Yes, another thread on these crappy pumps.


Some time ago, I posted a thread about rewiring the fuel pump so it could get full voltage from the battery. I did it and all seemed well.

Well turns out the pump still has the issue of slowly loosing fuel pressure the longer you drive it.

After long drives most of you probably notice the pump will get much louder. I happen to have a fuel pressure gauge mounted inside the car and the louder it is, the less pressure coming from the pump. I'd be almost everyone here using the walbro has the same issues as I do but don't have a gauge to realize it. Also if you have an AF gauge, you can see your engine will slowly run more lean.

The guys on the evo forums have the same issue with this stupid pump. They figured it is because the pump is heating up and slowly becomes weaker the hotter it gets. It uses fuel as cooling and since we have a return fuel system, each pass the fuel makes, it gets warmer and warmer.

I don't think my pump is fake. The orgional pump that came with my IP kit I replaced because of this problem. I couldn't drive past ~3 hours or so because I would run out of fuel pressure. The new pump from walbro did the same crap. I didn't think I was going to make it to the last fall colors because I nearly ran out of fuel pressure AGAIN after 6 hours of driving, I had to go into boost so my FPR increased fuel pressure enough to drive the damn thing.

So what do we do? Is there any other drop in fuel pumps aside from this crappy walbro pump that can't go for more then 4 hours on the road? Do we just keep replacing them until we get one that actually works? I'm betting everyone on this forum that uses this pump has the same problem whether you know it or not.

Also, what do your pumps sound like? In this youtube video, the author says the fake one is the second that he turns on. Mine sounds like the second one but the first one sounds like the crappy (fake) one...
[media]http://www.youtube.com/watch?v=7102yaOA2jk [/media]


Thoughts?

 

thats why i switched back to the stock intank pump and added a bosch 044 and surge tank......

 

get a supra pump to work. then it would be quiet too

 

When you say it does not provide enough pressure do you mean to even run at all or to go into boost?

 

funny, I was coming up on 3hrs and notices my car was running a touch leaner.............maybe 11.5 or 11.6 WOT as opposed to 11.1-3, or something like that.......

 

Would the KB BAP help with this? As it bumps the voltage up in case of a drop.

 

I use O2 feedback on my 1052U, it self adjusts within 10% of my map.

 

it makes sense that it would lower output as the pump gets hotter and the resistance increases in the motor. My pump will whine as well after longer drives and sometimes in hotter weather. It's nice to have that gauge! What other pumps flow well that are also relatively inexpensive? Supra pump? EVO 8-9 pump? A newer D.I. pump from something like a 335 or Ford eco-boost?

 

To run the engine!

After 6 hours, the engine was cruising on the highway around 15-16 A/F

I had to go into light boost so my FPR would increase fuel pressure enough to keep the engine from stalling. Luckily, we were within 20 minutes of the hotel.

I'm always nervous driving around with this pos pump....

 

IIRC, the BAP increases voltage relative to boost (similar to a FPR) so the issue would still exist