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summer samba
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Joined: July 03, 2011
Posts: 57
Location: East coast
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 Posted: Thu May 10, 2012 2:09 pm Post subject: After timing adj. lack of power, stall? |
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Hello,
I have an '84 1.9 westie that I bought one year ago. I have spent the winter fixing her up:insalled rebuilt injectors from witch hunter, rebuilt throttle body from VC, I replaced the rusted out intake pipes and plenum with nice ones, new fuel lines+ filter, new vaccum hoses in eng compartment, rebuilt AFM from python, new gaskets on intake pipes ect. ect.
Anyway, it ran much better after my work exept for a slight wondering idle, variation of about 25 Rpm . Good power and acceleration, no complaints really.
But then I decieded to try and fix that unsteady idle and time the engine.
I read that most bad idle is from timing so I bought a timing light and checked out what I had. My engine AT IDLE was timed to the tdc mark NOT the timing V. So I adjusted the diz at idle with the idle control bypassed. Got her adjusted only at idle.
Now the idle is Rock steady at 800 rpm BUT I have a bad lack of power on take off and I just stalled going up a steep hill near my house in 2nd gear that I had previously had zoomed right up with no problems!!
Should I have timed the engine at total advance like 10c says, was that my mistake?
Thanks |
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Jake de Villiers
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Joined: October 24, 2007
Posts: 1488
Location: Crescent Beach, BC
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| Posted: Thu May 10, 2012 4:01 pm Post subject: Re: After timing adj. lack of power, stall??? |
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| summer samba wrote: | Hello,
I have an '84 1.9 westie that I bought one year ago. I have spent the winter fixing her up:insalled rebuilt injectors from witch hunter, rebuilt throttle body from VC, I replaced the rusted out intake pipes and plenum with nice ones, new fuel lines+ filter, new vaccum hoses in eng compartment, rebuilt AFM from python, new gaskets on intake pipes ect. ect.
Anyway, it ran much better after my work exept for a slight wondering idle, variation of about 25 Rpm . Good power and acceleration, no complaints really.
But then I decieded to try and fix that unsteady idle and time the engine.
I read that most bad idle is from timing so I bought a timing light and checked out what I had. My engine AT IDLE was timed to the tdc mark NOT the timing V. So I adjusted the diz at idle with the idle control bypassed. Got her adjusted only at idle.
Now the idle is Rock steady at 800 rpm BUT I have a bad lack of power on take off and I just stalled going up a steep hill near my house in 2nd gear that I had previously had zoomed right up with no problems!!
Should I have timed the engine at total advance like 10c says, was that my mistake?
Thanks |
I don't know about tencent, but I've always had better-running engines when timing them to total advance rather than at idle. I bet that's what he's talking about too.
_________________
'84 Vanagon GL 1.9 WBX
'86 Westy Weekender Poptop/2.5 Subaru/5 Speed Posi/Audi Front Brakes/16 x 7 Mercedes Wheels - answers to 'Dixie'
http://sites.google.com/site/subyjake/mydixiedarlin%27
www.crescentbeachguitar.com
www.thebassspa.com |
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Ahwahnee
Samba Member
Joined: June 05, 2010
Posts: 3068
Location: Mt Lemmon, AZ
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| Posted: Thu May 10, 2012 4:17 pm Post subject: |
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| I time my 84 using what you call the 10¢ method -- in fact I used his suggestion of making a mark 40° (2") CW from the V to indicate 35° BTDC all-in rather than rely solely on the timing light dial. |
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summer samba
Samba Member
Joined: July 03, 2011
Posts: 57
Location: East coast
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| Posted: Thu May 10, 2012 4:36 pm Post subject: |
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Thanks
I have the info explaining timing at 35 deg advance.
I already made the mark 2" from tdc on my pully.
I will try that tomorrow.
Is the tach on my van's dash accurate enough for timing purposes? |
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summer samba
Samba Member
Joined: July 03, 2011
Posts: 57
Location: East coast
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| Posted: Fri May 11, 2012 1:03 pm Post subject: |
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Just thought i would update.
I followed the method of timing a 1.9 found in the best threads
stickey under "timing".
Went great, just test drove and good power! rock solid idle!!
