Author Topic: baywindow aircare fail  (Read 10281 times)

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Offline synner88tc

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baywindow aircare fail
« on: January 03, 2011, 07:47:31 PM »
So my 76 baywindow (2.0L FI. all stock but the EGR valve is not hooked into the exhaust. it is there and the power and vac lines are hooked up just no filter and no exhaust) has been sitting for a number of years. Recently I drained the fuel tank and replaced all the fuel lines and filters. I set the valves, points, timing (7.5btdc), half a bottle of methyl hydrate. then decided to run it through aircare for a baseline or hopeful pass.

Failed in idle HC

Reg#08704771

Next I replaced the cap, points, condenser, plugs, wires, checked all vacuum lines, re-checked the timing both statically and with a light. premium gas (huskey) and a little more methyl hydrate for good measure. I also raised the RPM to about 1000rpm

I ran it through tonight and failed again but this time it was driving CO that got me. The idle test was good.

I pulled out into the parking lot and retarded the timing a bit to about 0 degree's and brought the idle back up to 1000rpm again and re-tested. it got better but still no love.

I double checked my point's gap when I got home on a dwell meter and they are a little out I was reading about 46-47 degree's on it, but I have never used this meter before and don't know how accurate it is. I set them with a feeler gauge to .016"

What should I be looking at here? should I try to retard the timing more? I see that when I adjusted it the second time that driving HC and CO went down but everything else went up. I have not touched the idle mixture screw.

Should I be concerned about the EGR valve? all my driving numbers were good in the first run, and I don't think it is in play when at idle.


Thanks in advance! Any help would be greatly appreciated!
« Last Edit: January 04, 2011, 04:21:44 PM by synner88tc »

Offline Jerome

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Re: baywinder aircare fail
« Reply #1 on: January 03, 2011, 09:04:19 PM »

Should I be concerned about the EGR valve?

Since it seems you have tried every other trick
I would suggest replacing it.....   or put carbs on ;D
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Offline Hansk

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Re: baywinder aircare fail
« Reply #2 on: January 03, 2011, 09:46:16 PM »
First , never ever never put methyl hydrate in your gas tank. Its extremely corrosive to your tank, lines ,fuel pump , injectors etc.   The EGR was there to reduce nox , you'll probably get by with out it. If all else is good (fuel pressure , head temp sensor , injectors , oil change ,compression ,etc etc etc ) you could try adjusting the air bypass on the flow meter. (the one under the plug that prevents you from adjusting it)  I'm thinking you may want to turn out to allow more air to bypass the flow meter. Ideally this should be done at a shop with a gas analyzer but....I've done this in the parking lot to get myself through.
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Offline pittwagen

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Re: baywinder aircare fail
« Reply #3 on: January 03, 2011, 10:08:24 PM »
Just a couple of comments from someone who has recently been through Aircare with a van than had never been tested before, at least in Canada and not for a long time.

How long has the van sat.  If it was for a long time, you need to have driven it for a few hundred miles to get everything working properly - rings seated etc.  The engine needs to be good and hot before testing.

Go to someone who is familiar with this engine and can hook it up to a gas analyser and get it set right.  Your CO at both idle and driving is too high.  That may be a simple mixture adjustment or it may be more complicated.

Maybe it is just the mixture at this point so do this first - with the analyser.

It looks like your van has a history of failures according to the records.  Has it sat for extended periods.  If so, there may be other issues that need to be looked at.  How's the fuel pressure and injectors?  A lot of folks in that situation will automatically replace the temp sensor, fuel pressure regulator and have the injectors serviced.  I always test the fuel pressure and check the injector spray patterns on any FI vw that I buy.  Oh and don't forget the cold start valve.  Then I know about all the fuel components.

You've don the fuel and vacuum lines and the fuel filter. Good.  Nice steady idle?

It cost me $90 at the garage for the analyser time and it was time and money well spent.  My numbers are considerably lower than yours right across the board.  I have no EGR, no cat and I run regular gas and nothing else.

Good luck.

