The 044 fuel pump came in the mail today as I was finishing up the oil return pump install. I installed it. I was very excited to try it out because the thing is huge. It makes 2 of the Walbro's and everything about it is big. Inlet, outlet, electrical studs...All the stats say it is a better pump than the Walbro. That's why I bought it.
The damn thing is a dog. It not only can't do the job the Walbro was doing, it does no better than the in-tank did by itself. I could literally take it out of the system and have the same fuel flow/pressure. I hope to Joe Pesci that I have a bad 044, if so I can send it back and try again, if not I am stuck with this POS. I thought I saw a flow comparison chart somewhere that had these 2 pumps in different arrangements the showed the 044 was better?
Anyone out there tried both or seen data comparing? Do I have a bad 044? Or does it just suck?
FYI: Walbro inlet-outlet fittings are 10mm o-ring but: I just found out today, after spending $11 on a 10mm to 1/8th npt adapter that the size of those 2 are identical and the thread almost identical. You can easily use an 8th npt with thread tape and no mods. I ran an npt tap into mine just to .....
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2005 GTO A4, $1600 DIY Master Power T-70 .96 A/R turbo in the rear, HPT, Nitto NT-05's, and E-85. 7.54@104 8th mile on 2.0 60ft street tires 15 psi. 580/660 wtq
Last edited by ericwilloughby : 10-31-2009 at 10:49 PM.
This may be part of the problem too. I friend of mine had an A1000 installed in his GTO buy a shop in SW Florida. He kept getting cavitation and poor delivery. He called Aermotive and found out they installed the damn thing bassackwards. They said the filter needs to go in front of the pump. They said the A1000 can push all day long but doesn't do very well on the suction side. With the filter being between the tank and the pump, it was causing too much restriction for the A1000.
Just somethint to think about
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This may be part of the problem too. I friend of mine had an A1000 installed in his GTO buy a shop in SW Florida. He kept getting cavitation and poor delivery. He called Aermotive and found out they installed the damn thing bassackwards. They said the filter needs to go in front of the pump. They said the A1000 can push all day long but doesn't do very well on the suction side. With the filter being between the tank and the pump, it was causing too much restriction for the A1000.
Just somethint to think about
in series was never intended to be run IN FRONT of a stock style filter.
MY suggestion:
By pass the intank filter. And try it again, if its fine, than add a filter after the external pump.
You should always have a filter before and after a large pump like that. You just need to make sure it is not some stupid OEM filter, you need a large one that does not impede flow.
This may be part of the problem too. I friend of mine had an A1000 installed in his GTO buy a shop in SW Florida. He kept getting cavitation and poor delivery. He called Aermotive and found out they installed the damn thing bassackwards. They said the filter needs to go in front of the pump. They said the A1000 can push all day long but doesn't do very well on the suction side. With the filter being between the tank and the pump, it was causing too much restriction for the A1000.
Just somethint to think about
Pre filters are usually 50 micron range. Not enough to restrict flow, but able to keep rust and grit from damaging the pump. A final filter should be in the 5-10 micron range.
BTW did you replace your external walbro, with the Bosch? or did you replace the in-tank Walbro with the bosch?
I replaced the external Walbro with the Bosch. There is an in-tank Walbro feeding the external. I know I must have a bad or weak pump because all other factors are the same. Lines, filters, supply pump...It just sucks that at full flow on the 60# injectors I actually have the same pressure with the Bosch that I do without it in the system. 3 bar. The Walbro made 4 bar. I got another Bosch yesterday, I'm going to test its flow under various pressures before I bother installing it in the car. Doing that now.
If the two pumps are in series without a surge tank, the Bosch is limited by the output of the intank pump. Moreover, if the regulator is still in the bucket, that's creating problems for you too. The return line has to go back to the original bypass port in the bucket once the regulator's been removed in order for the venturi to keep the bucket full. See B727pic's setup for the correct plumbing.
Last edited by mistermike : 11-06-2009 at 11:46 AM.
If the Bosch was being limited by the intank pump then the Walbro wouldn't be putting out 1 bar more than the Bosch. All other things in the system are equal. I installed the second Bosch today and had the same disppointing result. The Bosch 044 simply is not as good a pump as the much smaller and cheaper Walbro 392. Everybody says its better, flows more..and at higher pressure. if they are right then my supplier has a lot of bad pumps?? I'm done wasting my money and time on the 044 thats for sure.
