In which our hero descends upon Renton, WA.

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Ronin10
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In which our hero descends upon Renton, WA.

Post by Ronin10 » Sun Aug 03, 2014 1:32 pm

A little late on the visit report, but as soon as Colin left, family arrived and then off to my son's theater performance (which I drove Greta to).

The 1st was my birthday and so before Colin arrived, I decided to run up to the Starbucks up the street and get my free coffee around 8am. Pulled into the parking lot and lo' and behold, there was the BobD. Got my coffee and chatted a bit with Colin before heading back home to drill out the makeshift rivets holding up my disintegrating and sagging insulation panels in the roof of my engine compartment. I had dropped the engine/transaxle combo the night before to expedite the swapping of the ratty transaxle I'd been laboring around on for the a newly rebuilt unit from Gary's Transaxles.

Shortly after I had removed the old insulation panels, Colin arrived and we chatted for a bit over coffee. I installed the replacement left hand insulation panel while Colin gave my engine a once-over, peeking at the valves and such. We then moved onto a couple hours of oil leak hunting which resulted in swapping out my oil cooler and identifying candidate sources for the leaks. My wife made a run for Subway, we ate and then swapped the transaxles and installed the engine/trans combo. During the clutch adjustment, we found no pedal resistance whatsoever. We both had a bit of an Oh Shit moment, separated the engine from the transaxle and then put in the old release bearing (which was still in good order), reinstalled everything, and voila! correct resistance at the clutch pedal.

About 7pm or so, we had the engine installed and running and we were onto the second major bullet point on my to-do list: identify why the #2 cylinder wasn't contributing (and thus screwing up my idle stability). Did some harness testing, but long story short, bad injector identified by swapping the injector from #2 to #1 and sure enough the problem followed the injector. Swapped it for a spare and we had a successful, albeit "nervous" idle, but stable nonetheless.

At this point, it was nearly 11pm and we agreed to meet for the next day and another 1/2 day session to fully smooth out the idle issues and tick off some other minor to-do items. But first, after Colin departed, I had to get my CV joints installed. That took me until 2am including cleanup. Took a shower, hit the sack, and woke up at 8am to go again.

Colin was prompt as ever, showing up at 9am and we set to some engine tuning. Two bits of illumination came out of this tuning: first, my Webcam 104i camshaft used in the rebuilt engine, seemed to be the likely culprit behind the now less-so, but still "nervous" idle. And second, that my distributor required lubing, idle being a bit lax in recovering down from higher RPMs.

From there, we scratched a few quickie items off the list: swapped my 1971-ish wiper more for a 1978 motor with the correct wiring scheme, got my horn working, and turn signal cancelling.

I do have a bit of homework to do. The oil leak still exists to a lesser extent and there is always more to do that wasn't on the IAC visit list, but overall I'm very happy to have had the visit. I've always felt like an island in the ACVW world and being able to work alongside an experienced veteran was both educational and fun. Probably some of the best money I've invested in Greta. Thanks Colin!
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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glasseye
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Re: In which our hero descends upon Renton, WA.

Post by glasseye » Sun Aug 03, 2014 6:52 pm

Ahhh. He departs, leaving a trail of happy customers in his wake.
"This war will pay for itself."
Paul Wolfowitz, speaking of Iraq.

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Amskeptic
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Re: In which our hero descends upon Renton, WA.

Post by Amskeptic » Sun Aug 03, 2014 9:54 pm

glasseye wrote:Ahhh. He departs, leaving a trail of happy customers in his wake.
I enjoyed that visit. He's a bright one, that Ronin10, the reparte was gentle but sparkling.

I take the blame for the release bearing, as the IAC business liability/reputation bullet points inside my head are supposed to remind me to double-check everything. Fortunately, I had decided to adjust the clutch freeplay very shortly after we installed the engine, so it was a relatively minor setback. But STILL . . .

Anybody note that I am batting 1.000 with faulty Cruzin injectors this summer?
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

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airkooledchris
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Re: In which our hero descends upon Renton, WA.