Thanks for your help
And thnaks to the Samba!!!!!!!!!!  |
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Wildthings
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Joined: March 13, 2005
Posts: 19922
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| Posted: Fri May 11, 2012 1:19 pm Post subject: |
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| Did you have your vacuum hose(s) off when you set the timing and have the digital idle stablizer bypassed? Best to set the timing at full mechanical advance. The timing for a 1.9 is 28° +/- 2° at 3800+ rpms |
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summer samba
Samba Member
Joined: July 03, 2011
Posts: 57
Location: East coast
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| Posted: Fri May 11, 2012 5:53 pm Post subject: |
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I set it at total advance, as detailed in the thread that I mentioned above.
It seems to work.
Everything connected, engine warmed up, mark on pulley 2" clockwise from U notch (35 deg. advance), rev to 3500, rotate diz to bring mark inline with case seam, bring back to idle , shut off engine, bipass idle stabilizer, start engine, adjust idle to 850+/- 50, shut off engine, reconnect Idle stab. check, done. |
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Mark
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Joined: January 20, 2003
Posts: 1499
Location: Sooke, BC Canada
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| Posted: Fri May 11, 2012 6:27 pm Post subject: |
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I had a similar issue with my '84 camper. Turned out the retard vac function was not working. I plugged the retard vac line, timed to total advance, giggety!
What worked best was trying this a few times, and seeing where the idle settled at. It purrs at idle, (when the lifters aren't acting up from inactivity) and pulls plenty strong without overheating, etc.
Think of it this way, do you drive at idle?  |
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 19922
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| Posted: Fri May 11, 2012 6:48 pm Post subject: |
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| summer samba wrote: | I set it at total advance, as detailed in the thread that I mentioned above.
It seems to work.
Everything connected, engine warmed up, mark on pulley 2" clockwise from U notch (35 deg. advance), rev to 3500, rotate diz to bring mark inline with case seam, bring back to idle , shut off engine, bipass idle stabilizer, start engine, adjust idle to 850+/- 50, shut off engine, reconnect Idle stab. check, done. |
By the book the timing for a 1.9 with Digijet is:
- 5 Initial
+10 Vacuum retard
+23 Centrifugal
+28 Total
If you are setting your timing at 35° you are off from spec by 7°. The vacuum advance adds another 14ish degrees so at 35°BTDC you would have almost 50° of total advance. That is kind of pushing it IMO.
I haven't read 10c post in a while, but the 35° spec is for a 2.1 Digifant. |
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Ahwahnee
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Joined: June 05, 2010
Posts: 3068
Location: Mt Lemmon, AZ
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| Posted: Fri May 11, 2012 8:11 pm Post subject: |
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It confuses me. Wouldn't the figure for retard be a negative? But then, does vacuum (retard or advance) operate fully at 3800 RPM?
In any case, if you set your mark at 35° BTDC and time to that mark I think all the other stuff is irrelevant -- i.e. idle stabilzer, vacuum hoses, retard, advance, etc are all doing what they are going to do and the result is 35°.
Maybe that is more advance than than the book value but I hear no ping and curiously when I drop it back down to idle I'm at 5° ATDC. |
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Wildthings
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Joined: March 13, 2005
Posts: 19922
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| Posted: Fri May 11, 2012 10:45 pm Post subject: |
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If you set your idle timing at 5° ATDC then as soon as you blip the throttle you get 10° added as the vacuum retard is overridden, so your base timing (assuming no vacuum advance) is now 5° BTDC. This would be the same initial timing as you would use if the retard can were bad or if you have the hoses removed. Add to this the 23° of centrifugal advance and you get 28° BTDC at 3800 rpm. This would be the timing with the hoses off. With the hoses on you would see about 42° total advance. The 35° of advance given in the Bentley is for a 2.1 with Digifant and not a 1.9 with Digijet.
You can not set your timing accurately at idle with the digital idle stabilizer hooked up. It varies the timing to try and stabilize the idle speed. Hard to set the timing if it is being changed all the time by the DIS. |
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Jake de Villiers
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Joined: October 24, 2007
Posts: 1488
Location: Crescent Beach, BC
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| Posted: Sat May 12, 2012 8:03 am Post subject: |
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| Ahwahnee wrote: | It confuses me. Wouldn't the figure for retard be a negative? But then, does vacuum (retard or advance) operate fully at 3800 RPM?
In any case, if you set your mark at 35° BTDC and time to that mark I think all the other stuff is irrelevant -- i.e. idle stabilzer, vacuum hoses, retard, advance, etc are all doing what they are going to do and the result is 35°.
Maybe that is more advance than than the book value but I hear no ping and curiously when I drop it back down to idle I'm at 5° ATDC. |
You have finally timed your engine correctly and it runs well, yes? Now you need to ignore the talk of vacuum retard and idle stabilizers and go and drive your van! 
