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Who has a Bosch 044 fuel pump?

Merli

By Merli,
in Engines & Forced Induction

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Merli Grand Master

Merli

Posted
Posted

I'm having troubles starting my car.

I've been told that because the Bosch 044 doesn't have a fuel return catch valve, fuel drains from the fuel rail back into the tank, and that's why I have to crank my car over 2-3 times before it'll start...

It's been suggested to me that I turn ignition on for 5 seconds, let the pump prime, then turn the car off again, then on again for another 5 seconds, and then crank it. Unfortunately this doesn't seem to help the situation.

Does your car do this? How do you get around the problem?

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Steve Grand Master

Steve

Posted
Posted

the 044 comes with a non return vavle, well mine did - just need a banjo fitting to go over it which you should be able to get from a speed shop.

Having said that, I know a guy who has a 044 and they (workshop) removed the non return valve when it was fitted, as its easier to get a hose tail connector - he hasnt had any problems that I know of, as I specifically asked if he had problems with it being removed.

sorry if thats not much help

meshmesh Mentor

meshmesh

Posted
Posted

Firstly, I don't know all the technicals and only remember the basics.. since going to the bosch 044 we initially had a similar problem, and in some case the car would not start for some time.

So here's what we did..

1) Checked the battery and found we had a shitty 280cc (good for suzuki swifts) replaced this with a maintenance free ~450cc battery [this helped a great deal]

2) Check that your connector thingo's to the bosch pump are securely attached, we ended up soldering them on. [this definately help fuel pressure]

3) An option we were told to try if we wanted to was add a relay.. [we have not bothered trying this yet, coz all is sweet now]

Overall, our problem is pretty much fixed, initally it was similar to you Merli, but now it's all sweet. Basically you need to prime the Bosch Pump, if it doesn't start "normally" on the first try, switch it off, turn it to ignition and let the pump prime for about 5seconds then it should start, otherwise do it one more time. I rarely have to do it more than twice.

Merli Grand Master

Merli

Posted
  • Author
Posted

thanks for the replies so far guys...

meshmesh, did you run a constant 12V straight from the battery to the pump, or did you use the original wiring which has a voltage stepper? I've got mine wired in with the standard wiring, as I was told that unless there's a problem with the standard wiring, it's best to use it as the voltage stepper helps prolong the life of the pump and adds reliability :confused:

I'm using an Optima Yellow Top, so there's no problem with the battery...

The other thing is, I can't hear the pump priming when I turn it to IGN... This is meant to be a very loud pump right? I can't hear it zzzzzzzzzz'ing whilst it primes itself like the HKS pump did in my old car...

Oh, and the report of the GT-SS is coming after it's been fully run-in and tuned :) So far, they're spooling at about 3500rpm but that's with the camshafts not dialed in at all... Cam gears are still on 0 setting. Should be able to bring boost on a little earlier :rofl:

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
thanks for the replies so far guys...

meshmesh, did you run a constant 12V straight from the battery to the pump, or did you use the original wiring which has a voltage stepper? I've got mine wired in with the standard wiring, as I was told that unless there's a problem with the standard wiring, it's best to use it as the voltage stepper helps prolong the life of the pump and adds reliability :confused:

The other thing is, I can't hear the pump priming when I turn it to IGN... This is meant to be a very loud pump right? I can't hear it zzzzzzzzzz'ing whilst it primes itself like the HKS pump did in my old car...

ok, 1, the bosch pumps, noisy as. The walbro are quieter, and i can still hear mine whining.

2, you need to run more power to the pump, the stock wiring dont get what the pump needs. I think once you do that you'll be fine.

But i still let mine prime for a few secs before starting.

Different pump, but aftermarket none the less

Amaru Veteran

Amaru

Posted
Posted

Check the wiring possibly... from what I have heard the factory wiring doesnt quite cut the mustard with one of these pumps (a few tuners have also told me horror stories of stock wiring burning out and catching on fire when used for such a large pump).

JimX Grand Master

JimX

Posted
Posted

I've never had a starting problem with my 044 even thought I thought I might due to the removal of the valve. I am concerned about my wiring burning out though. Where does it tend to burn through? In the top of the fuel tank cap? I should check it when the pump gets hot. It's quiet until it gets warm. On a long highway ride in the middle of summer I can hear it over the engine, and it's embarrassingly loud when I pull into a servo. But in winter it's almost silent, unless I do a lot of driving in which case it's somewhere between silent and embarrassingly loud.

Skyrine-Dave Mentor

Skyrine-Dave

Posted
Posted

Stick ya head in the boot and get someone to crank the car to ign so you can really try and hear the pump. If you cant hear it priming when its on IGN then there must be a problem with the way its installed or wired up.

My 550hp walbro is fairly quiet and you can hear it prime/building rail pressure for a few seconds before i crank it on. But i am thinking of putting a 044 inline with a surge tank incase teh walbro cant hack the new power/fuel requirements.

I also dont think it is wise to run a constant 12v power supply to the fuel pump. You really want the pump to lose power when the IGN not on. Ie in the event of an accident the pump wont continue to pump fuel all over the place.

Sydneykid Grand Master

Sydneykid

Posted
Posted

My 20 cents worth....

The 044 is designed to work at 13.8 volts all the time. So feeding it 6 volts doesn't sound like a particularly good idea to me. So I always run a relay, switched by the standard wiring and with power supply wiring back to the battery. I use a 30 amp fuse at the battery to make sure there are no short circuits. I have never had a problem with priming but I always run a non return valve if the pump is mounted in the tank. If it has a surge tank, then a non return valve isn't really necessary.

Hope that helps :(

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