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Kugelfischer Pump Specifications


dlacey
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Hey tii nerds,

 

Elsewhere we discussed some basic repairs of these injection pumps and touched on the topic of calibration... i wondered if anyone out there has any tii-specific setup specs for these Bosch/Kugelfischer/Schaefer pumps.

 

There's an old Pacific Fuel Injection video on youtube which gives some data:

Pump RPM Injection Volume/Cyl/1000Revs (ml) Cyl-to-Cyl range (ml)
500 12.7-14 3.8
1400 17.7-19.5 3.8
2800 54-56.7 2.0

In this video i didnt understand what throttle position was used for the measurements (I guess the different stops in the throttle lever have some role in calibration/setup)

 

I also have a test report from a pump I had serviced by Bosch Diesel Service in Singapore:

Pump RPM Injection Volume/Cyl/1000Revs (ml) 'Delivery Quantity'
500 50-52 Start
1250 34-36 Idle
3000 48-50 Full Load 

I think the 'Start' include full cold-start enrichment...the Idle figure doesnt make much sense......

 

In both tables the 2800RPM/3000RPM figures are roughly similar and my back-of-envelope calculation suggests that would give an Air-Fuel ratio of 1:15 (assuming many things) which is at least the right ballpark.

 

Anyone have any test reports of spec data to share?

 

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6 hours ago, dlacey said:

Anyone have any test reports of spec data to share?

 

Great info.  If only I understood it.   Let's see... ( Bosch / Singapore) turn the key and you get extra fuel to start the engine.  Once it starts the fuel consumption comes down as more air is introduced and the WUR is disabled.  Then you step on it and fuel consumption goes up by a reasonable amount.  Doesn't really jive with the PFI chart.

 

15:1 certainly seems likely.  I've always thought that the original settings were lean.

 

Sorry, I don't have any other pump data.  Maybe others do.

 

 

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What's missing in both of those tables is throttle position.

 

The 'cone' is metering based on 2 factors- revs and where the throttle is.

 

Since the throttle determines air, there's bound to be a big variation between 'closed' and 'open'.

 

t

from first principles

Edited by TobyB
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6 hours ago, PaulTWinterton said:

Maybe others do

Yes. Perhaps. In the archives. Defined by the P curves.

 

IIRC  that Turbo pump can deliver up to 900 CC's per 1000 strokes at full throttle/full boost.

 

But your gas in the tank won't last long........

 

Respectfully, the Covid / Caldor Fire Librarian.

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BTW, a local Porsche shop here has a few KF pumps that were fitted (or are spares) for 933 race cars. 

 

He has one that's new, never been mounted, and another that likely was not run. And and....

 

in case anyone is feeling adventurous they are for sale. :)

 

jXHwibG.jpeg

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14 hours ago, PaulTWinterton said:

 

15:1 certainly seems likely.  I've always thought that the original settings were lean.

 

 

 

There have been discussions of this in the past, but if one were to set up a 2002tii KF pump perfectly using original factory specs (which was the case when Gus at Pacific Fuel Injection rebuilt mine some 6-7 years ago, and sadly I do not have those specs) and also set up the remainder of the system using the basic settings in the factory BMW manual, then the resultant AFR would likely be lean thanks to modern oxygenated fuel.

 

However, the issue is further complicated by the proliferation of modern, inexpensive wideband oxygen sensor controllers and gauges. It must be stressed that even the best of these wideband O2 sensors are only capable of reading excess oxygen in the exhaust stream, which is of course post-combustion. It is a quite useful tuning aid, but not as accurate as a 5-gas exhaust analyzer, which gives a complete picture of the combustion process.

 

Almost anything that significantly affects combustion efficiency (besides an actual rich mixture) will result in excess oxygen in the exhaust stream, whether it be misfiring due to an ignition or mechanical issue (misfiring ALWAYS results in a lean AFR reading with a WBO2 system!!!) Also, while ignition timing will not affect AFR within the combustion chamber, significantly advanced or retarded timing from the ideal setting may affect the AFR reading at the WBO2 sensor due to imcomplete combustion (again, excess oxygen).

 

Apologies for the slightly off-topic excursion, but I feel this point needs to be emphasized when discussing AFR on vintage carburetor and MFI systems in conjunction with modern fuels and tuning techniques.

 

All that said, it seems like @PaulTWinterton has been doing some really cool things for 2002tiis during my absence from this board, which is great news for everyone :)

Edited by cda951
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An AFR of 15:1 ain't no big deal.  The E30 motronics used a narrowband O2 sensor and relied on it till the throttle switch clicked WOT.  That meant close to 14.7:1 +/- the narrowband switchover.  So the fuel was at or near 14.7:1 at all loads up to WOT.  At WOT the motronic changed over the WOT fuel table and ignored the narrowband.  I have read both tables from the chip for the M20

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Quote

Almost anything that significantly affects combustion efficiency (besides an actual rich mixture) will result in excess oxygen in the exhaust stream

Agreed.

 

Which is why you read the plugs, too, if things aren't adding up.

 

And a 2002 will run pretty well up to about 18:1 at very light loads with gobs of advance...

 

sorry about all the NoX, tho.

 

t

 

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