Post by airkooledchris » Mon Aug 04, 2014 1:52 pm

You mean the 107i camshaft from Webcam right? I wonder what their reasoning was behind the changes they made.
Here are the stats for the 107i modified hydraulic Cam and the specs for the stock hydraulic VW cam (according to them, did VW actually publish those stats themselves?)

Grind:107i
Intake - Exhaust
Valve Lift (Inch): 0.430 - 0.430
Valve Lift (mm): 10.92 - 10.92
Advertised Duration: 255° - 255°
Duration @ 0.050": 225° - 225°
Lobe Center: 108°

VS

Grind: Stock
Intake - Exhaust
Valve Lift (Inch): 0.333 - 0.313
Valve Lift (mm): 8.46 - 7.95
Advertised Duration: 224° - 230°
Duration @ 0.050": 196°
Lobe Center: 108°
1979 California Transporter

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Ronin10
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Re: In which our hero descends upon Renton, WA.

Post by Ronin10 » Mon Aug 04, 2014 2:56 pm

Yes. My mistake, it's the 107i. Not sure why 104i was stuck in my head.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: In which our hero descends upon Renton, WA.

Post by Amskeptic » Tue Aug 05, 2014 6:40 am

Ronin10 wrote:Yes. My mistake, it's the 107i. Not sure why 104i was stuck in my head.
How are your cold starts and cold running behavior?

Did I mention that my bus went to hell in a handbasket right as I got on the 205, yeah well it did, and the Renton commuter types were hyper, too.

So idle vacuum is a new number we need to address with L-Jet engines running aftermarket cams.
Stock appears to be just about 14" mercury.

If it feels like it is running out of gas and it isn't and the points are blacked pitted . . . condensor.
ColinInBoiseIdaho
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

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Ronin10
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Re: In which our hero descends upon Renton, WA.

Post by Ronin10 » Tue Aug 05, 2014 7:01 am

Idle is a bit sluggish on the cold start, but not unreasonable. I sit for a minute or two twiddling on the phone (since I don't have a cigarette to roll) and then off I go. Within a few miles, it's operating as normal. Will keep an eye on it over the next week or so.

Adjusted the stop plate/shifter position last night in an effort to reduce the popping out of 1st and engagement into the various gears. Seems okay so far, but that was only the one test drive. Oil change next weekend and maybe some more investigation into the oil leak.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: In which our hero descends upon Renton, WA.

Post by Amskeptic » Tue Aug 05, 2014 7:20 am

Ronin10 wrote:Idle is a bit sluggish on the cold start, but not unreasonable. I sit for a minute or two twiddling on the phone (since I don't have a cigarette to roll) and then off I go. Within a few miles, it's operating as normal. Will keep an eye on it over the next week or so.

Adjusted the stop plate/shifter position last night in an effort to reduce the popping out of 1st and engagement into the various gears. Seems okay so far, but that was only the one test drive. Oil change next weekend and maybe some more investigation into the oil leak.
*Have you had more instances of 1st gear misbehavior since my little episode?*
If so, inform your transmission rebuilder right away.
Colin :pale:
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

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Ronin10
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Re: In which our hero descends upon Renton, WA.

Post by Ronin10 » Tue Aug 05, 2014 7:41 am

I have had it happen about 4 or 5 times, but then I hadn't adjusted the clamped position of the shifter, which others have said is necessary after a rebuild. Did that last night, no issues on the test drive, but will get more driving in tonight to verify. I left the front mat out so I can play with the adjustment over the week, but will definitely send a note to my builder.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Ronin10
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Re: In which our hero descends upon Renton, WA.

Post by Ronin10 » Thu Aug 21, 2014 8:29 am

Had an e-mail conversation with my transaxle builder, who was very supportive, and continued to play with the stop plate, but couldn't quite adjust away the issue. I cracked the Bentley manual and looked at the transmission install procedure. I followed the adjustment procedure where you loosen the two vertical bolts at the nose of the transaxle, shake the transaxle/engine combo at the heat exchangers and retighten the bolts. That seems to have calmed the popping out of gear. Shifting is still a little clunky going into 1st gear, but I've found a new issue which is demanding more attention.

