Fuel Pump Issue. Bosch 040

[Reflector]

Mate I've just been through this exact same problem over the last few months with the bosch 023 (040 big bro). First time pump last 3months but got noisier and noiser. Must've got a bad batch of fuel or something because it started leaning out big time and groaning badly. Fuel pressure dropped 2 bar. Took out the pump and the entire screen was filled with minuscule particles. Bought a new 023 whilst cleaning the old one and testing. Fixed the problem for about 1.5months then did the same thing. Exact same problem but I have suspicion my 'Submersible fuel line' was not what it was supposed to be. Replaced old pump, Was fine for 3 days then the same thing happened.

Long story short. The bosch intake fuel pumps are incredibly sensitive to debris. Seeing as they only have a screen mesh and no removable filter they are restricted to a flat surface area that once blocked, cannot allow sufficient fuel to be delivererd to the system. If you have a fuel pressure regulator with a gauge, check your current pressure at idle.

Solution - Install a walbro. Your current power figure could get by with a 255lph but if you plan on chasing more power (I have the same turbo @ 300rwkw) go for the 400lph to future proof. They're smaller, more efficient, easier to fit and have a larger surface area of pick up due to the removable filter sock.


Edit: Forgot to mention - I only fitted the walbro 400lph pump on Tuesday but the pump is dead quite, fuel pressure is up around 3bar idle (vacuum off) and it's the smoothest it's been in months. Will be pulling out the pump in a few months time to asses the sock as I still believe there's debris in my tank.

Edited February 9, 2014 by Reflector

[GotsWapan]

Thanks, Reflector. Will keep that in mind!!

[scotty nm35]

From what I've read thats an E85 specific pump. I don't have access to that fuel unfortunately.

There are petrol specific versions which are cheaper, I think I can get one for $160. Then there are the e85 compatible version which is suitable for both 98 and e85, $200. These run a sealed power plug.

[Reflector]

No worries mate. Also something else to consider - Due to the walbro being smaller and having a 45deg filter sock, it will fit a lot nicer into the cavity of the fuel tank allowing pick up a little further down the tank than what the bosch pumps permit. I've always commended bosch for having quality products but this time round, I can definitely say for an R33 Skyline application - Walbro > Bosch.

Edited February 9, 2014 by Reflector

[GotsWapan]

Might look into a walbro then if that's the case.

You think it will affect the tune much if I went with a walbro? Just got the car back from tuners a couple of days ago and my tuner is located 3hours away.

[scotty nm35]

Have you got a wideband installed? I would be checking the AFR's at wot just to make sure.

[GotsWapan]

No I don't have a wideband currently

[wolverine]

It shouldn't affect the tune if the pump was working when tuned. The regulator should keep the pressure where it should be.

Certainly a quick run with a wideband to make sure everything is fine is a good idea.

[Kinkstaah]

Changing the pump should do absolutely nothing if you're upgrading pumps. Keep in mind you'd want to check your wiring when using a 460L - I've had wires melt twice due to some shoddy worksmanship on mine.

[scotty nm35]

You mean speaker wires don't like 20 amp current draw Greg?

[Blackkers]

do those E85 460's really draw 20A?

I wouldn't trust the factory connections on the fuel lid with that kind of current. I'd be punching through the lid, feed some 25A wire and hot glue it. Does anyone bother doing that?

[Dose Pipe Sutututu]

do those E85 460's really draw 20A?

I wouldn't trust the factory connections on the fuel lid with that kind of current. I'd be punching through the lid, feed some 25A wire and hot glue it. Does anyone bother doing that?

depends how much boost you run, as the fuel pressure increases yes it will hit past 20AMPS

I had the factory 15amp fuse blow on me (when I first installed it), now I'm running a 25AMP fuse, through 2x relays & a 50W 0.3ohm resistor to mimic the FPCM

[scotty nm35]

As long as the connections are clean you should be fine.

Not sure I would trust hot melt glue, but the lid is fairly easy to re-make in alloy, then find some proper high current sealed plugs, or sealed bolts for connection like I used. Good opportunity to run teflon lines too.

[GotsWapan]

Don't know that I'll need the 460 fellas. I dont really plan going over 300rwkw at this point but will keep all the info in mind

[GotsWapan]

What sort of power are the standard size fuel lines hold up to?

[Blackkers]

I think Stao is running 500kw on e85 on his

Edited February 10, 2014 by Blackkers

[GotsWapan]

So plenty of room to move lol

[Bushy]

Had a similar problem recently at a track day with a Bosch 040 in tank pump, after about 3 laps I would get pretty bad fuel surge when revving out in a straight line even with a full tank, wideband showed it lean right out when this happened (up to 19 AFR). Also the fuel pump got noticeably louder as the day went on. Possibly due to the mesh filter being a bit blocked but I just replaced it anyway with a DW200 pump. I haven't driven it hard yet but noticed at idle fuel pressure now sits around 38psi whereas with the 040 it was about 30psi. I should be heading to the track on Monday so I'll report back if it fixed the problem.

New fuel pump seems to have fixed my surging issue.

[GotsWapan]

Ahh lovely. I've got another 040 on the way. Will see how she goes

[GH05T]

my 32 ate 2 bosch pumps,

some debris in the fuel kiled one randomly, usual noisy symptoms, surging ect.

replaced it and all was fine for a bit then that one went too.

i had miniscule particles in the fuel, took the tank out and had it cleaned, new pump (different brand) and all was well.

i couldnt even see anything on the mesh but its the tiny bits that got into the pump. kills them fast.

be wary of sticking another pump in, what killed it last time may take another out. check your fuel and tank, at least flush it, all new fuel, new fuel filter too.