Bus 1 has issues...

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71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Sat Oct 21, 2017 8:08 am

Latest post of the previous page:

Well it's been raining and winter is coming fast around here. Still distracted with the sno cat needed some attention and snow on the way. I'm now a certified Tucker pontoon puller. It sorta like changing a wheel with a few extra steps to it.
But when the rain lets up I've been driving Bus1 locally and now have about 85 miles on it. Still dry as a bone as far as oil leaks and all I did was change the Pulley back to a stock one. It's actually running pretty good too. Still haven't changed the carb or compression tested but I'm sure the compression is good because there is plenty of power (relatively speaking). Does still have a little idle drop and mostly timing by ear cause the marks are not lining up right, but running well enough to take on a trip I think. I will play around with carb adjustments and timing some more as I drive it. Bus 1 and Bus 2 are starting snuggle up under the carport though and the new car with heated seat sits outside ready to do battle with our PNW winters.

71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Mon May 28, 2018 9:37 am

Well folks I thought I would update this thread. I pretty much winterized Bus 1 and didn’t do anymore wok on it. But now that it’s spring I’ve had it out and trying to put some miles on the new engine. I now have about 400 miles on it. The oil leak is fixed, not a drop and it was due to an after market pulley. I have a stock one on there now and its not leaking any oil at all.
Now the idle drop once it warms up is still a problem. I finally changed carbs out to a known good one that I have used for the last few years. It’s the same. Still idles too low once it warms up. So I put the rebuilt volksbitz carb back on it and seems to run best with this one. So I’ve ruled out the carb.
It’s runs real smooth when I’m on the gas. Idles too slow once it warms up. It really drops down when I put the retard vacuum hose on. I’ve been trying to time it hoses off but when I put the retard hose on it just drops way down. Can’t seem to get the idle or fuel mixture to help it either. I have it advanced just far enough so it will not die at stop signs. Even though I put a timing light on it I’m mostly timing by ear since it’s the only way I’ve been able to get it running well enough to drive it around. Have not done a compression test but can say there is plenty of power and runs real smooth when I give it gas.
This basically frustrates the hell out of me. I’ve been to this point with every long block I’ve put my parts on and then eventually Colin arrives and we get it running perfectly. But this is something I need to be able to figure out on my own. Now Colin is coming in a about three weeks so this is first on my list but I’d sure like to get it tuned myself so we can work on other things.
I can’t find any vacuum leaks. Idle doesn’t change if I’m on the brakes or not. I put a rebuilt brake booster on a few years ago and brakes are all working fine.
I’d love some suggestions and some guidance if anyone has any ideas. Again, Colin will be here in three weeks but I’d like to tackle this before is possible. Thanks for any ideas. :blackeye:

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wcfvw69
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Re: Bus 1 has issues...

Post by wcfvw69 » Mon May 28, 2018 2:24 pm

Tell us which carb and distributor you're running on this bus? Is it a German Solex 34-3? If so, what's the base flange number on the carb? There were two different main versions of those Solex 34-3's. One is the DVDA version (most common) and the other was the SVDA version. You need to make sure the carb matches the distributor. The main difference between the two carbs is the hole in the butterfly/throttle plate. The DVDA version has a bigger hole to allow more air at idle with the timing at 5* BTDC which is where you should be setting a DVDA at idle.
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Mon May 28, 2018 8:10 pm

Ok interesting. This is a 34 pict 3 German carb that I bought at a swap and then sent it to volksbitz for the restore. I’ll go out and check the flange and see if I can see a number.

And the distributor is a 205q with a nos vacuum can #853.

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wcfvw69
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Re: Bus 1 has issues...

Post by wcfvw69 » Mon May 28, 2018 10:45 pm

71whitewesty wrote:
Mon May 28, 2018 8:10 pm
Ok interesting. This is a 34 pict 3 German carb that I bought at a swap and then sent it to volksbitz for the restore. I’ll go out and check the flange and see if I can see a number.

