Printable Version of Topic
Click here to view this topic in its original format
914World.com _ 914World Garage _ Timing 73 2.0L D-jet
Posted by: steuspeed Apr 11 2021, 06:48 PM
In pursuit of hunting idle, I have done the following. New plugs and wires. All new vacuum lines. Reset the ECU to factory notch on the knob. With a mirror, I found two straight notches on the back edge of the fan. The first one lined up with the #1 plug on the distributer and the dizzy notch mark. I believe that is TDC? It was (red) so I marked red on the front edge of the fan where I can see it through the hole with my timing light. The second one ~4 blades further (no color) I marked yellow line on the front edge. Removed both vac lines from the dizzy. Run the engine up to about 2K and I can get the red to line up with the notch. As the RPM goes higher it walks toward the passenger side out of sight. Pertronix rotor no points.
Is seems to me the my yellow line should be lining up as per Hanes manual. What am I doing wrong?
EDIT: Okay, so TDC should not be the red, but the unpainted clear mark. The red is the 27 BTDC timing mark.
Posted by: saigon71 Apr 12 2021, 05:25 AM
In pursuit of hunting idle, I have done the following. New plugs and wires. All new vacuum lines. Reset the ECU to factory notch on the knob. With a mirror, I found two straight notches on the back edge of the fan. The first one lined up with the #1 plug on the distributer and the dizzy notch mark. I believe that is TDC? It was (red) so I marked red on the front edge of the fan where I can see it through the hole with my timing light. The second one ~4 blades further (no color) I marked yellow line on the front edge. Removed both vac lines from the dizzy. Run the engine up to about 2K and I can get the red to line up with the notch. As the RPM goes higher it walks toward the passenger side out of sight. Pertronix rotor no points.
Is seems to me the my yellow line should be lining up as per Hanes manual. What am I doing wrong?
On my 74, the white mark is TDC. The red mark is the advance you want.
You want the distributor hold down snug when you adjust timing, so it takes some effort to turn it.
The car needs to be revved to >3500 for full advance with the vacuum lines removed - this will give you full advance - I suspect this is where you are going wrong.
Regarding the hunting idle...Try running full rich (clockwise) on the ECU knob, turn it counterclockwise one notch at a time until it begins to hunt, then go back clockwise one notch. If full rich doesn't cure the hunting, you may need to install a ballast resistor, which were used on the 1973 model. Fiddle with this after setting the timing.
Good luck & keep us posted.
Posted by: TheCabinetmaker Apr 12 2021, 08:26 AM
Plug the vacuum lines that you removed, to set timing
Posted by: steuspeed Apr 13 2021, 06:12 PM
Okay this is exactly what I am seeing. The red dash is 27 BTDC and the clear/white ~4 blades to the right is TDC. (photo from Pelican) So the red mark is correct mark for timing at 3500rpm.
https://cdn6.pelicanparts.com/techarticles/914_timing/20impeller.JPG
Posted by: saigon71 Apr 13 2021, 08:05 PM
Yes. Set timing to the red mark while reving >3,500 RPM's with vacuum lines disconnected and you are good to go. 
Posted by: steuspeed Apr 13 2021, 11:39 PM
Okay, so I pulled the vac lines and plugged them. Turned the ECU knob to full rich. I can set the timing to the red mark like idle to 2K, then it move off to the right as I rev higher. The car starts on key turn. It idles high then comes down after about 1min, so air valve is closing proper. I tested it off car as well. It runs with a little buck/kick at low speeds. It's just not smooth. Get on it, and she goes pretty good. Hunting idle is still there. Inconsistent off throttle to idle speed. Any ideas?
I orders the MPS tune kit from Tangerine, so I will try and set that proper when it gets here. Mine has been tampered with by PO.
Should I swap ECUs? or Coils? Switch to stock point?
Posted by: DRPHIL914 Apr 14 2021, 08:16 AM
Okay, so I pulled the vac lines and plugged them. Turned the ECU knob to full rich. I can set the timing to the red mark like idle to 2K, then it move off to the right as I rev higher. The car starts on key turn. It idles high then comes down after about 1min, so air valve is closing proper. I tested it off car as well. It runs with a little buck/kick at low speeds. It's just not smooth. Get on it, and she goes pretty good. Hunting idle is still there. Inconsistent off throttle to idle speed. Any ideas?
I orders the MPS tune kit from Tangerine, so I will try and set that proper when it gets here. Mine has been tampered with by PO.
Should I swap ECUs? or Coils? Switch to stock point?
if hunting idle is still present you have a vac leak somewhere still OR the MPS is tuned too lean, this was my case with a rebuilt MPS not tuned correctly! this is why i installed a AF meter and O2 sensor in my Triad exhaust, you really cant tune that well without it, you can probably get close by rechecking plugs and just by feeling the idle change. - you will need the instructions of tuning the MPS if you do the rebuild.