Offline BUSDADDY

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Re: baywinder aircare fail
« Reply #4 on: January 04, 2011, 10:18:32 AM »
First thing to do is drain the gas and put in some good old regular, methyl hydrate and ethanol may be OK for modern cars but it's not what your bus is designed to burn and premium of any kind is a waste of your money.
Then invest in a timing light,disconnect the hoses to the distributor and set your timing to 28 degrees at around 3000-3500 RPM (wherever the mark stops advancing as you rev the engine), put the hoses back on.
Now remove the vacuum advance line from the plenum and try sucking on it, it should hold a vacuum (a Mightyvac tool is best for this but your mouth will do for a test), if it doesn't hold a vacuum the EEC valve on the aircleaner or the advance pot on the distributor is NFG. Put a golf tee in the line to the EEC valve if it fails your test for now, if the distributor fails you need a new vacuum can.
Test your temp sensor 2 as outlined in your Bentley manual, or install your spare just for kicks (you do carry a spare one, right?).
A fuel pressure test wouldn't hurt either and confirm that you have no vacuum leaks or rotted hoses, L-jet can't stand leaks.

There is no magic trick or snakeoil additive for passing Aircare but it's easy if your bus is tuned properly, sounds like yours is struggling.

BTW disconnect and cap that EGR, as you describe it now you're sucking dirty unfiltered air from beneath the bus anytime you're close to full throttle, not good. It'll also cause a lean mixture and aid in the demise of your heads.

Good luck.
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Offline synner88tc

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Re: baywindow aircare fail
« Reply #5 on: January 04, 2011, 04:52:01 PM »
Thanks for the replies!

I am going to do as Busdaddy suggests and then I will make an appointment to see Duane to fine tune the mixture before I try to run it through again.

Just to confirm that I understand correctly regarding the timing. I should hook up the timing light and rev the engine up towards 3000-3500 as I watch the paint mark advance along the scale, at the point that it stops advancing (and the rpm is at or around 3000-3500) I adjust the timing so the mark is at 28 BTDC? then release the throttle.

I have a stupid question about the timing light I am using. It has a dial on the back with a scale from 0 degree's up. when setting the timing the way I am going to be do I leave the dial at 0 degree's or set it to 28? I am kind of thinking that if i set it to 28 then I would line up my paint mark at 0 on timing scale and if the dial is set to 0 I line my paint mark up with 28 deg on the scale does that sound right?

I will also disconnect the EGR.

Thanks again everyone!

Offline BUSDADDY

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Re: baywindow aircare fail
« Reply #6 on: January 04, 2011, 07:53:13 PM »
Excellent!, Duane will get it under control.
The type 4 has a nice timing scale so you can leave the advance feature on the light set to zero, if you didn't have the scale and just had a TDC mark the advance feature on the light is priceless. You are correct about revving until it stops advancing, I leave the distributor clamp a bit loose and watch as I rev, if it comes up short I move the disributor a bit and try again until I find the happy spot, then tighten the clamp and rev one more time to check. After 34 years your distributor may not perform exactly like it did in 76, setting it at maximum mechanical advance (hoses off) and letting the idle fall where it likes ensures the timing is correct where you use it, unless you drive around at idle speed all day ;) After you get it timed reconnect the hoses and try again with the light, it should get close to 40 degrees BTDC momentarily as you open the throttle rapidly, if it doesn't suspect the vacuum can on the distributor.
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Offline Bruce

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Re: baywindow aircare fail
« Reply #7 on: January 05, 2011, 12:35:30 AM »
If you look at your test report, it says your Bus is 2000kg.  I have a hard time believing it weighs 4400lbs.  There must be some other Bus guys on here that can tell you what their weights are on their aircare reports. It should be on your ICBC papers.
Getting this corrected is very important.  It is because the cutoff numbers that determine if you pass or fail are based partly on the weight of the vehicle.  Heavier = lower cutoffs = hard to pass.  It's my guess you are overweight by at least 1000 lbs.  This will make a HUGE difference in the cutoffs.
Another change you need to make is the engine size.  Everyone knows it's a 2 liter engine, but in fact it's really 1971ccs.  Aircare allows you to truncate the engine size.  A smaller engine gets you higher cutoffs.  It's not much, but if you look at your reports, you have one failing reading of 2.51% CO.  I believe the cutoff for that is 2.50%.  Had you the smaller engine in their system, you would have passed.  Changing this is easy.  Just tell the guy at the test station that its really a 1.9 liter engine.  They can change it right there.

