New Fuel Pump, Now Hard To Start, On Mornings Runs Rough For A Few Seconds

[Shaydsta R34]

Hey people,

I'm doing a turbo upgrade on my R34 GT-T, and before i have put new turbo and stuff on, my mate installed a bosch 044 fuel pump yesterday.

Now as i have never done this before i'm not sure what to expect.

So symptoms that have occurred since the installation ;

i) On the highway in 4th and 5th gear, if i put my foot down there is a delay of about half a second before the car will accelerate.

ii) Even after "priming" the fuel pump (switching to 'on' so the fuel pump builds pressure), it still takes a bit to get started (turns over for a bit then sickly comes to life)

iii) This morning i "primed" it, waited for the fuel pump to stop pumping, then turned over the engine, it kept turning over but wouldn't start, so i tried again straight after and this time, once again, it came to life, but very sickly, it ran rough, felt like a cylinder wasn't firing. i then let it idle at around 2000rpm, and all went back to normal after a few seconds.

Now I'm getting told different things, Some people say it's the fuel pressure reg, and others say it needs to be earthed to the chassis and not use the existing wires. As far as i know, the filter sock reaches the bottom (so my mate says), so i'm not sure what the problem could be.

This is the first time i have touched the fuel line on any car so i'm a bit of a virgin to it.

I'm not sure if this will impact it, but when i was driving to go get the new pump installed, i was cruising along the highway at around 2.5k rpm, and the car hesitated for a second (lost power, but only for a second), engine light came on, then went back to normal and engine light went off.

List of engine/exhaust modifications are:

Superspark coils,

0.8mm gap plugs

3" to 80mm exhaust, no cat (still waiting for one that fits)

Pod filter with standard AFM

and that's about it that i think could effect it.

I have an AEM tru boost, but was only running stock boost when this happened.

Thank you in advance for anyone who can help.

Shaydan

[mad082]

i thought the 044 was an external pump and the 040 was the internal pump? maybe that is part of your problem. or it may have nothing to do with it and it may be fine

if your old pump was dodgy then putting a new pump in may be showing another issue that was previously hidden by a failing fuel pump. this may be something simple like a dirty afm or fouled spark plugs.

[Shaydsta R34]

The stock Fuel pump was fine,

And yeh you're right about it being external, but you can still use them internally.

The FPR has arrived but not fitted and it's still 50/50, c-red and hyperdrive told me over the phone that i have wasted my money because it's not needed, and others say i need it.

I'm not sure if the FPR is related to the hesitation when in 4th and 5th.