since I need to buy one or the other I think the box end would be more versatile,
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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SlowLane
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by SlowLane » Mon Jul 16, 2012 3:06 pm

aopisa wrote:BTW would a 13mm ratcheting box end wrench (I don't have one) work better for removal and replacement of the TS ll vs. the stuff the wire in a 13mm deep socket (I don't have one of those either) method? Since I need to buy one or the other I think the box end would be more versatile,
Ratcheting box-ends are indeed wonderful tools, but they don't solve every problem. I found that for the TS-II sensor, the fact that the box end can only swing in one plane limited its usefulness, because other stuff in the vicinity limited the degree to which it could swing. Perhaps a flex-head ratcheting box-end would be more useful there.

Sockets of course, give you the option of using universal joints and extensions, if you have the room to use them.

Best to have both options. You can never have too many tools. :wink: (yeah, my wife doesn't buy it either...)
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by Amskeptic » Fri Jul 20, 2012 9:51 am

aopisa wrote:It is such a tight space I'm not sure about getting a screwdriver down there while trying to get enough leverage. Also a bit scared that the Dremel could damage the threads to the hole if I can even get it the space as well. But I will give it a try.

BTW would a 13mm ratcheting box end wrench (I don't have one) work better for removal and replacement of the TS ll vs. the stuff the wire in a 13mm deep socket (I don't have one of those either) method? Since I need to buy one or the other I think the box end would be more versatile,
Leave it alone. Have fun with other experiments.
A) Richen the mixture screw on the AFM One Whole Turn Clockwise.
(does it help your little hiccups?)
B) Lean the mixture screw on the AFM One Whole Turn Counterclockwise then another! for a Net One Turn Counterclockwise from initial point.
(does this help your little hiccup?)

One or the other of the above should help, and one or the other of the above should make it worse.
Let us know.
IF A helps, leave the washer on the TS II.
IF B helps, remove the washer.
If you can't tell, put everything back to initial point, leave it well enough alone, and we will fix the problem later when we tune it.
Colin :blackeye:
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 104,650 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Fri Jul 20, 2012 10:00 am

I was starting to think AFM because it seems to now be less random. I can almost predict when it is going to do it. It also seems to be idling a little lower. Can it wait until September? I think so as to now it seems to be more of an annoyance that an undriveable condition. I wanted to do some road tripping before you arrive. I would rather drive it with some confidence that this is not going to hinder traveling some distances. Maybe something else unknown will, but Idied not want to just go driving off ignoring this issue until it comes back to bite me again.

Have to brush up on the concise AFM lesson. I will experiment tomorrow and report back.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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aopisa
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by aopisa » Sun Jul 22, 2012 5:36 am

I was going to try experimenting with the mixture screw yesterday, but first had to run an errand in town. The first few minutes I was remarking how great the engine was running. A few minutes later, the bucking and lurching returned with a vengeance. I lurched into a parking lot. The idle was so low that the bus kept stalling.

After getting back home. I tried adjusting the mixture screw with no results that helped the problem.

I also decided to disconnect the TS ll and ground the wire leading to the ECU since that seemed to be the condition that gave the best results, just to confirm that I could make it run smoothly again. This time there was no change. I could barely make it a few yards past the house. So, maybe I was too hasty in originally declaring that this was the problem.

Now I am stumped.

EDIT: The latest condition is now the bus does not really want to start. Once I get it turned over, I have to give it quite a bit of gas while it idles roughly. After it warms up a bit, it seems to smooth out a little, but I still can't drive it without it lurching, cutting out and stalling.
1977 Westy 2.0L F.I.

Flow with whatever may happen and let your mind be free. Stay centered by accepting whatever you are doing. This is the ultimate. - Chuang Tzu

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SlowLane
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Re: Bucking, lurching leads to no camping and bummed out kid

Post by SlowLane » Sun Jul 22, 2012 8:19 pm

Not to flog a dead horse, but ... did you check the AAR elbow? Inspect the S-boot for cracks? Check the seal of the valve cover gaskets?

Are you using points, or do you have a pointless ignition?
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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