I took Greta out for her first extended freeway drive after Colin's visit about a week and a half ago. There were a few instances of bucking while in 4th gear, but it was very mild, almost like hitting a small, unseen pothole, but I couldn't figure out a way to repeat the bucking effect and I needed time to ponder.

My pondering led to wondering if this was somehow related to the transaxle swap (unlikely) since it was fresh on my mind, but concluded that it was more likely a cylinder missing. I'm still of that mindset. So the candidates on that front to investigate are air, fuel, and spark. Given that both Colin and I have thoroughly investigated for vacuum leaks, I doubt air issues are present.

On the fuel front, I knew my fuel filter was due for a replacement, so I went ahead and did that last Saturday. I also bought a container of Lucas Deep Cleen Fuel Injection System cleaner and added that to a fresh tank, also on Saturday. Since then, I've driven through about 3/4 of that tank and the problem has become noticeably worse. In fact, drove to and from Seattle last night with about 3 hours of rest in between and the bucking wasn't terribly apparent on the way into the city (4th gear on the freeway), but by the time I was coming home, it was very apparent in 2nd, 3rd, and 4th gears both on the freeway and driving on surface streets, up hills, on flats, while accelerating, cruising, and decelerating. Getting worse with time seems to imply a temperature effect due to the engine heating up.

So with all this in mind, my mind goes to that bad injector we swapped out. Even though I had a poor idle (3 cylinders) and a failing transaxle before Colin's visit, there wasn't any bucking from the cylinders that were working. The injector swap was the only fuel supply change we made to the engine other than tuning the AFM, and I don't see a time/temperature effect being likely by adjusting the black cog. My theory is that the injector we used as a replacement isn't terribly wonderful either and that as the engine heats up the spray pattern/quality/volume degrades.

After this, I think I'm off to investigating the ignition system.

Care to validate or refute my theory? Offer alternatives?
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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asiab3
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Re: In which our hero descends upon Renton, WA.

Post by asiab3 » Thu Aug 21, 2014 10:03 am

Not refuting or validating anything you've said, just hungry for details.

Has your fuel economy changed? Any temp trends that have changed? (Bucking on the highway isn't usually just one cylinder slacking off occasionally. When I had an occasional single cylinder miss, it sounds more like the worlds tiniest rev limiter kicking in once every few seconds. Audible but hardly noticable otherwise. On the other hand, when a friend's TS2 came unplugged and we had an overly rich condition, bucking would be an excellent word to describe it.) I see the bucking gets worse when the engine heats up, and I know it's sometimes a cop-out, but have you tested your setup with a good points/condenser setup? We're all a little inclined to recommend what has worked for us before, aren't we....

...Robbie, with points saving the day in 112* desert crossings:

Image

^ that's what happens when a tick turns into a buck turns into smoke. Turns out the off-brand modules don't like the heat.
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

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Ronin10
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Re: In which our hero descends upon Renton, WA.

Post by Ronin10 » Thu Aug 21, 2014 11:37 am

My knee jerk reaction was to go directly to the ignition system, but what has me wanting to systematically clear the fuel system first is that it was the only thing we really fussed with during Colin's visit. And with the bucking accompanying the injector swap, it seems too likely a culprit to ignore.

That said, I do have a condenser floating around. Not sure about points, but will check that out once I move onto the ignition system. Colin did mention while he was here that he felt my distributor needed some lubrication as the centrifugal weights didn't seem to be retracting quickly enough as my idle would hang on the high end before descending over time to a normal idle.

Now, to address your specific questions and comments...

1st tank of gas after Colin's visit: 17.5 MPG with a mix of city and highway driving. About typical to what I've experienced before.

Temps. Ambient temps have actually been somewhat cooler than typical: upper 70s to low 80s. Typically, we're in the mid- to upper-80s this time of year. Nothing overtly hot though.

I don't have my CHT gauge hooked up so I can't comment on what those temps are at in absolute sense, let alone the more meaningful trend. On the to-do list.

Bucking vs. Ticking. This is definitely a buck. You feel it substantially more than hear it. I see why we all key in on the ignition system as as a buck seems more like several consecutive misses than just one cylinder slipping in an out, which seems like it would be much milder than what I'm experiencing.

