Mythbuster: continuing project thread of my 1303 '75

[Bruce.]

A few thoughs to be helpful.

If you can set up a voltmeter to measure the volts across the pump it will confirm if you have a problem with wiring (or a connector). If the volts drop across the pump when it is flowing lots of amps, there is another source of electrical resistance between the pump and the Bat/alternator.

I'm also guessing you have a genuine 044 from a known seller? Apparently there are copies on Ebay which look good but don't perform.

Is the supply to the pump (pipe sizes and tank port) big enough? A fuel pressure sensor at the 044 input would show if there is always positive pressure at the input. If the 044 has to suck the fuel at high flow rates, the output pressure would drop.

good luck!

[Wally]

Thanks Bruce!

I just removed the catch tank and Carter feed pump and now I can maintain my target lambda all the way to redline under 20 psi of boost. Now that was fun

You were probably close with the feed to the 044 not being optimal. The intake line is 1/2" internal from the tank to the feed pump, so plenty big, but entrence into catch tank is only 7mm internal, so almost half that size. For the low pressure Carter pump probably a little too much of a restruction to get to full flow.
Feed to the 044 itself from the catch tank is 1/2" or about -12 iirc, but if there's only one restriction...

Now the 044 sucking straight from the 1/2" from under the tank works well, but at higher boost, the rising rate pressure suffers a little and doesn;t follow the boost pressure quite. That leads me to believe the 044 is somehow running a little on the edge in my set-up.
For now it will do, but maybe a second pump may be wise in the long run.

Thanks for thinking along all!

[Wally]

Originally Posted by Bruce.

I'm also guessing you have a genuine 044 from a known seller? Apparently there are copies on Ebay which look good but don't perform.

Whats a 'known seller' worth these days huh?
The info in this link I recently found comparing a fake chinese copy 044 and a real one was really helpfull.
Just for the record: I have a real Bosch 044

http://trolltuner.com/?p=692