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IAC Indiana review and follow-up

Posted: Fri Jun 24, 2016 9:34 am
by Squeebles
Colin was here last Tuesday for his second visit, a year after the first. My bus is a 77 Westy with FI.

Primary order of business was a tune-up, then clutch adjust. There was also a matter of oil pressure light that flickers when idling after long drives (i.e. oil is hot and thin). Oil pressure gauge revealed that it was within spec, although on the low side. This is a legacy of a rebuild by local, highly-recommended builders that did a terrible job. I wrote about it here last year, but long story short - the lesson, as always, is do it yourself. It will take longer and be difficult at times, but not as difficult as dealing with problems that you have to first diagnose and then fix.

After clutch adjust (I had way too much free play), took it for a drive. Colin immediately noticed some clutch chatter. After talking about the causes (oil contamination, damaged clutch) we figured out that since the bell housing was bone dry on the outside, the clutch must not be properly straight/plumb. After Colin quizzed me about the last time I installed the engine, during which he asked me if the engine/trans mating surfaces ever looked like /\, instead of ll (answer was yes), he determined I likely caused the damage to the then-new clutch assembly. So a new one will go in at some point in the next little while. until then, driving very gently minimizes the problem.

That brings us to this weekend, a camping trip to southern Indiana. Bus ran fine. Oil light was flickering at times, which I found irritating and slightly stressful but I took comfort in knowing that the pressure was above minimums. At a stop light close to home, I let the clutch out a little too quickly, got some chatter and a stall. Tried to restart a few times, no luck. I got out, did a quick check in the engine compartment, everything seemed to be connected correctly. Since I had three others with me, including two hungry kids that had to pee, I arranged for a tow truck.

My ignorant and slightly not-thinking-straight brain was assuming the worst, that something to do with the low oil pressure and hot conditions had caused the engine to overheat and stall, never to be started again until disassembly and reassembly with proper oil pressure! PM to Colin assured me I was being stupid, and that the problem was likely to be much simpler and a result of something subtle disconnecting with a chatter/lurching start.

Fast forward to home - I had more time to look things over. Got the bus started but it was very reluctant and ran unevenly. It seemed like a fuel issue. But no chance of taking it on the road like this. I checked every connection, every wire, every hose, every plug. Disconnected everything connectable and re-connected. No improvement. Turned key to on position. Heard fuel pump running until after engine start. This should not be happening. Went to AFM, opened it up. Lo and behold, the wiper arm was all the to the right, past the small copper contact it should rest upon before engine start. The silver screw retaining it, the one that is usually topped with a gob of something or other, was not sufficiently tight. And it had sprung completely loose during my final lurching start. Re-adjust and it fired right up. Running fine again.

Hopefully this long read has some use and some lessons here. It did for me: 1) think before you panic, 2) the solutions to most problems are simple ones, and 3) Colin is very often (can't say always!) right.

Re: IAC Indiana review and follow-up

Posted: Fri Jun 24, 2016 4:57 pm
by asiab3
Wow, excellent detective work in the AFM! I've always pondered the spatial relationships that VW had to think about when placing the AFM in the engine compartment. Can't cant it one way or another too far, or it will give false readings due to gravity, or due to hard cornering, or due to SUDDEN STARTS AND STOPS. :pirate:

Was the silver screw you speak of the "static" adjustment locking screw on the wiper? If so, will you ned to retune your AFM from the jolt? Also, does the fuel pump contact points in the AFM pry themselves open when the flap arm gets bunked like yours did? I don't have a spare AFM with me anymore to inspect.