What distributor do you have?  Is it a single vacuum hose or two?

Offline Bruce

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Re: baywindow aircare fail
« Reply #8 on: January 05, 2011, 12:39:08 AM »
and letting the idle fall where it likes ensures the timing is correct where you use it, unless you drive around at idle speed all day ;)
The problem is, you can't ignore the idle timing when it comes to aircare, because they do a whole test at idle only.  If the timing is too far advanced, you're doomed to fail the HC reading.

Offline BUSDADDY

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Re: baywindow aircare fail
« Reply #9 on: January 05, 2011, 06:24:50 AM »
and letting the idle fall where it likes ensures the timing is correct where you use it, unless you drive around at idle speed all day ;)
The problem is, you can't ignore the idle timing when it comes to aircare, because they do a whole test at idle only.  If the timing is too far advanced, you're doomed to fail the HC reading.
Good point Bruce, so check it with the light and if it's horribly wrong reset temporarily for the test and put it back after, you'll need the numbers off the side of the distributor to determine the idle setting. Of course if it's horribly wrong you have serious distributor issues as well.

Empty weight is 1495 KG BTW.
« Last Edit: January 05, 2011, 07:09:08 AM by BUSDADDY »
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Offline pittwagen

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Re: baywindow aircare fail
« Reply #10 on: January 05, 2011, 09:02:35 AM »
Oh my, we've got the heavyweights involved.  Bruce, you should be down south.  BUSDADDY, the Samba will be missing you. 

Is this vehicle a Campmobile?  If so, 1495kg. is correct for the curb weight.  If not, it could go as low as 1245kg. if it is a delivery van (according to my 79 owner's manual) and the lower curb weight number will affect the driving Aircare #'s. 

You could always go by your local weigh scales and get it checked.  We have one here in Pitt Meadows at the garden supply place by the bridge.  No charge.  I used them to get a weight for my dune buggy when I registered it a couple of years ago.  ICBC took the slip, no questions.  Just remember to get out of the vehicle when they weight it!!

My 79 Deluxe is registered with a 1302kg. curb weight.  Don't know where ICBC got that but it does result in a slightly higher threshold for HC,CO and NOX when compared to the 1380kg. VW says it weighs. 

My van spent most of its life in the San Jose, California area so perhaps something was incorrectly entered when it was registered in BC, 5 years ago.  I'll take the lower # but hopefully I won't need it.

Bottom line - the Aircare #'s are generous.  If you vehicle is set up and running properly, you shouldn't come close to their max. readings.

Offline Bruce

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Re: baywindow aircare fail
« Reply #11 on: January 05, 2011, 10:31:03 AM »
and letting the idle fall where it likes ensures the timing is correct where you use it, unless you drive around at idle speed all day ;)
The problem is, you can't ignore the idle timing when it comes to aircare, because they do a whole test at idle only.  If the timing is too far advanced, you're doomed to fail the HC reading.
Good point Bruce, so check it with the light and if it's horribly wrong reset temporarily for the test and put it back after, you'll need the numbers off the side of the distributor to determine the idle setting. Of course if it's horribly wrong you have serious distributor issues as well.
I think the real solution is to rebuild the distributor so it works the way it should.  If it's not right and you have to fudge the settings for aircare, the Bus isn't gonna run right ever, no matter how you set it later.

Offline pittwagen

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Re: baywindow aircare fail
« Reply #12 on: January 05, 2011, 11:14:30 AM »
Just so that the original poster is not confused, a distributor problem has not been identified yet, correct? 

He was advised how to set the timing which may, or may not result in too much advance at idle and this could affect HC.  That can be identified with the gas analyser hooked up.

I had that issue with mine (setting total advance to 28 deg.).  The numbers were somewhat high.  With the analyser hooked up, I simply retarded the timing slightly and the readings fell into an acceptable level.  Slight tweaking with mixture and idle speed and all was well. 