Putting a bigger pump inline with a smaller pump in the bucket is just about worthless. Parallel those pumps and then you are getting somewhere. Good luck getting the factory regulator to bypass that much fuel however unless you put the 2nd pump on a hobbs switch.
I see what your doing. I just done see how the Bosch can put out more than the Walbro is supplying. Thats your limitation. I dont think you are solving anything with the way you have it now.
The second pump is on a hobbs switch set for 6 psi boost. There is no regulator, except for the one in the tank, there is no return.
The Bosch 044 simply is not as good a pump as the Walbro. Or I have 2 bad 044's.
Your problem is that the bosch is sucking dry the other pump at a much faster rate, than an external walbro. Thats why your fuel pressure dies out sooner than with the walbro.
The bosch pumps are better than the walbros.
PS, I've made over 700WHP on a turbo I4 on 2 in-series Walbros (one in tank, one external.) < the key thing was that we removed the factory fuel filter/line and ran a 3/8ths aluminum line towards the fuel rail.
Knowing that your 2 in series Walbros worked just fine and supplied adequate fuel, and the only thing different is the 044 in place of the GSL 392, it has to be one of a few things IMO:
1. Bad 044
2. Bad electrical connection
3. Crumpled or pinched fuel sock on the in-tank Walbro. Possibly due to in-adequate flow capability.
As someone suggested earlier, pull the tank (again), remove the sock and re-test.
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Quote:
Originally Posted by jamesbiz...
how big is your deck? Mine has mold all over it and I've been thinking of getting a new one.
The intank flows more than its rated for because there is little back pressure on that pump. Most of the work/load is on the external. Ill check the pressure inbetween the 2. I'm curious.
Quote:
Originally Posted by Oh4GTO...
I see what your doing. I just done see how the Bosch can put out more than the Walbro is supplying. Thats your limitation. I dont think you are solving anything with the way you have it now.
Maybe I'm wrong and there isn't enough inlet flow and the 044 is cavitating. A check of the inlet pressure will solve the question.
If it is that, and you can't solve the restriction, you could drop the voltage to the 044 just enough to stop it from cavitating. A band-aid, yes.. But it would work.
I had more pressure/flow with the walbro. Ill find a t and plumb in a gauge on the inlet and verify there is inlet pressure to be sure. But I am tired of messing with it.
For sale: 044 with -6 fittings $140. 2 minutes run time on it.
Last edited by ericwilloughby : 11-06-2009 at 09:45 PM.
I had more pressure/flow with the walbro. Ill find a t and plumb in a gauge on the inlet and verify there is inlet pressure to be sure. But I am tired of messing with it.
For sale: 044 with -6 fittings $140. 2 minutes run time on it.
If you remove your factory intank fuel filter, not the sock btw, the actual filter, you probably wouldn't even have needed the 044.
I agree with NicD. The problem's not the pump, it's the implementation. People use 044's all the time with great success, but not hooked up as you describe. They can't all be wrong.
You've never seen my pump. You don't know if it's off a bad lot or not. I know one thing for sure. I have 2 of each, (2)044 and a Walbro in-tank and a Walbro external, and the Walbro is hands down better.
I did some very basic testing of both pumps today. Here are the results.
Walbro in-tank running through the filter and factory lines to the engine bay. Free flow: 315 LPH. Bosch pulling 2 feet from gas can -6AN line no filters no outlet restriction: 258 LPH
I wish I could have tested the External Walbro but it's now my oil return pump and I don't want to take it off to test it.
None of this is as important as the next test. On the car in running configuration with a gauge on the inlet/suction side.
Last edited by ericwilloughby : 11-12-2009 at 03:05 AM.
Damn AN fittings. It's a PITA to find these things. I'm looking for a T so I can plumb my fuel gauge into the suction side of the External pump. To see if it is pulling more than the in-tank can provide. I stopped at 6 places on Sat to get one with no luck. I got one today at the ONLY serious fitting place in town. It seems that the -6 and -12 are the only AN fittings that have a different size thread than there 45 degree brass counterparts. Figures. Anyway, on to the testing.
So far, with just a short spurt into 2nd gear with 10 psi boost I have 35 psi on the inlet side of the pump, 044. I'll do a full pull 120 MPH run on the way to work tonight but I'm quite confident that there is plenty of flow into the External pump. I think the thing is either not what everyone says they are or mine are just rejects.
2005 GTO Owner