Thanks for the write up!
Robbie

Re: IAC Indiana review and follow-up

Posted: Sat Jun 25, 2016 5:30 am
by Amskeptic
asiab3 wrote:Wow, excellent detective work in the AFM! I've always pondered the spatial relationships that VW had to think about when placing the AFM in the engine compartment. Can't cant it one way or another too far, or it will give false readings due to gravity, or due to hard cornering, or due to SUDDEN STARTS AND STOPS. :pirate:

Was the silver screw you speak of the "static" adjustment locking screw on the wiper? If so, will you ned to retune your AFM from the jolt? Also, does the fuel pump contact points in the AFM pry themselves open when the flap arm gets bunked like yours did? I don't have a spare AFM with me anymore to inspect.

Thanks for the write up!
Robbie
Squeebles! Well done. Here is a photograph of your oil pressure on the fresh rebuild. Barely at 28 psi at 2,500 rpm.
Where does the oil pressure go from here? Right . . . :

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Here is our witness, Ruby. Ruby saw it all:

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Here is our customer, pondering the whys and wherefores of oil pressure and clutch chatter:

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Me? I look at this and say, onwards to the next challenge and the next challenge:

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So, my question is, did we, you and I, Squeebles, did we adjust the AFM this go around? It is difficult for me to imagine that the below -
At a stop light close to home, I let the clutch out a little too quickly, got some chatter and a stall.

-might have dislodged the wiper? The silicone applied from the AFM factory is an anti-tamper glob, not a Known To Loosen Preventative.

Either way, you have diagnosed, repaired, and restored autonomous movement to your Volkswagen. And we again diagnosed, prescribed repairs, and restored a little perspective regarding greasy corporate interference in the realm of research and education, and perhaps a little hope to the State Of The Nation.

Speaking of the state of the nation, what is with the state of the roads?

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The buckling and heaving and crumbling roadways has been a pox on my spirit since Pennsylvania. We can do better, and we refuse to accept a little hike in the gas tax with these record low gas prices? More importantly, can we actually get the taxes to the roadways and not into some self-important little bureaucratic fiefdom that spends its days justifying its own salary, and dreaming up ways to demand more funds for less work (I'm talking to YOU, Port Authority of New York and New Jersey)?
Just asking.

Beautiful days are still free. That Squeebles June 14th visit was bookmarked by the andrewtf calls, and I had to hoof it back from Indiana to Illinois through this gorgeous countryside:

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We was hoofin' it too, me n NaranjaWesty, we had to get to Illinois doin 60 through this:

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But this had other plans:

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And I heard brakes screeching, and I saw slowing, and I enjoyed a moving Urban Art Show:

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The moving Urban Art Show came to a complete stop only fifteen cars shy of clearing the road I was on. I hopped out and chatted with the car behind me.
"How long do you normally have to wait?"
"Could be fifteen minutes, could be three hours, once had an overnight."
"I can't afford that, how can I get around the train further up or down?"
"Well, we were just trying to get the baby to sleep, so we came across the track and had just turned around down there to go home when the crossing gate came down. How do we get home honey?"

I spied a wizened old German-looking farmer in his yard with a rake.
"How do we clear this train?"
"That is a fine looking Volkswagen, did you restore it?"
"No, I just drive it. How can we cross the tracks around here?"
"My son would love to see that thing. He's in Colorado."
"Perhaps you can book him a flight and he can come see it RIGHT HERE, is there a way across the tracks further on down?"
"Well that depends on how long the train is, doesn't it? Does that thing have one of those tops that goes up?"
"I can see the end of the train."
"No road that way, what do you get for gas mileage?"
"Seventeen, eighteen, does this road hit another road that goes the other way?"
"You mean into town? The train is probably blocking that crossing too, it's a long one, I been watching it go by for a while now. Don't know why it stopped, but they can stop for days. You could camp in my driveway."
"Thanks, but I need to get to Illinois."
The Baby Soother SUV pulled a quiet u-turn and drove back up from whence we came, I did the same. Found my first road to "the other way" and saw the engine almost a mile up the tracks just sitting there. He had a red light. Must be an oncoming train. Found a road that looked like it would cross the track and hoofed towards the crossing. Thwarted at the last second by crossing lights and and bells , but at least this train was hoofin it to Illinois, too.