_________________
'84 Vanagon GL 1.9 WBX
'86 Westy Weekender Poptop/2.5 Subaru/5 Speed Posi/Audi Front Brakes/16 x 7 Mercedes Wheels - answers to 'Dixie'
http://sites.google.com/site/subyjake/mydixiedarlin%27
www.crescentbeachguitar.com
www.thebassspa.com |
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Wildthings
Samba Member
Joined: March 13, 2005
Posts: 19922
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| Posted: Sat May 12, 2012 11:31 am Post subject: |
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| Jake de Villiers wrote: | | Ahwahnee wrote: | It confuses me. Wouldn't the figure for retard be a negative? But then, does vacuum (retard or advance) operate fully at 3800 RPM?
In any case, if you set your mark at 35° BTDC and time to that mark I think all the other stuff is irrelevant -- i.e. idle stabilzer, vacuum hoses, retard, advance, etc are all doing what they are going to do and the result is 35°.
Maybe that is more advance than than the book value but I hear no ping and curiously when I drop it back down to idle I'm at 5° ATDC. |
You have finally timed your engine correctly and it runs well, yes? Now you need to ignore the talk of vacuum retard and idle stabilizers and go and drive your van! |
Just went through and read Tencentlife's methods again for timing a 2.1 Dififant. Follow his methods and you get 40° BTDC at full advance not the 35° you guys seem to be claiming. Assuming when you are applying this to a 1.9 that you leave the vacuum hoses on and that everything in the vacuum system is working as per spec then you will end up with a full mechanical advance timing of 26° +/- two degrees. With luck if you vacuum advance gives 12° of advance you would be right on with this method at least at high idle in the parking lot, but if your vacuum advance is giving you 16° you are going to be off by 4° as you pull that hill in the truck lane. Of course if your vacuum advance isn't working correctly you could be off by way more than 4° when you have your foot to the floor. It would be much more correct to time your engine at 28° BTDC at 3800+ rpm, hoses off. That is where your engine wants to be so it can pass those truck instead of being passed.
As 10c says you can add a degree for every 1000 ft in elevation above 4000 ft.
10c methods work great for a Digifant with electronic advance, but with an old worm vacuum-mechanical distributor on a 1.9 you need to time is at full mechanical advance (static+mechanical) and not at total advance (static+mechanical+vacuum) nor at idle. |
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Ahwahnee
Samba Member
Joined: June 05, 2010
Posts: 3068
Location: Mt Lemmon, AZ
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| Posted: Sat May 12, 2012 11:55 am Post subject: |
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| Wildthings wrote: | | [...With luck if you vacuum advance gives 12° of advance you would be right on with this method at least at high idle in the parking lot, but if your vacuum advance is giving you 16° you are going to be off by 4° as you pull that hill in the truck lane. Of course if your vacuum advance isn't working correctly you could be off by way more than 4° when you have your foot to the floor... |
I would think vacuum advance would be about nil when you have your foot to the floor and you're going up hill.
I thought the whole advantage of vacuum advance was to give lots of advance when you're motoring along a level road fast with a light foot on the throttle. The idea being that under that circumstance the engine can tolerate more advance and the result is better mileage. |
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Wildthings
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Joined: March 13, 2005
Posts: 19922
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| Posted: Sat May 12, 2012 1:16 pm Post subject: |
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| Ahwahnee wrote: | | Wildthings wrote: | | [...With luck if you vacuum advance gives 12° of advance you would be right on with this method at least at high idle in the parking lot, but if your vacuum advance is giving you 16° you are going to be off by 4° as you pull that hill in the truck lane. Of course if your vacuum advance isn't working correctly you could be off by way more than 4° when you have your foot to the floor... |
I would think vacuum advance would be about nil when you have your foot to the floor and you're going up hill.
I thought the whole advantage of vacuum advance was to give lots of advance when you're motoring along a level road fast with a light foot on the throttle. The idea being that under that circumstance the engine can tolerate more advance and the result is better mileage. |
It is nil when you are going up a hill, which is why you should time at full mechanical advance verses timing it at idle or at total advance (which includes vacuum advance). 28° BTDC at 3800 rpms with the hoses off hits dead center to the factory specs for a 1.9L engine.
Time it at 40° BTDC or 35° BTDC or whatever these people keep dreaming up, with the vacuum advance maybe working but maybe not, and you will have no idea what the timing is when you are pulling a hill. |
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