And the distributor is a 205q with a nos vacuum can #853.
If you told Tim you were running a 211905205Q DVDA distributor, he would of set it up for the DVDA if it was an original SVDA Solex carb.
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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SlowLane
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Re: Bus 1 has issues...

Post by SlowLane » Tue May 29, 2018 2:13 am

This may or may not have anything to do with the issue, and my knowledge of the 34PICT-3 pretty much extends to just this one tid-bit from when I had my '72 Super Beetle. I grok F.I. much better than I've ever understood carbs.

I recall that the carb had a small port or jet or something facing down on its base just on the periphery of the inner bore, and the manifold had a corresponding notch in it which served to expose the port or jet to the intake manifold vacuum. I further recall that the base gasket that came in the carb rebuild kits of the time often didn't have a notch cut into it for this port/jet, and so effectively blocked it off, causing some weird behavior. But I couldn't tell you what weird behavior. Maybe someone else has a better idea on this.

Edit: Memory is starting to thaw now. I think the port I speak of was the vacuum take-off for the retard side of the distributor can. Have you tried putting a vacuum gauge on the retard line and confirming that you have full manifold vacuum there at idle?
'81 Canadian Westfalia (2.0L, manual), now Californiated

"Wisdom comes from experience. Experience is often a result of lack of wisdom."
- Terry Pratchett

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asiab3
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Re: Bus 1 has issues...

Post by asiab3 » Tue May 29, 2018 6:56 am

How many turns out is your big brass idle speed screw? Write it down for experimenting.

Once the engine is fully warmed up, give it four or five more turns out, really! This is to give the idle bypass circuit a fighting chance against the “inefficiency” that is retarded idle timing. You may need a few turns out of the small idle mixture screw, too. Experiment with large changes to learn how they affect your engine! (Once you’ve written down your baseline so you can always resort back!)

Sunnydog’s big idle speed screw needed to come out so far the face of the screw was almost flush with the carb body. Bentley is very prim and proper with the “two and a half turn” method but I really do believe that we should be asking the engines what they want, even if it means more screw turns and some experimenting.

Of course, before going down this path, the idle cutoff solenoid must be intact and functioning, and vacuum leaks must be ruled out.

Good luck!
Robbie
1969 bus, "Buddy."
100k miles with me.
279k miles on Earth.

71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Tue May 29, 2018 8:02 am

Thanks guys. I did tell Tim that it was for a stock 1600dp with the dvda 205q.
I’ll play around more with the idle and fuel mixture. I can’t seem to find any vacuum leaks but I suppose it’s possible. I have checked several times in all the places I know about. Sprayed carb cleaner all over.
I’ll report back after I dig into it a bit more.

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SlowLane
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Re: Bus 1 has issues...

Post by SlowLane » Tue May 29, 2018 6:00 pm

Have you tried timing it per Colin's favorite method? Hoses off, 28 BTDC @ 3200 RPM (or numbers kinda in that realm, I can't recall exactly.)?

Then you just let the idle timing fall where it may and Stop Worrying. :flower:

Unless you're required to have factory idle timing for smog testing like here in CA... :geek:
'81 Canadian Westfalia (2.0L, manual), now Californiated

"Wisdom comes from experience. Experience is often a result of lack of wisdom."
- Terry Pratchett

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asiab3
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Re: Bus 1 has issues...

Post by asiab3 » Wed May 30, 2018 6:18 am

When you time the 205q like that, it drives wonderfully but the idle timing absolutely will fall quite retarded, as designed. The carb will require massive airflow through the idle circuit to compensate for the designed-in inneficciency. They drive beautifully once the idle circuit is tuned correctly.

Robbie
1969 bus, "Buddy."
100k miles with me.
279k miles on Earth.

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Amskeptic
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Re: Bus 1 has issues...

