| Author |
Message |
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
|
 Posted: Sat Aug 13, 2022 9:33 pm Post subject: Re: 12mpg from a 2.1 - what to look at? |
 |
|
| The rotor looks to be running way low compared to the cap. Check part numbers to be sure they both are correct for you distributor. |
|
| Back to top |
|
 |
Abscate
Samba Member
Joined: October 05, 2014
Posts: 22648
Location: NYC/Upstate/ROW
|
| Posted: Sun Aug 14, 2022 3:35 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
Replace that rotor. Replace the cap too. With that much arcing, the cap will also be shot
_________________
.ssS! |
|
| Back to top |
|
|
djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32598
Location: Reading Pennsylvania
|
|
| Back to top |
|
|
Pchill2
Samba Member
Joined: November 19, 2021
Posts: 405
Location: Georgia
|
| Posted: Mon Aug 15, 2022 5:14 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| vanis13 wrote: |
Thanks for the leads... Went down the rabit hole of coolant temp/ECU/gauge writeups this morning...yikes! A lot there to know with that.
Additional data ...."tuneup" done 6k miles 3yrs ago. The 12mpg started more recently
From the suggestions so far
Tail pipe clean, no excess soot. Actually no soot at all
A little arcing on the rotor tip. Cleaned with sandpaper. Cap looked good. Notice the circular wear pattern on the center spin point. Almost as of it was in there crooked. I seated it well. There was some spring in the distributer shaft - when I pressed rotor ask the way down whole shaft popped up 1/8?". Is that normal?
Plug condition in firing order
|
Your gap looks rather large. #2 looks pretty lean.
Hard to tell what's wrong with the rotor but it looks like it might need to be cleaned up with a little bit of sandpaper. how does the distributor cap look?
_________________
87 Syncro Westy
Honda K24 swap |
|
| Back to top |
|
|
vanis13
Samba Member
Joined: August 15, 2010
Posts: 3094
Location: ABQ NM USA.... Except when not
|
| Posted: Tue Aug 16, 2022 12:29 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
1 - replaced spark plugs with NGK 1263 per tencent
2 - ordered cap and rotor Bosch, Interestingly the current cap is pristine even though the rotor looks charred (pic above)
3 - ordered new temp and gauge sensors UltraPower/cheap. If you know the ohm reading standards for the gauge sensor, can you please post them in this thread https://www.thesamba.com/vw/forum/viewtopic.php?p=9911177
Gauge is barely at LED even when stage 2 fan comes on.
If the current ones test fine and are a good manufacturer will keep them otherwise I'll roll the dice on long term function on the cheap ones (if they test fine).
4 - ordered 87deg tstat Wahler Which hoses are best to IR temp gun to check Tstat function without taking out T stat? I'll test the new one and will test old one too, just want to pre-test temps before I pull it apart. Seems like the hose coming in the left and the hose coming out the right were similar temps even under 185
5 - 85/93 radiator fan switch Meyle. how does one interpret this temp range specified as 85-74/93-82c? stage 1 turns on at 85 off 74 stage 2 on at 93 off at 82 (so stage 1 will be on?) running it today while charging AC Stage 2 turned on even though temp gauge never got above LED (hence #3 above)
6 - re:3,4,5 I'm considering installing a temp gauge la http://texasvanagons.com/adding-a-water-temp-sender/ that will give me actual numbers since I can't tell the coolant temp from the dash gauge nor can accurately test the temp sensors on the vehicle w.o knowing the coolant temp. ... thoughts?
7 - what's the O2 sensor test for this vehicle (1991 2.1)? the only thing I found in Bentely is a open/closed test.
Thanks for ya'll's help.
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
|
| Back to top |
|
|
crazyvwvanman
Samba Member
Joined: January 28, 2008
Posts: 9923
Location: Orbiting San Diego
|
| Posted: Tue Aug 16, 2022 2:31 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
You have missed a big piece of the "puzzle" regarding your radiator fan behavior.
Your model has a 3 speed fan setup, not 2 speeds.
The A/C system controls a MIDDLE speed that is pretty high.
The dash temp gauge reading has nothing to do with the MIDDLE speed.
The MIDDLE speed is triggered only by high FREON PRESSURE in the A/C system.
The A/C system cycles LOW and MIDDLE radiator fan speeds for the needs of the A/C system, regardless of engine coolant temp.
The HIGHEST rad fan speed is triggered only by high radiator temps and this mode also disables the A/C compressor to help protect the engine from overheating.
Mark
| vanis13 wrote: |
......
