Let's talk Fuel Pumps

[9dreizig]

Ok so the tracdog needs a new pumper.. Making a ton of noise,, burps and I can see the AFR's go lean.. 99.8% sure I need a new pump (already replaced the fuel filter). So here are my choices ,, get one from our host or EBS at the $300 range, 1 year warranty etc.. OR get a direct replacement (granted probably chinese in origin) with a one year warranty for $100!!
The old one (Cole930) says "just say no" to chinese crap, but I"m thinking I can buy three for that price..
What do you guys think ?

[IMR-Merlin]

Not sure about the pumps.... I've seen some stunters try to run some Brembo Knock off master cylinders on the stunt bike set ups, they'd work from time to time, but had a very high failure rate. I would say in a boosted car, reliability is worth the $200 price difference. Especially if the pump starts to partially fail and you go real lean and damage the engine.

[mark houghton]

The "Old One" speaks great wisdom, grasshopper.

But as long as we're talking fuel pumps, consider this CIS conundrum: If fuel pressure drops, then the air flow metering arm will deflect more, relatively speaking. That's pretty much what the WUR does by dropping the pressure ("control" pressure). So if you lose pressure, wouldn't you see a rich condition because the arm deflects more and allows more fuel to flow? Ahhhh....grasshopper....what's really happening when one loses a pump? Do we lose pressure, or is pressure sustained with only one pump running and all we lose is fuel volume to the injectors...thus, leaning as you've experienced?

Just an open ended question, as our 930's will run OK - to a point - with only one pump, but I wouldn't trust it on boost.

Wax on, wax off....

[jsveb]

I thought I rembered something about BOSCH pumps, that I read a while back. Something about two BOSCH pumps same specs except for the fittings. A little search and I found this (by:rotorhead):


First download this pdf http://apps.bosch.com.au/motorsport/downloads/fuelpumps.pdf it is the full specifications for Bosch motorsport fuel pumps.

My 1988 930 has a front pump with the number
0 580 254 967
and a rear pump 0 580 254 979
Your 1976 930 probably has the same setup. (For info the rear pump was also used on 928's and 944 turbo's I believe)

If you look at the motor sport pdf you downloaded you can see that there are two alternative pumps with the same specifications. The only difference is the inlet connection.

I purchased a 0 580 254 984 for $200 cheaper than the original and fabricated an adapter (Actually just a piece of 3/8" fuel hose clamped over the fitting).

I am sure that there are other alternatives out there such as pierburg, ACDelco or walbro. But I couldn't match the fittings/electical connections or mounting easily.

This thread gives you some part #:
930 fuel pump choice

Jesper

[JFairman]

Mark, I just don't subscribe to your theory at all.

The first thing Larry @ CISFLOWTECH does to raise the fuel delivery of a USA lambda 930 fuel head up to 25% more than stock, or a ROW 930 fuel head up tp 10% over stock.. is raise the system fuel pressure.

[cole930]

Kids

You can go with the $100 pump and see how long it lasts. The Bosch part numbers you need are (Front) 0-580-254-053 and 0-580-254-979 (Rear)

Here is a Bosch Pump chart to look over to compare specs you might cross reference different pumps and find one with comparable specs that's a lot cheaper.



Size is pretty flexible and fittings can be converted.

"The Old One"

[9dreizig]

Oh Mark I believe you are correct to a point. Yes it will go rich as evidence now as I put a new fuel filter in and am running rich (more fuel flow for same control pressure set point I believe). However there's a point were there's just no fuel when the pump burps at some point it must go lean.

Ok you guys convinced me I'm done dicking around with it, I'm going to shop around a bit and get the least expensive Bosch I can find..

[mark houghton]

Originally Posted by JFairman

Mark, I just don't subscribe to your theory at all.

The first thing Larry @ CISFLOWTECH does to raise the fuel delivery of a USA lambda 930 fuel head up to 25% more than stock, or a ROW 930 fuel head up tp 10% over stock.. is raise the system fuel pressure.

Jim, that was just a retorical/theoretical question....wondering what happens to AFR's when one fuel pump shuts down. I'm not asking for anyone to subscribe to what may be my flawed thoughts; rather, challenge it with factual CIS knowledge which - admittedly - you have a boatload more than I.

[JFairman]

well Mark.. it's real easy to find the truth. probably take less than 5 minutes.
there is a phone number on the cis flowtech website i posted the link to above.

just call Larry Fletcher and ask him...

he is a super nice down to earth alabama dude and he'll tell you some of the facts and he'll keep his major trade secrets to himself.
If he goes into the upper chamber modifications he does with you (which i doubt because you're not a customer, while i am) he'll seriously ask you not to post it on the internet and i won't do that either because of my respect for him and his business.

[polizei]

For what it's worth, Todd from Protomotive recommended that I go with a high flow Bosch 044 fuel pump. At the time we were talking 1.2 BAR boost with 944 Turbo injectors. Here's one on Amazon for $170:

Amazon.com: Bosch 044 Universal Inline Fuel pump: Automotive

Good luck!

[IDGAF27]

Originally Posted by polizei

For what it's worth, Todd from Protomotive recommended that I go with a high flow Bosch 044 fuel pump. At the time we were talking 1.2 BAR boost with 944 Turbo injectors. Here's one on Amazon for $170:

Amazon.com: Bosch 044 Universal Inline Fuel pump: Automotive

Good luck!

Pump on Amazon link looks egzact like one I received from our host, for double the price

[polizei]

Originally Posted by IDGAF27

Pump on Amazon link looks egzact like one I received from our host, for double the price

I didn't think our host sold the 044. Are you saying that Amazon is charging MORE than our host?

[JohnJL]

I like mine...

[A930Rocket]

Amazon looks to be cheaper.

Our host: Porsche 911 Fuel Injection (1989-98) - Page 1

[JFairman]

..everything can be found somewhere for cheaper than pelican, and some things are more expensive here than anywhere else.

that said, the customer service is better here than most everywhere else.

[iamchappy]

Ebay

bosch 044 fuel pump items - Get great deals on eBay Motors items on eBay.com!

[911st]

Learned Master:

When the stock fuel pumps are not performing to spec, I do not believe it is control pressure that adjusts to compensate.

I think it is the Fuel Distributor's ability to maintain the differential pressures between the upper and lower chambers that allows it to compensate and maintain AFR's.

However, reduced fuel pump performance might show up as lower system pressure. The FD's pressure differential will work to maintain AFR's probably up to the point where system pressure is reached then the AFR's will lean out.



There was one one very skilled engineer / C2 Turbo owner here that seems to find that by going to a 044 pump he did not go lean any longer.

In an effort to get more fuel up top he did the normal thing and tried to shim his system pressure and found no change in the upper rpm range. This was with a K27-7200 turbo maxed out on boost. Say a bit over 400 whp w the stock fuel dist but with lowered control pressure visa ve his custom fueler. The higher spec pump seems to cure his lean issue.

I think it is here:ELECTRONIC CIS fueling & BOOST control


Thus, if it was me I would look for a genuine 044 fuel pump. There are copies out there I hear.

[JohnJL]

Originally Posted by JFairman

..everything can be found somewhere for cheaper than pelican, and some things are more expensive here than anywhere else.

that said, the customer service is better here than most everywhere else.

I love Pelican for the great catalog, wizards and of course fantastic open forums.

I have noticed though service isnt what it used to be.

That being said, Wayne is still very accessible and again this forum is great. Its the reasons I still start my shopping here.

Oh, and I have to thank Wayne for the 3 engines I've built with his book by my side.