Post by Amskeptic » Wed May 30, 2018 7:16 am

Just a quicky test, Sean.
A) remove retard and advance hoses, block off if you are in a sandstorm
B) establish Timing Which Shall Not Be Screwed With Henceforth (28-30* @ 3,400 rpm)
C) with your warm engine running however it runs, turn out big brass screw as much as you can whilst still being screwed in somewhat (i.e. Robbie's mention of even all the way flush with the outer lip of the bore)
D) what is the idle speed?
E) pull off the cut-off solenoid wire - what happens?
If no change, your problem is here. If it dies, reattach wire, restart, and:
F) no matter the consequence, reattach the retard - what is idle speed now?

This is simple stuff, and we need to stay within the sturdy guardrails of focused diagnosis. An engine that runs well otherwise, is an engine that runs well otherwise. The most complicated problem here is as SlowLane suggested, the bypass air passage may be blocked at the base gasket or you have a plugged fuel passage that feeds the bypass circuit . . . but first! the cut-off plunger must successfully retract! It can click and not be actually pulling the plunger back. Oddly, I have found that people put o-rings here thinking it will seal things, and that can not only interrupt the electrical ground but also remove the necessary "preload" on the plunger. If you ever test the cut-off off the engine, you need to ground the body of the plunger AND apply a light finger pressure to the plunger to see if it correctly snaps back.
It is all fun, so is 102* in Phoenix, it really is.
Colin
BobD - 1978 Bus . . . . . . . . . . .111,130 miles
Chloe - 1970 bus . . . . . . . . . . . 206,787 miles
Naranja - 1977 Westfalia . . . . . 94,615 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 72,990 miles

71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Wed May 30, 2018 8:16 am

Ok thank you all for the suggestions. I’m heading out there to warm it up and see if I can retime it and readjust it. I know the cut off solenoid works because I’ve switched it out with a known working one and it made no difference, just did this the other day.

71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Wed May 30, 2018 9:09 am

Well maybe, just maybe we are on to something here, lol! I know this is simple stuff too and that’s why it drives me a little nuts.
I retimed it to 28-30 degrees and I did have it a bit adavanced to keep it running. So reset it correctly and then screwed the idle adjust way out and then screwed the fuel mixture out about three more turns. I am thinking the problem more or less is in the fuel mixture. I then had to screw in the idle adjust to bring the idle back down. I have yet to take it for a drive but so far I think this is the right direction. I have high hopes for my test drive later today. I’ll report back later. Thank you all for the help, it’s appreciated more than you know.

71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Wed May 30, 2018 7:34 pm

And maybe we’re not on to something....
Been driving around today and it still wants to die at idle. Now it seems to not want to idle on start up either, like the choke isn’t working. Don’t think that’s the issue though. I retarded the timing a bit because I had it too far advanced and I unscrewed the idle adjustment way out and also the fuel mixture. Went way out with both and playing around with them somewhere in between too. I have not counted how many turns out but a lot. Something is still fishy and driving me nuts. Thought I had it earlier cause it was idling a little on the fast side and now is has settled way low. I feel dizzy with all the unscrewing, retarding and advancing. I’m just at a loss here and can’t believe I can’t figure it out.

71whitewesty
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Re: Bus 1 has issues...

Post by 71whitewesty » Wed May 30, 2018 7:57 pm

And now just drive it home about 6 Miles and it’s idling a little high again. Took a few cranks to start up too. Didn’t want to idle at first and then (this time) started to idle once it warmed up a bit. Why....please tell me why... seems ridiculous I can’t figure this simple stuff out.

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SlowLane
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Re: Bus 1 has issues...

Post by SlowLane » Wed May 30, 2018 9:12 pm

With all this to-ing and fro-ing, have you refreshed your distributor's centrifugal advance mechanism so that it tracks the RPM changes smoothly? Or is it still lumbered with 46 year old grease? You said that you have a few 205q dizzies, but are they all smooth operators?
I was astounded at how much better my van ran after I disassembled the distributor, cleaned it up and lubed it. Night and day difference.

Yeah, sorry, careering right through the guardrails of focussed diagnosis here. :joker:
'81 Canadian Westfalia (2.0L, manual), now Californiated

"Wisdom comes from experience. Experience is often a result of lack of wisdom."
- Terry Pratchett

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