5 - 85/93 radiator fan switch Meyle. how does one interpret this temp range specified as 85-74/93-82c? stage 1 turns on at 85 off 74 stage 2 on at 93 off at 82 (so stage 1 will be on?) running it today while charging AC Stage 2 turned on even though temp gauge never got above LED (hence #3 above)
...... |
|
|
| Back to top |
|
|
bridgetroll13
Samba Member
Joined: December 21, 2006
Posts: 177
Location: St. Georges, Delaware
|
| Posted: Tue Aug 16, 2022 3:44 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
Check the distributor shaft for excessive play. That mark on the rotor suggests there is a problem.
Erik |
|
| Back to top |
|
|
vanis13
Samba Member
Joined: August 15, 2010
Posts: 3094
Location: ABQ NM USA.... Except when not
|
| Posted: Tue Aug 16, 2022 5:32 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| crazyvwvanman wrote: |
You have missed a big piece of the "puzzle" regarding your radiator fan behavior.
Your model has a 3 speed fan setup, not 2 speeds.
The A/C system controls a MIDDLE speed that is pretty high.
The dash temp gauge reading has nothing to do with the MIDDLE speed.
The MIDDLE speed is triggered only by high FREON PRESSURE in the A/C system.
The A/C system cycles LOW and MIDDLE radiator fan speeds for the needs of the A/C system, regardless of engine coolant temp.
The HIGHEST rad fan speed is triggered only by high radiator temps and this mode also disables the A/C compressor to help protect the engine from overheating.
Mark
| vanis13 wrote: |
......
5 - 85/93 radiator fan switch Meyle. how does one interpret this temp range specified as 85-74/93-82c? stage 1 turns on at 85 off 74 stage 2 on at 93 off at 82 (so stage 1 will be on?) running it today while charging AC Stage 2 turned on even though temp gauge never got above LED (hence #3 above)
...... |
|
That's for the clarification of 3 stages.
In this instance with this 1991 2.1 I was then experiencing experiencing stage 3 where the the AC system was shut down until the temp lowered.
If we modify the status report to indicate Stage 3 where I wrote stage 2. What does it do to the conclusions?
.....My personal van is a 83.5 which I believe has only 2 speeds even with AC stage 1 first rad fan switch temp and/or AC on. Stage 2 switch fan switch temp which turns off AC until it steps down to stage 1.
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
|
| Back to top |
|
|
vanis13
Samba Member
Joined: August 15, 2010
Posts: 3094
Location: ABQ NM USA.... Except when not
|
| Posted: Tue Aug 16, 2022 5:33 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| bridgetroll13 wrote: |
Check the distributor shaft for excessive play. That mark on the rotor suggests there is a problem.
Erik |
What is excessive?
How is it measured?
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
|
| Posted: Tue Aug 16, 2022 8:40 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| vanis13 wrote: |
| bridgetroll13 wrote: |
Check the distributor shaft for excessive play. That mark on the rotor suggests there is a problem.
Erik |
What is excessive?
How is it measured? |
Never measured it, but it isn't very much, <1/32 inch. Just lightly lift up and press down on the rotor. There are a series of shims on the distributor shaft and the distributor drive that affect the height, these shims have a history of failing and disappearing over time. If the one set of shims fail and the distributor isn't installed deep enough into its bore that will cause the rotor to run low. |
|
| Back to top |
|
|
vanis13
Samba Member
Joined: August 15, 2010
Posts: 3094
Location: ABQ NM USA.... Except when not
|
| Posted: Tue Aug 16, 2022 10:27 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| Wildthings wrote: |
| vanis13 wrote: |
| bridgetroll13 wrote: |
Check the distributor shaft for excessive play. That mark on the rotor suggests there is a problem.
Erik |
What is excessive?
How is it measured? |
Never measured it, but it isn't very much, <1/32 inch. Just lightly lift up and press down on the rotor. There are a series of shims on the distributor shaft and the distributor drive that affect the height, these shims have a history of failing and disappearing over time. If the one set of shims fail and the distributor isn't installed deep enough into its bore that will cause the rotor to run low. |
I'm concluding you mean vertical play.
There is no vertical play up.
There is 1/8" play down if I push. It bounces back up.
There is no side play.
Here is a closer pic of the rotor and the off-side wear pattern.
Also a shot of the distributor schematic. It notes "shims - note number and location" but doesn't specify quantity nor is there any other mention of shims even in the distributor installation section.