Offline BUSDADDY

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Re: baywindow aircare fail
« Reply #13 on: January 05, 2011, 12:32:47 PM »
Yes, his distributor may be just fine, your's on the other hand sounds like it's sticking internally.
If his is a DVDA (some 76's had them IIRC) then it should idle at an ATDC number after he reconnects the hoses.
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Offline pittwagen

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Re: baywindow aircare fail
« Reply #14 on: January 05, 2011, 12:51:22 PM »
Don't think so.  Had the distributor out of the bus, checked the vacuum can, advance mechanism etc.  Hey it's 31 years old with somewhere 150,000+ miles so it's not perfect.  Love to find something less well travelled along with the other bits of unobtanium that are on a 79 California emissions bus. 

In the meantime, it passed Aircare and gets decent gas mileage. 

Should have installed that BN4 though.  Not as tough as I was when I owned my last Bay.

Offline synner88tc

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Re: baywindow aircare fail
« Reply #15 on: January 06, 2011, 12:36:45 PM »
ok so after setting the timing at max advance and releasing the throttle do I adjust the idle back to 900ish rpm or am I doing that first and leaving the idle where it lands after the timing.

Distributor is vacuum can with 2 hoses. I can get the numbers later today if need be.

I will look into changing the weight and CU IN on the registration.

The bus is a standard passenger Bay.  no camper, no pop top.


Thanks again for all the help!

Offline BUSDADDY

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Re: baywindow aircare fail
« Reply #16 on: January 06, 2011, 01:58:00 PM »
Set the timing, then reconnect all the hoses, then adjust the idle, when you're all done see what the idle timing is just for the hell of it.
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Offline Bruce

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Re: baywindow aircare fail
« Reply #17 on: January 06, 2011, 02:21:29 PM »
Distributor is vacuum can with 2 hoses.
This is the whole cause of your trouble.
The dual vacuum distributor needs to be timed to 5ºATDC at idle, with both hoses connected.  Previously, you stated you had it at 7ºBTDC.  This will put your timing WAAAAAY too advanced.
Set the timing to 5ºATDC at 900-1000rpm.  Then while holding the timing light on the marks, slowly crack open the throttle.  Just as you open the throttle, the timing should quickly jump to about 7ºBTDC, then climb from there as the revs rise.
If the timing does not jump as I described, either your vacuum pot is no good, or you have the hoses connected to the wrong place.  I've seen professional VW mechanics get this wrong.

While you're at it, check the dwell.  Spec is 47 +/- 3º.  Above, you stated you set it to .016".  While that is a good start point, the dwell angle is the precise value you are shooting for.  
Changing the dwell changes your timing.
« Last Edit: January 06, 2011, 02:25:14 PM by Bruce »

Offline synner88tc

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Re: baywindow aircare fail
« Reply #18 on: January 07, 2011, 01:02:16 PM »
The bentley has 1976 FI buses at 7.5 BTDC and 75 FI buses at 5 ATDC.  The Bentley states that buses with VIN number 2262077583 and back are at 5 deg ATDC and VIN numbers 2262077584 and after should be 7.5 deg BTDC

The stickers on my engine lid and the engine itself also say 7.5 BTDC

BUT I have the EARLIER VIN!?!


I set the points gap at .016" and then checked it on a dwell meter and it came up at roughly 46 degree's. Bentley says 44 - 50 (and so do you)

Offline BUSDADDY

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Re: baywindow aircare fail
« Reply #19 on: January 07, 2011, 01:16:38 PM »
If the distributor has 2 hoses it's the ATDC setting, the 7.5 is for a single hose unit. You may not have the original distributor, what is the number on the side of it? There also may not be the correct ports on the throttle body or plenum to properly operate that unit, 75-76 had some odd mid year plumbing and system changes.

Time it to 28 degrees BTDC at speed/hoses off and only reconnect the advance line after (smaller one that points away from the distributor), plug the retard line (often green) coming from the engine and leave the retard port open on the distributor, the timing at idle should fall near 7.5 BTDC like that.
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Offline synner88tc

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Re: baywindow aircare fail
« Reply #20 on: January 07, 2011, 01:28:10 PM »
well that makes sense, because when I retarded the timing a little in between the last 2 tests the numbers got better and it turns out I am way advanced right now.

Ok I will get this done sometime in the next few days and see what it does.