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Re: IAC Indiana review and follow-up

Posted: Sat Jun 25, 2016 2:58 pm
by Jivermo
That boxcar being...I'll bet if you had sat there awhile longer, he would have turned his head to gaze at Naranja, and you. These things happen.

Re: IAC Indiana review and follow-up

Posted: Sun Jun 26, 2016 6:09 am
by Squeebles
Some answers to questions:

asiab: Yes, it was the static adjustment screw that was loose, and I did have to re-adjust the AFM, did it using the handy article on this site and after being beside Colin doing it a few days before helped. The contact for the fuel pump looked fine, I think the wiper under spring pressure just whipped right by it and behind it and came to rest at the point farthest to the right and there it sat.

amskeptic: you and I did do AFM adjustment that day. It seems odd to me too that bumps and lurches would dislodge it, but nevertheless that was the case. I had not opened it up in between and that screw was not at all tight when I got in there. One of those moments when you know you have found a problem. When it fired right up, it was confirmed.

Re: IAC Indiana review and follow-up

Posted: Mon Jun 27, 2016 6:53 am
by Amskeptic
Squeebles wrote:Some answers to questions:

asiab:
Yes, it was the static adjustment screw that was loose, and I did have to re-adjust the AFM, did it using the handy article on this site and after being beside Colin doing it a few days before helped. The contact for the fuel pump looked fine, I think the wiper under spring pressure just whipped right by it and behind it and came to rest at the point farthest to the right and there it sat.

Amskeptic:
you and I did do AFM adjustment that day. It seems odd to me too that bumps and lurches would dislodge it, but nevertheless that was the case. I had not opened it up in between and that screw was not at all tight when I got in there. One of those moments when you know you have found a problem. When it fired right up, it was confirmed.
Emma and Sven had something similar happen to them outside Fort Collins. Their wiper got stuck at full rich.
I will send Free Tow coupons with all of my 2016 Holiday Greetings cards . . .

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Re: IAC Indiana review and follow-up

Posted: Mon Jun 27, 2016 7:16 am
by Squeebles
No worries SantaColin, insurance co. paid for the tow! It was a good learning experience to plow through all those possible causes, and I'm happy all is well now. Safe travails!

Re: IAC Indiana review and follow-up

Posted: Fri Oct 14, 2016 10:14 am
by Squeebles
At Colin's summer visit, we found a few issues that needed attention. Last week I dropped the engine and took a run at all of them. Here is a list:
  • - rechecked endplay due to flickering oil pressure when hot idling. It was over spec slightly, at 0.006". Purchased new shim to get it within spec at 0.004".
    - remove and re-install oil pump. It had been leaking, installed poorly by previous engine builder.
    - removed and replace clutch and driveplate. Clutch chatter was likely due to a clutch that was damaged during a previous engine R+R. Colin pointed out this can happen if the engine/transmission don't align properly like l l, instead of / \ during re-assembly. I think I might have done this, this one was on me.
    - removed and re-installed leaky pushrod tubes, they were put in sloppily with loads of RTV by previous engine builder
So last night put it all back together. Tried to start and have a strange, new symptom. The engine turns over, but it sounds higher-pitched that usual. Like the starter is working harder than it needs to or something is binding. Engine starts to fire every few cranks, but it will not start. I have plenty of fresh fuel in the tank. I have tried the gas in the S-boot, still no change.

What would cause this? I don't think anything on my list above would lead to this symptom.

My next move is to recheck the starter for proper installation. I have dropped and re-installed the engine at least 6-8 times but never ran into this before. Any thoughts appreciated!

Re: IAC Indiana review and follow-up

Posted: Fri Oct 14, 2016 5:45 pm
by Amskeptic
Squeebles wrote: The engine turns over, but it sounds higher-pitched that usual.
What would cause this? I don't think anything on my list above would lead to this symptom.

