Diesel Pulse Adapter Info Thread

[vanbcguy]

A bit different from the ones they are selling now... Pic of mine in post #107 of this thread.

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[ORCoaster]

The one in Post #107 is the same one that came with the MAC tool I have on loan from another forum member.  Fabricated for more on and off applications I think.  Temporary for timing purposes not hard install as the tach would normally be on long term. 

Can't really re tool it either.  I like the simple two bolts and done application myself.  I can touch the MAC sensor wire to the tach sensor and get better results than if I use the supplied adapter. 

[vanbcguy]

The line clamp is suitable for permanent installation (that's what they sell it for after all) but the electrical connection is definitely lacking for anything other than occasional use.

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[ORCoaster]

OK, Twas sunny and very nice in the driveway today so I pulled out the optical and the pulse adapters and the timing light.  Also dug out the timing dial gauge and all the needed sockets to do a multitude of timing setups.

I started with my base setting of 85 on the dial gauge just to test out the process.  That being set the timing to the desired dial mm number, Spin engine by hand and recheck setting.  Then pull the dial off and set it up to run and take two measurements.  One with the Pulse adapter located about 3/4 of an inch above the injector nut and the other with the Optical (Lumy) adapter.  I worked up the scale to 110 mm and then picked up the 70 and 80 measures on the bottom.  Once I had all the readings I wanted I rest the timing to 88 as per label on the strut.  

The base setting I had 85 mm was giving me 33 mpg in the stop and go city traffic on my short 3 mile jaunts to work.  Temps in the 40s generally during that time.  And ran the car for 450 miles between last fillup.  I added an extra five gallons to the tank some time in March.  

So the results are charted below and I just have to wonder why my pump does not get down to the 12 degree mark that I was expecting at the lower settings.  Or at the base setting for that matter.  Perhaps my internal IP pressure is too high, and I am running some advance at idle al the time?   I have read that one might need to run the idle at 1000 RPM doing this sort of thing but I kept mine in the 840-870 RPM range.  On the chart the red line is the Pulse adapter and the left axis is the scale, on the right is the Optical readings per mm setting.  I threw in the linear trend line to see how well it lined up and to allow others to perhaps get to the numbers one would expect to be here.  I am not sure why there is that stairstep effect going with the optical readings.  Maybe I was not aligned with the pointer dead on.

Just the same a lot of time to make all the adjustments and double check all the process.  

Open for discussion on what we can learn here.  

[TylerDurden]

Nice work.

Couple thoughts... what is the pop pressure on the injectors?

WRT the reading at low settings, maybe the tach pickup is not the correct polarity? If the timing instrument is designed to register when the line relaxes, the polarity of the element in the pickup would be critical, no? Whereas with the tach, polarity wouldn't necessarily matter.
 
"If the acquisition circuitry is designed to capture a specific polarity of pulse, it will be necessary to define the
direction of the force and the desired polarity of the output signal in order to guarantee the device will
consistently work in the desired application. "
http://www.digikey.com/Web%20Export/Supplier%20Content/PUI_668/PDF/PUI_UsingaPiezoBenderasaSwitch.pdf?redirected=1
(End of page 2)

[ORCoaster]

Pop pressure on injectors is not verified and may be some of my smoke on heavy throttle, like between 2nd and 3rd.  I did find a small mechanics shop that specializes in foreign cars that has a pop tester on his bench but he says he doesn't rebuild them anymore.  He just sends them to Portland.  But he did offer to take all the injectors I have, 12 of them and tell me which ones would need rebuilding and which were in spec.  I thought about offering to buy the pop tester but didn't at the time.

Interesting on the polarity thing.  I have not read that before but will see if it makes any difference today.  I have two of them, one for the pulse adapter and one for the Tiny Tach.  Which was the one I used as it clamps tighter than the modified 1/4 on that is in the adapter kit.  I was also thinking that position on the line wouldn't matter either but just for grins I may try moving in from the injector to the back of the IP.  It shouldn't change as the pulse is the same down the line correct?

I also have a pressure gauge on the IP.  I may pull that regualtor out and tap the pin out and reset it at a lower pressure at 1000 RPM.  And since I have two gauges that read pressure, oil and IP.  I might see if the IP gauge is off at all.  Yeah, trying to work out the variables.

OK, till this evening then. 

[vanbcguy]

I bumped my timing from 1.30 up to 1.38mm today. I've noticed some smoke that was a little lighter than I was expecting. After I changed the battery in my pulse adapter (left it on last time I used it -  Doh) it measured at exactly 10 degrees versus 8 degrees when I had it at 1.30mm. So with my pump and injectors anyways 0.08mm equals 2 degrees.

Oh and my engine is running noticeably smoother... :-)

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[Toby]

Hhmm..... Maybe because they all have a different sweet spot?

[vanbcguy]

Not sure what you are implying?
I started initially at 1.40. To me the engine sounded extra diesely, though I was moving from an IDI to a DI with monster injectors. I backed it off to see if I liked how it behaved better. Answer was NOPE, so I advanced it upwards again.  I never took a reading at 1.40 previously, I just assumed it was probably too advanced. Thanks to my tester I can now say it was actually just a hair over 10 degrees which is a totally fine setting.

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[bajacalal]

Not sure what you are implying?

I think that two identical engines may actually run differently at the same injection timing setting, because their respective injection pumps are not actually perfectly identical, and vary slightly because of differences in wear and calibration.

[vanbcguy]

Yup, that's the whole point of the pulse adapter. All of those variables are moot since you are measuring the actual start of injection rather than the plunger position.

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[745 turbogreasel]

Except they are measuring it at peak HP  somehow.

[TylerDurden]

Somehow is maybe (?):


That '79 is of course a 1.5L, with 125bar injectors and .83mm static timing.

The 1.6 stickers can vary depending on D or TD and ECO.

[theman53]

Except they are measuring it at peak HP  somehow.

I took it as "for this HP time it to____ with the timing light"


Also, in the pics above I do not see a timing spec for the timing light, just the mm gauge style, so they are kind of irrelevant to this thread.

[TylerDurden]

I took it as "for this HP time it to____ with the timing light"

Also, in the pics above I do not see a timing spec for the timing light, just the mm gauge style, so they are kind of irrelevant to this thread.

If it were as simple as "time it to ___ with the timing light", why would VW change the spec for the next decade or more?