Newly Rebuilt Engine Questions 1980 Vanagon

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Amskeptic
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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by Amskeptic » Sun Oct 12, 2014 8:15 am

cegammel wrote:I hate to ask...but how would a leak between the head and cylinder behave? I have this annoying oil drop clinging to my lower baffle...and it frightens me...
If the head were loose to the head, you would hear a very brief canary chirp during the first start of the day.
With your prior discussion of leaky pushrod tubes, I would suspect them first.
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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SlowLane
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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by SlowLane » Mon Oct 13, 2014 11:25 am

cegammel wrote:How does the thermo-time switch work? Would it cause bucking and engine constipation?
Getting back to this earlier question.
The thermo-time-switch controls the operation of your cold-start valve. If it's unplugged, then the cold-start valve will not open and deliver fuel during a cold start (or at any other time, for that matter). There shouldn't be any other impact to drivability.

I've never heard a report of a failed thermo-time-switch, they seem to be pretty robust. But if one were to fail, I suspect the most likely symptom would be a cold-start-valve that stayed open all the time. The pig-rich condition resulting from this would probably be pretty noticeable.
'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."
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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Mon Oct 13, 2014 5:48 pm

Thanks. I must have knocked it loose while checking vacuum hoses...I have convinced myself that my issue is a faulty coil and worn plug wires. Those are items that I have not yet replaced, and are not within Bentley specs... When they come in, and don't work, I will jump back on injectors and go from there.

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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by Amskeptic » Tue Oct 14, 2014 8:29 am

cegammel wrote:Thanks. I must have knocked it loose while checking vacuum hoses...I have convinced myself that my issue is a faulty coil and worn plug wires. Those are items that I have not yet replaced, and are not within Bentley specs... When they come in, and don't work, I willget Colin out here since he is in Georgia through the 18th
:flower:
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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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Tue Oct 14, 2014 2:41 pm

Got a spare half Saturday coming up? I may be able to work something out...

So, as for this .5 volt from the OXS mixture test. Mine starts low (.4) and moves to .5 as it reaches 250* CHT. I want to do some more trials at varying engine speeds, but that sounds like pretty good mixture to me. The AFM wiper wiggle with a warm engine puts me right in the middle of the range (1/4" each way causes the engine to stumble).

New plug wires are on; I'm still waiting on that coil.

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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Tue Oct 14, 2014 2:44 pm

I have the wife's official permission to request a half day...

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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Tue Oct 14, 2014 4:34 pm

I also feel a cold coming on; it could arrive Friday morning until 11:35...

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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by Amskeptic » Wed Oct 15, 2014 5:24 am

cegammel wrote:I also feel a cold coming on; it could arrive Friday morning until 11:35...
:drunken:
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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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Wed Oct 15, 2014 5:07 pm

Well...this is embarrassing. I replaced the plug wires (two of the old ones were out of Bentley specs)...marked improvement, but still same coughing issues as before. I replaced the coil, also out of spec, with again, marked improvement...but still didn't fix the issue. Then, I pulled the fuel pump relay, and cleaned each side, then reinstalled. Then, each fuel injector plug, cleaned, pulled down the boot, checked the connections, and reinstalled. That apparently did part of the trick. No more stumble, no more surging...but...new problems. So, I had previously adjusted the mixture screw a bit, and fixing the none firing fuel injector required a readjustment. That done, the engine sounds pretty good. Timing is on, idle is on, mixture looks good (I'm not so good at this one).

But, I still have a hesitation when I open the throttle, and the van just feels very weak. I really wonder now about a slipping clutch. If the rear seal on the transmission was shot (I have a drip from the rear of the transmission), would it leak enough juice to wet the clutch? would that cause the wheels to not keep up with the engine?

This transmission is used, but newly installed (in May). It works well, but now this drip... If it helps, the donor van had 114K miles on it, supposedly original transmission; I've put about 900 on it.

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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by Amskeptic » Thu Oct 16, 2014 11:23 am

cegammel wrote:Well...this is embarrassing, the engine sounds pretty good.

I still have a hesitation when I open the throttle, and the van just feels very weak. I really wonder now about a slipping clutch.
PM for you.

Engine idling. Put in 3rd gear Let out the clutch as though you are taking off in 1st.
Stalls? Clutch OK.
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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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Thu Oct 16, 2014 1:16 pm

Ok, not the clutch. Back to the board.

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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by Amskeptic » Thu Oct 16, 2014 6:05 pm

cegammel wrote:Ok, not the clutch. Back to the board.
We SHALL answer these vexing questions in ten days (cough, cough) . . .
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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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Fri Oct 17, 2014 3:29 pm

I really hate it when Colin is right...

I did the ECU plug test (24.15), and found nothing out of spec. I cleaned electrical plugs again. I fired it up. It did all the same silliness. I wiggled the T2S...problem fixed. I found a break just where the T2S wire leaves the harness bundle. Cut/Splice/Replace plug. Problem solved? NOPE. As it turns out, when I was wiggling the T2S, I was also bumping the loose (probably from all my cleaning and messing around earlier...) the #3 FI plug.

And that's when the revelation hit. When all of these issues began, my VDO CHT gauge dropped from its normal running temp of just below 300* to 125*. I thought that reading was a little strange, but this was my first highway run in 50* weather, so I thought that maybe... As it turns out, when there ain't no gas in the head, it stays a little cooler...

So it seems:

My ignition components were weak. Replacing wires and the coil made a big difference in power.
My T2S had a bad wire (even though the ECU plug check showed good; the break was intermittent).
My #3 FI plug was loose.

Has anyone bought a KYLE wire harness( http://www.kyleautomotivespecialties.com/) ? Any ideas on cost of a new harness with new plugs? It seems that mine is very fragile.

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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by luftvagon » Fri Oct 17, 2014 8:03 pm

You can build your own too..
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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Re: Newly Rebuilt Engine Questions 1980 Vanagon

Post by cegammel » Sat Oct 18, 2014 4:18 am

At 10 bucks per plug, I wonder how soon my unskilled endeavors there would prove economically disadvantageous... I will look into it.

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