My next move is to recheck the starter for proper installation.
Begin your diagnostics with a hand-turning of the engine using a wrench on the alternator nut.
You need to determine if:
a) the engine has unusual resistance to turning

... if unusual resistance, DO NOT CONTINUE, we suspect a botched endplay adjustment!
... if it rotates easily, can you feel a little endplay?

b) there are any weird noises in the bell housing

Before removing the starter, loosen the upper 17mm nut and the lower starter nut and wriggle the starter in the hole, see if it can rotate just a bitty bit in the bell housing flange before you re-secure the upper and lower nuts.
c) does the starter engage more quietly now?
Colin

Re: IAC Indiana review and follow-up

Posted: Fri Oct 14, 2016 6:31 pm
by Squeebles
The answer is most certainly: a) unusual resistance to turning.

Not sure what I did wrong though... followed the Bentley procedure and purchased and installed one new shim, replacing a thinner one. Checked endplay afterwards and it was within spec.

Re: IAC Indiana review and follow-up

Posted: Fri Oct 14, 2016 10:20 pm
by kreemoweet
Squeebles wrote: . . . followed the Bentley procedure . . .
That procedure assumes there is ZERO movement of the front bearing in the case. If you correct for excessive "endplay" that is only excessive
because of bearing movement, you can put a bind on the crank. Did you determine there was no bearing-to-case slop involved?

Re: IAC Indiana review and follow-up

Posted: Sat Oct 15, 2016 7:00 am
by Squeebles
kreemoweet wrote:
Squeebles wrote: . . . followed the Bentley procedure . . .
That procedure assumes there is ZERO movement of the front bearing in the case. If you correct for excessive "endplay" that is only excessive
because of bearing movement, you can put a bind on the crank. Did you determine there was no bearing-to-case slop involved?

No. That actually had not occurred to me. So, once I get it out and access to the shims again, what would I do differently and what clearance would I aim for?

Re: IAC Indiana review and follow-up

Posted: Sat Oct 15, 2016 6:08 pm
by Amskeptic
Squeebles wrote:
kreemoweet wrote:
Squeebles wrote: . . . followed the Bentley procedure . . .
That procedure assumes there is ZERO movement of the front bearing in the case. If you correct for excessive "endplay" that is only excessive
because of bearing movement, you can put a bind on the crank. Did you determine there was no bearing-to-case slop involved?

No. That actually had not occurred to me. So, once I get it out and access to the shims again, what would I do differently and what clearance would I aim for?
We talked about this. Your engine has already been disassembled and corrected once by the shop. Remember the .030" endplay of last summer? That is when we discussed a main bearing loose in its saddle. So what was the correction by the shop? And why are we even dealing with endplay again? Endplay reduction is NOT the solutiuon for low oil pressure EXCEPT when you have .030" endplay or some horrendous number. Please feel free to run ideas past me in PM beforehand.

We are the ragged edge here, with too many variables rushing upon us.

To test for bearing movement in the case (why on Earth would we have to with a fresh rebuild?):

Install four shims. Tighten flywheel only to 50 ft/lbs (all five bolts cross-tightened incrementially) .
Check for any longitudinal movement at the fan pulley end only, using a dial indicator at the flywheel end.
Understand that you can ruin the engine if you screw up. Thank-you.

Now then. What is the end play with four shims? Be prepared to test and test again and be prepared for fractional movement between the marks on your dial indicator. Once you have your number, disassemble and use only three shims.

Merely add the above number to your selected endplay. If you read .001" your minimum allowable endplay of .00275" is now .00375"
If you read .001" plus a good half increment, your minimum endplay is .00275 + .0015 for a total of .0039" aka .004"

If you are nervous, make it a generous .004"- .005". Be careful! New o ring in flywheel! Check for rotation throughout!
Colin

Re: IAC Indiana review and follow-up

Posted: Sun Oct 16, 2016 3:23 pm
by Squeebles
OK, will do these things and report back here. Thanks for the info.