Chasing issues.

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ruckman101
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Chasing issues.

Post by ruckman101 » Mon Jun 04, 2018 6:28 pm

1970 VW Riviera Pop-top Camper, stock 1600 sp, Bertha.

Background
So the engine has never been that happy after I replaced the re-worked heads that the valves had begun dropping in with new heads, new valves, punchiest set of springs, and a machine shop three angle valve grind to seat them. Ran rough at start-up, had to keep a foot on the gas to keep it running until it warmed up. Then it seemed dandy, except for hard starts after stops to fuel, errands, etc, unless the engine got good and cold again. I chased vacuum leaks at my intake manifold. No joy.

Progress
More than one friend suggested the carburetor could be the issue. As I have "rebuilt" the one I was running on more than one occasion, I bit the bullet and invested in a new carburetor. Initial test drives were very encouraging. Started up and idled without having to keep a foot on the gas straight out of the box. A really minor hiccup of falter from running to accelerating. So onto adjusting the carb, opened up the bypass and thought maybe that was the trick, but noticed the throttle arm wasn't closing entirely. So I pushed it closed and the engine died.

Set-back
Then, the engine wouldn't turn over. This has been an issue because poor Bertha has been sitting this last year, other than a run to Maupin and her debut in the local Amboy Territorial Days Parade. The key has been bypassed, so a switch turns on the ignition, and a button turns over the starter. Dash lights are bright when I turn on the ignition, but starter doesn't spin. I can hear a "whirring" noise, but that's it. Generally I can come back after a bit, try it again, and we get a spin and start. I attributed it to sitting and being a bit "electrical contact corrosion compromised". But this time, no joy. The "whirring" noise I imagine is my starter gear spinning unengaged from the flywheel. Bang on the solenoid. No help. Wondering if I need a new starter. Sheesh, I replaced the one there how long ago? Well, not that recently. Then I get a glow and fade from my dash lights, and nothing. Keee-rist.

Stupidity narrowly averted
I checked all the electrical connections. Solid. I check the voltage of the battery. Barely eleven. Charge the battery and everyone is happy happy happy. Finish adjusting the idle with the bypass screw and go for another little test drive. Seems like it was the ticket ...

But ...
My accelerator cable seems to be sticking, leaving the carb open and a horrifically fast idle until I open the engine hatch and push the throttle arm down. I crawl under and lube up the accelerator cable everywhere I can find to do so. No joy. Maybe it's the new carburetor. Parts quality isn't what they used to be. I disconnect the cable from the carburetor. Carburetor seems fine. I'm not getting a "stuck open" out of it. The plan at that point was to replace the accelerator cable, and with a grease gun fill the tube it runs though with axle grease, and hope that addresses the issue. So today went out and disconnected the cable at the pedal, wondering if I had put the two washers on either side of the cable backwards, as there is a cup action to them, noting an adjustable plate gizmo on the assembly that could be wrong and maybe an issue, although has never been in the past, and generally scratching my head over the engineering of the connection assembly. It seemed odd that my gas pedal would be solely reliant on the spring on the carburetor throttle arm to return to an idle position. Consulted my Bentley, but nothing there, went online and realized there's a spring at the pedal that I have never had.

That must be the ticket. My fingers are crossed.



neal
The slipper has no teeth.

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Amskeptic
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Re: Chasing issues.

Post by Amskeptic » Wed Jun 06, 2018 11:14 am

ruckman101 wrote:
Mon Jun 04, 2018 6:28 pm
realized there's a spring at the pedal that I have never had.

That must be the ticket. My fingers are crossed.

neal
That accelerator spring is only for the accelerator (and serves as a retainer for the pivot pin.

The throttle cable depends solely on the carburetor spring. Too much grease in the cable tube will cause sticking problems at anything under 80*. Just an easy "anti-corrosion" coat on the cable. The metal fan housing accelerator cable tube does need to be well aligned with the tube on the bus itself underneath. They should allow the cable to pass without wall contact at the edges of the respective tubes. Look for any shiny "sawing" spots.
Bertha? Behave.
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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ruckman101
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Re: Chasing issues.

Post by ruckman101 » Wed Jun 06, 2018 9:48 pm

I'm pulling the cable for inspection. The other thought was a tighter spring on the carb. Despite the fact it's as new as the carburetor it came on. But why compound the variables?

neal
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ruckman101
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Re: Chasing issues.