This weekend will be a good opportunity to work on it. Hopefully, I'll have more details come Saturday afternoon/evening.

Going in plan for the weekend is to clear the fuel system and maybe move along to ignition system as time allows:
* I've previously addresses or am comfortable with the operation of the fuel pump, fuel pressure regulator, cold start valve, TS2, and TTS so I'm bypassing those for now.
* Test the fuel rail pressure at idle, 50% throttle, and WOT, as well as the transitions between those settings. I tested this earlier this year, but I want to note what I have and how it behaves. For posterity's sake.
* Check air-fuel ratio with my LM2 (assuming I can get it operable, may have a bad O2 sensor). Again, as I want to document where I'm at.
* Pull #1 injector (the one we changed) and verify correct electrical and spray behavior.
* Swap in alternate injector, test spray pattern, and install.
* Test drive to see how this goes.

Any other fuel delivery related items I need to check while I'm at it? If not, then I'll move onto the ignition system.
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: In which our hero descends upon Renton, WA.

Post by Amskeptic » Thu Aug 21, 2014 11:43 am

Ronin10 wrote:bucking while in 4th gear, Getting worse with time
It is a plague, an epidemic. I too, am suffering from bucking. I did points and condensor and fuel filter. Bucking came back. Found a loose #2 wire **where it attaches to the distributor end's brass thingamajiggy**. That was my issue, it may have been caused by my penchant to remove wires from the cap to see what cylinder is not participating . . . . . . :cyclopsani:
Please try an experiment:
IF we mucked with the AFM towards rich, please lean out the mixture screw on top of the AFM a good three or four turns (count so you can get back to zero.
Let us know if the symptoms ceased, reduced, or got worse.
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

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Ronin10
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Re: In which our hero descends upon Renton, WA.

Post by Ronin10 » Fri Aug 22, 2014 10:17 pm

So here's how my evening went...while researching, I read that some people had issue with bucking due to loose connections at the double relay. Checked the connectors and all seemed securely...well, secured.

After that, I performed a fuel rail pressure test. 36 psi at startup, same 5 min later. I then did 10 WOT revs and went immediately to the back of bus: 32 psi. Held throttle at 50% for 30 sec: 32 psi. Shut it down and it held 37 psi for 5 min when I stopped monitoring the fuel pressure. All readings seemed reasonable.

Did notice that the exhaust still smells rich.

So now, I was ready for a test drive. I started it back up and noticed that the idle was kind of loping, rising and falling over a 5-10 second period. Remembered that I hadn't adjusted the mixture screw, I shut down, backed off the mixture screw 4 turns and started things up again. Idle didn't seem to behave differently.

So the test drive..drove about 5 miles to the gas station. Relatively flat road, 50 mph speed limit. No issues en route to the gas station. Upon arrival at the gas station, the idle dropped down to steady RPMs, no rising and falling. *shrugs* Gassed up and jumped on Highway 18 and drove out to I-90. About a 20 minute drive with a 800 foot or so climb over about 3 miles. No issue there so I turned around at I-90 and drove home. I thought I might have felt some mild bucking on the way down the (now) 800 foot descent, but it was hard to distinguish between a mild buck/hitch in the engine operation and the unevenness in the road. Nothing else apparent on the rest of the drive home.

Maybe need some more driving time under my belt before I can call it settled, but looks promising so far.

So the question, why does a richer mixture cause bucking?
Oscar: 1976 Sage Green Bus, Stock Motor, Solid Lifters, Manual Transaxle

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Amskeptic
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Re: In which our hero descends upon Renton, WA.

Post by Amskeptic » Sat Aug 23, 2014 5:28 am

Ronin10 wrote: So the question, why does a richer mixture cause bucking?
Cuz its choking to death?

We need to figure out how to get rich enough under heat-generating loads, yet lean enough for proper no-carbon-build-up running. I usually tighten the spring and move the wiper richer. This gives us richer under load and the spring snaps it leaner under partial throttle. There are mysteries yet.
Must research on my next long highway run . . .
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

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