-https://members.rennlist.com/pbanders/DJetParts.htm
Phil
Posted by: brant Apr 14 2021, 08:35 AM
I chased a hunting idle on a 2.0 djet for 3 years.
finally had the throttle body rebuilt (not cheap) but that was my problem
brant
Posted by: DRPHIL914 Apr 14 2021, 08:39 AM
I chased a hunting idle on a 2.0 djet for 3 years.
finally had the throttle body rebuilt (not cheap) but that was my problem
brant
@http://www.914world.com/bbs2/index.php?showuser=47 , good point, I had mine rebuilt too and that was an issue as well, throttle body, intake runners on both ends and the plenum too.
Posted by: steuspeed Apr 14 2021, 02:55 PM
-https://members.rennlist.com/pbanders/DJetParts.htm
Phil
Once the AAR valve closes the engine idle drops from 1600rpm running smooth down to 300 and hunts 300-800. I cannot get the idle higher with the idle screw all the way out. If the hunt swing drops low enough it dies.
I took out the MPS and it is part # 0 028 100 015 which does not match up with pbanders doc. The MPS in my 74 Outlaw is 0 028 100 001 which is another mystery. They should be ...037 and .. 043 respectively.
EDIT: ...015 MPS in this car is for Volvo 1800, 160 and 140 71-74
... 001 MPS in my 74 Outlaw is for VW Type 3 68-69 early style with one screw and no full load diaphragm.
Posted by: steuspeed Apr 14 2021, 02:56 PM
I swapped the coil out. No change.
Posted by: rjames Apr 14 2021, 04:12 PM
I'm betting it's the MPS. Especially if you don't have the right one for your car.
When you get the MPS tuning kit you ordered you'll probably be able to dial it in further so the idle doesn't hunt. However, you'll need to be able to know what your AFR is to dial things in correctly.
Did you already test the MPS to see if it holds vacuum?
Posted by: jcd914 Apr 14 2021, 10:21 PM
Okay, so I pulled the vac lines and plugged them. Turned the ECU knob to full rich.
I can set the timing to the red mark like idle to 2K, then it move off to the right as I rev higher.
The car starts on key turn. It idles high then comes down after about 1min, so air valve is closing proper. I tested it off car as well. It runs with a little buck/kick at low speeds. It's just not smooth. Get on it, and she goes pretty good. Hunting idle is still there. Inconsistent off throttle to idle speed. Any ideas?
I orders the MPS tune kit from Tangerine, so I will try and set that proper when it gets here. Mine has been tampered with by PO.
Should I swap ECUs? or Coils? Switch to stock point?
The bold text above does not sound like the timing is set correctly.
The red 27 degree timing mark needs to line up while the engine is held at 3500 rpm.
Jim
Posted by: saigon71 Apr 15 2021, 05:47 AM
Okay, so I pulled the vac lines and plugged them. Turned the ECU knob to full rich.
I can set the timing to the red mark like idle to 2K, then it move off to the right as I rev higher.
The car starts on key turn. It idles high then comes down after about 1min, so air valve is closing proper. I tested it off car as well. It runs with a little buck/kick at low speeds. It's just not smooth. Get on it, and she goes pretty good. Hunting idle is still there. Inconsistent off throttle to idle speed. Any ideas?
I orders the MPS tune kit from Tangerine, so I will try and set that proper when it gets here. Mine has been tampered with by PO.
Should I swap ECUs? or Coils? Switch to stock point?
The bold text above does not sound like the timing is set correctly.
The red 27 degree timing mark needs to line up while the engine is held at 3500 rpm.
Jim
Get the timing & dwell dialed in 1st.Posted by: Bleyseng Apr 16 2021, 08:53 AM
Ok I'll chime in - Do you have a matching 73 ECU (037) and 017 CHT plus the 270 ohm resistor? I see your MPS is completely mis-matched so get your FI parts to match first. Then if your MPS can be calibrated to 037 specs you will get it right.
Then to set your idle speed it must be done with the engine hot so after 15 minutes of driving you can finally set the idle mix and speed using the ECU knob and the air bypass screw. 
Posted by: steuspeed Apr 17 2021, 11:32 PM
So today I decided to turn that little screw on the MPS and see what it did. The Tangerine calibration kit is still not here and it's fabulous 80 degrees out this weekend. About a half turn and the idle is now over 1K, so dial it back with the idle screw. No more hunting!!! Okay, now able to adjust timing to red mark 27 BTDC perfect at 3500rpm. The car has never run this good in the 10 yrs I have owned it. Starts strong and instant on key turn only. Hopefully I can adjust this Volvo MPS to the correct spec for a 73 2.0L for an even finer tune.
Posted by: saigon71 Apr 18 2021, 06:39 AM
So today I decided to turn that little screw on the MPS and see what it did. The Tangerine calibration kit is still not here and it's fabulous 80 degrees out this weekend. About a half turn and the idle is now over 1K, so dial it back with the idle screw. No more hunting!!! Okay, now able to adjust timing to red mark 27 BTDC perfect at 3500rpm. The car has never run this good in the 10 yrs I have owned it. Starts strong and instant on key turn only. Hopefully I can adjust this Volvo MPS to the correct spec for a 73 2.0L for an even finer tune.
Great news! Enjoy the drive.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)