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
|
| Back to top |
|
|
RBEmerson
Samba Member
Joined: November 05, 2011
Posts: 2108
Location: SE PA
|
| Posted: Tue Aug 16, 2022 10:57 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
KISS! Do the plugs, wires, cap & rotor, fuel filter (air filter done IIRC), and throw some Sea Foam in the gas. Change the O2 sensor? Can't hurt, might help. (BTW, "mystery gas" from Billy Bob's Fill 'n' Fish? Maybe not).
If the basics don't tidy things up, then look for harder-to-answer problems.
Past that, is it the vehicle or the driver? Could be the driver's developed a change in driving.
_________________
Lord, give me coffee to change the things I can change, and wine to accept the things I can't change. |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
|
| Posted: Tue Aug 16, 2022 11:17 am Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
The shims and washers limit the axial play, 1/8" of play would mean that something is missing.
Your rotor looks to be either very old or to have seen some kind of trauma. It certainly needs to be replaced. The rotor and cap need to match. Just because the cap will latch down to the distributor body does not mean it is the correct one.
Samba member "Glen" can supply you with new shims and washers, if my memory is correct. |
|
| Back to top |
|
|
vanis13
Samba Member
Joined: August 15, 2010
Posts: 3094
Location: ABQ NM USA.... Except when not
|
| Posted: Tue Aug 16, 2022 12:29 pm Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| Wildthings wrote: |
The shims and washers limit the axial play, 1/8" of play would mean that something is missing.
Samba member "Glen" can supply you with new shims and washers, if my memory is correct. |
how/where can I learn more about this? Doesn't seem to be covered in Bentley.
"glen" has no posts last active in 2006 https://www.thesamba.com/vw/forum/profile.php?mode=viewprofile&u=16713
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
|
| Back to top |
|
|
vanis13
Samba Member
Joined: August 15, 2010
Posts: 3094
Location: ABQ NM USA.... Except when not
|
| Posted: Tue Aug 16, 2022 12:39 pm Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
How to test O2 sensor on THIS vehicle?
Re: #7 - what's the O2 sensor test for this vehicle (1991 2.1)? the only thing I found in Bentely is a open/closed test.
| Californio wrote: |
| If I remember right there's a heating circuit on the O2 sensor on later models and if this isn't working, it could make the engine take longer to idle correctly. Easy to test. |
How?
Found this though insure which terminals to check in which way (connected, pierce wire? Disconnected?....Can’t really get to the backside of the connector since it is rubber covered.)
https://itstillruns.com/test-sensor-5193043.html
| ThinkingD wrote: |
| Maybe an exhaust leak/crack before the o2 sensor causing it to run rich by allowing fresh air into the system pre-o2 and making the ECU think it is running lean. |
Before the O2 sensor, only tiny leaks at the J pipe and one of the joining connections by blowing shopvac into it. Leaks look WAY bigger with the bubbles.
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
|
| Back to top |
|
|
vanis13
Samba Member
Joined: August 15, 2010
Posts: 3094
Location: ABQ NM USA.... Except when not
|
| Posted: Tue Aug 16, 2022 6:33 pm Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| vanis13 wrote: |
How to test O2 sensor on THIS vehicle?
Re: #7 - what's the O2 sensor test for this vehicle (1991 2.1)? the only thing I found in Bentely is a open/closed test.
| Californio wrote: |
| If I remember right there's a heating circuit on the O2 sensor on later models and if this isn't working, it could make the engine take longer to idle correctly. Easy to test. |
How?
Found this though insure which terminals to check in which way (connected, pierce wire? Disconnected?....Can’t really get to the backside of the connector since it is rubber covered.)
https://itstillruns.com/test-sensor-5193043.html
| ThinkingD wrote: |
| Maybe an exhaust leak/crack before the o2 sensor causing it to run rich by allowing fresh air into the system pre-o2 and making the ECU think it is running lean. |
|
Samba FAQ to the rescue! https://www.thesamba.com/vw/forum/viewtopic.php?p=3444744#3444744
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
|
| Back to top |
|
|
Wildthings
Samba Member
Joined: March 13, 2005
Posts: 50338
|
| Posted: Tue Aug 16, 2022 6:55 pm Post subject: Re: 12mpg from a 2.1 - what to look at? |
|
|
| vanis13 wrote: |
| Californio wrote: |
| If I remember right there's a heating circuit on the O2 sensor on later models and if this isn't working, it could make the engine take longer to idle correctly. Easy to test. |
How? |
There is a plug to the left side of the engine compartment. Just trace the wiring bundle for the O2 sensor back into the engine compartment. |
|
| Back to top |
|
|
|