Thanks!

Offline Bruce

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Re: baywindow aircare fail
« Reply #21 on: January 07, 2011, 03:32:08 PM »
Time it to 28 degrees BTDC at speed/hoses off and only reconnect the advance line after (smaller one that points away from the distributor), plug the retard line (often green) coming from the engine and leave the retard port open on the distributor, the timing at idle should fall near 7.5 BTDC like that.
I disagree with this.
Time it to VW's spec. 
With the idle timing at 5ºATDC, the HC numbers will be a LOT lower than if the idle retard function was disabled like you suggested.  There is no performance advantage to disabling the retard part of the distributor.  Driveability is unaffected because the only time the distributor is in the retarded state is when your foot is off the throttle.

Offline Bruce

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Re: baywindow aircare fail
« Reply #22 on: January 07, 2011, 03:42:48 PM »
The bentley has 1976 FI buses at 7.5 BTDC and 75 FI buses at 5 ATDC.  The Bentley states that buses with VIN number 2262077583 and back are at 5 deg ATDC and VIN numbers 2262077584 and after should be 7.5 deg BTDC

The stickers on my engine lid and the engine itself also say 7.5 BTDC

BUT I have the EARLIER VIN!?!
Forget about the stickers and the VIN.  When you have the dual vacuum dist, you time it to 5ºATDC.  All you need to do is make sure your throttle body has the correct vacuum ports to make it work.  If it does, this distributor is the Aircare KING!  It gives you massive retard at idle so you have the lowest possible HC, but when driving, it works exactly the same as the single vacuum distributor.  It's a win-win.  There is no reason whatsoever to disable it.

Offline BUSDADDY

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Re: baywindow aircare fail
« Reply #23 on: January 07, 2011, 05:34:54 PM »
Time it to 28 degrees BTDC at speed/hoses off and only reconnect the advance line after (smaller one that points away from the distributor), plug the retard line (often green) coming from the engine and leave the retard port open on the distributor, the timing at idle should fall near 7.5 BTDC like that.
I disagree with this.
Time it to VW's spec. 
With the idle timing at 5ºATDC, the HC numbers will be a LOT lower than if the idle retard function was disabled like you suggested.  There is no performance advantage to disabling the retard part of the distributor.  Driveability is unaffected because the only time the distributor is in the retarded state is when your foot is off the throttle.
Normally I wouldn't recommend such a thing but Synner may have some odd parts in the mix here, if you are positive the distributor is indeed the correct one for that particular vacuum plumbing setup, and you are absolutely sure it's plumbed correctly, and you are sure the distributor is advancing/retarding correctly then time by the book. But if the answer is no to any of these questions you may be better off disabling the retard, I'm aware it's not a performance enhancement on a properly functioning system to disable it but if it's connected to a supply of constant vacuum you'll be in constant retard mode, likewise if the diaphram is leaking it'll skew all the idle settings.
Time it with the light, connect all the hoses and see if the timing jumps forward and stays there when you crack the throttle, if it jumps a little and goes back or doesn't change at all consider plan B.
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Offline Bruce

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Re: baywindow aircare fail
« Reply #24 on: January 07, 2011, 10:37:28 PM »
Time it to 28 degrees BTDC at speed/hoses off and only reconnect the advance line after (smaller one that points away from the distributor), plug the retard line (often green) coming from the engine and leave the retard port open on the distributor, the timing at idle should fall near 7.5 BTDC like that.
I disagree with this.
Time it to VW's spec.  
With the idle timing at 5ºATDC, the HC numbers will be a LOT lower than if the idle retard function was disabled like you suggested.  There is no performance advantage to disabling the retard part of the distributor.  Driveability is unaffected because the only time the distributor is in the retarded state is when your foot is off the throttle.
Normally I wouldn't recommend such a thing but Synner may have some odd parts in the mix here, if you are positive the distributor is indeed the correct one for that particular vacuum plumbing setup, and you are absolutely sure it's plumbed correctly, and you are sure the distributor is advancing/retarding correctly then time by the book. But if the answer is no to any of these questions you may be better off disabling the retard, .....
While that is true, assuming his setup is fucked with no evidence, then disabling the feature that will make him pass "just in case" isn't gonna help one bit.