Post by ruckman101 » Thu Jun 07, 2018 9:39 pm

I go in to get the spring missing from my gas pedal assembly, and what the heck, the connecting rod between the pedal and assembly that then pulls the accelerator cable. A kit for $12.50 that has the spring, the mounting plate for the pedal, and the hinge pin. I only need the spring. A helpful mechanic found a box of used such he didn't have faith he could find, and offered a decent connecting rod, and a spring with top retaining hook broken off. A second mechanic listened to my quandary and opined that the spring in question actually was designed to force my accelerator pedal down, not up. He suggested I tighten my carburetor spring. Clip and bend. Curious. Neither had an opinion about the cupped washers I suspected I had installed backwards. I got the opinion that every assembly/connection they had dealt with had been cobbled into a hippie-fix functionality, and good luck.

So it goes.


neal
The slipper has no teeth.

kreemoweet
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Re: Chasing issues.

Post by kreemoweet » Thu Jun 07, 2018 11:45 pm

Early bays never had a "return" spring at the pedal. The normal carb throttle spring is quite sufficient to keep the pedal firmly upright.
A stiffer carb spring will result in faster wear at the throttle shaft bearing points. I remember trying to retrofit a late bay accel pedal spring
to my '71, but was unsuccessful, but can't recall what the issue was. Here's the early bay stock setup:

Image

The diagram doesn't show the N120561 6 mm "clamping plate" that secures the shaft of the V-lever where it goes thru the bracket
welded to the underside of the floor panel.

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ruckman101
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Re: Chasing issues.

Post by ruckman101 » Fri Jun 08, 2018 9:50 pm

Sure isn't what I'm looking at kreemoweet. Not a leaf spring, different accelerator cable end at the pedal. It's a loop. The accelerator pedal lever also looks different. Getting under tomorrow to hopefully resolve issues in order to get back on the road. Could that be for a '71? And the bellows. That's new to me. Is it also a water seal between cabin and street?

I'll get some photos up tomorrow.


neal
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ruckman101
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Re: Chasing issues.

Post by ruckman101 » Sat Jun 09, 2018 6:44 pm

No joy. The cable seems to be binding in the last foot or so of the tube where it bends up and comes out over the transmission and to the fan shroud tube. Should have more power, stumbles when you punch the gas.

sigh, neal
The slipper has no teeth.

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ruckman101
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Re: Chasing issues.

Post by ruckman101 » Sun Jun 10, 2018 6:47 pm

I could try the new cable, but the old one seems alright. Only kinked a tad between where it comes out above the transmission and enters the fan shroud. I guess I'll try that before exploring soaking the tube in degreaser and maybe a reaming of some kind, old clutch cable maybe. Although I did run the old cable in and out of there a few times, twisting it, a little more, twisting it, etc. and did get some goo to follow I wiped away. Shiny spots where the cable bends in the tube, but nothing extreme. Will look again.


neal
The slipper has no teeth.

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Amskeptic
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Re: Chasing issues.

Post by Amskeptic » Tue Jun 12, 2018 4:25 pm

kreemoweet wrote:
Thu Jun 07, 2018 11:45 pm
Early bays never had a "return" spring at the pedal.

Except for the leaf spring #2 in diagram. They all have some means for retaining the pivot pin.
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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ruckman101
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Re: Chasing issues.

Post by ruckman101 » Tue Jun 12, 2018 6:47 pm

I get it. The leaf spring sits into the notch in the middle of the pedal's hinge pin. Hopefully my new one will stay in place without it. The old one did.

So I resolved the issue of the throttle sticking open. I took the carburetor off and noticed that for the accelerator arm to sit completely, it had to force the pump back further than it was going to go. I turned out the plastic retainer nut on the end to loosen it and no more "sticking" open. Now if I only had confidence in my carb adjusting skills.

Power is back, as is a "pop pop pop" while decelerating. And it has a stumble if the pedal is goosed.


neal
The slipper has no teeth.

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ruckman101
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Re: Chasing issues.

Post by ruckman101 » Wed Jun 13, 2018 9:32 pm

I did my best at a textbook "how to adjust your H30-31 carburetor". And like all my other efforts, the engine and response did not correspond to the process. What was supposed to happen didn't. Sigh. It hiccups a bit still to quick demands, and, as before, pops some backfire traversing down steep hills on the engine and gear with no foot on the gas. I'm flummoxed regarding this carburetor adjust thing, in terms of getting it just exactly perfect.

And then twice now, after test runs down and up the hill, I've checked the engine temperature, grabbing the oil dipstick. Can an engine run too cool? Running rich?

Oh the torment.


neal.
The slipper has no teeth.

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ruckman101
Lord God King Bwana
Location: Up next to a volcano.
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Re: Chasing issues.

Post by ruckman101 » Wed Jun 13, 2018 9:39 pm

Maupin bound.
The slipper has no teeth.

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