Synner, are the two hoses hooked up to the throttle body?  Can you post a pic showing where they are connected?
« Last Edit: January 07, 2011, 10:48:52 PM by Bruce »

Offline BUSDADDY

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Re: baywindow aircare fail
« Reply #25 on: January 08, 2011, 09:46:23 AM »
Time it to 28 degrees BTDC at speed/hoses off and only reconnect the advance line after (smaller one that points away from the distributor), plug the retard line (often green) coming from the engine and leave the retard port open on the distributor, the timing at idle should fall near 7.5 BTDC like that.
I disagree with this.
Time it to VW's spec.  
With the idle timing at 5ºATDC, the HC numbers will be a LOT lower than if the idle retard function was disabled like you suggested.  There is no performance advantage to disabling the retard part of the distributor.  Driveability is unaffected because the only time the distributor is in the retarded state is when your foot is off the throttle.
Normally I wouldn't recommend such a thing but Synner may have some odd parts in the mix here, if you are positive the distributor is indeed the correct one for that particular vacuum plumbing setup, and you are absolutely sure it's plumbed correctly, and you are sure the distributor is advancing/retarding correctly then time by the book. But if the answer is no to any of these questions you may be better off disabling the retard, .....
While that is true, assuming his setup is fucked with no evidence, then disabling the feature that will make him pass "just in case" isn't gonna help one bit.

Synner, are the two hoses hooked up to the throttle body?  Can you post a pic showing where they are connected?
I didn't say leave it like that anywhere, I first suggested it as a test of the distributors function (plug the hose because it won't idle at all with the retard hose open, big vacuum leak), but if when he connects it all up and suddenly gets no advance then I suggested he consider deleting it. I'm also not assuming anything is wrong yet but the discrepancy between the VIN and how it's equipped hint of a little PO debauchery somewhere, I still would like to know what number the distributor is and where the hoses go.
Late 76's with the SVDA pass aircare just fine @ 7.5 BTDC BTW.
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Offline Bruce

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Re: baywindow aircare fail
« Reply #26 on: January 08, 2011, 10:07:03 AM »
If there's a problem with anything to do with the dual vacuum distributor, he's better off FIXING it, rather than DELETING it.
While your engine may pass with a single vacuum distributor, his doesn't pass with it's current setup.  He needs everything going for him to pass.

Offline synner88tc

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Re: baywindow aircare fail
« Reply #27 on: January 08, 2011, 10:06:40 PM »
http://www.ratwell.com/technical/VacuumHoses.html

According to this article the set-up I have (DVDA) is normal for my early VIN. I also have a 79 panel and it also has the DVDA which also agree's with the article.

If you scroll down to almost the bottom of the page there are 2 diagrams of vacuum hose layouts. Mine is plumbed the way shown in the left diagram.

Offline Bruce

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Re: baywindow aircare fail
« Reply #28 on: January 09, 2011, 12:37:40 AM »

Time it to 5ºATDC at idle. 
Then while holding the timing light on it, unplug the retard hose (the green one nearest the dist body) and watch the timing advance to about 7ºBTDC. 
If it doesn't do this, you have to find out why.  There could be a couple of causes.  If your throttle plate isn't closed enough, the retard function won't happen.  The retard diaphragm could be bad too.

Offline synner88tc

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Re: baywindow aircare fail
« Reply #29 on: January 10, 2011, 04:01:00 PM »
ok here is the update:

I removed the vacuum line going to the EGR

I set the timing to 5 deg ATDC at idle (approx 950RPM)

I watched with the timing light and removed the retard hose and timing dropped back to approx 7.5 BTDC. I replaced the retard hose.

dwell reads 46-47 both at idle and at 2000 rpm

while watching with the timing light I slowly brought up the rpm's I hit 28 deg BTDC at approx 2100rpm it continued to advance to near the end of the scale at around 3000. My scale is only readable to 28 so I don't know exactly where it is stopping.

I took it for a drive around my parking lot and it seemed to do well, I am doing day permits to do the tests so I can't take it any further until the next permit and I think I will do it on a day when I am able to go out first thing in the morning and Duane is in the shop.